Parallel and Distributed Resource Allocation with Minimum Traffic Disruption for Network Virtualization

Parallel and Distributed Resource Allocation with Minimum Traffic Disruption for Network Virtualization

Parallel and Distributed Resource Allocation with MinimumTraffic Disruption for Network Virtualization

 

ABSTRACT:

Wireless network virtualization has been advocated as one of the most promising technologies to provide multifarious services and applications for the future Internet by enabling multiple isolated virtual wireless networks to coexist and share the same physical wireless resources. Based on the multiple concurrent virtual wireless networks running on the shared physical substrate, service providers can independently manage and deploy different end-users services. This paper proposes anew formulation for bandwidth allocation and routing problem for multiple virtual wireless networks that operate on top of asingle substrate network to minimize the operation cost of the substrate network.We also propose a preventive traffic disruption model for virtual wireless networks to minimize the amount of traffic that service providers have to reduce when substrate links fail by incorporating `1-norm into the objective function. Dueto the large number of constraints in both normal state and link failure states, the formulated problem becomes a large-scale optimization problem and is very challenging to solve using the centralized computational method. Therefore, we propose the decomposition algorithms using the alternating direction method of multipliers (ADMM) that can be implemented in a parallel and distributed fashion. The simulation results demonstrate the computational efficiency of our proposed algorithms as well as the advantage of the formulated model in ensuring the minimal amount of traffic disruption when substrate links fail.

 OBJECTIVE:

Preventive Traffic Disruption Modeling: We propose apreventive traffic disruption model for virtual networkswhen a substrate link failure event happens. We alsoincorporate `1-norm into the objective function to ensurethe minimal amount of traffic reduction of SPs.

  • Parallel and Distributed Implementation: We propose two algorithms based on the ADMM decomposition technique. The first algorithm provides a parallel computational framework that can be solved concurrently at different computing nodes, and the second algorithm allows SPs and substrate links distributive solve local problems to achieve the global optimal solution.
  • Performance Evaluation: We evaluate the performance ofour proposed algorithms using various system parameters.We also demonstrate the efficacy of our preventive model in reducing the amount of traffic reduction.

INTRODUCTION:

The rapid growth of traffic demand and application prolife ration creates irresistible challenges for traditional wireless networks to ensure the qualify of service (QoS) and quality of experience of subscribers. However, due to the inefficient resource utilization and the tightly coupling between hardware and wireless protocols caused by the inherent design, the current wireless networks and Internet can hardly meet such great expectations without fundamentally changing network architectures. Recently, wireless network virtualization has been proposed as one of the key enablers to overcome the ossification of the current Internet by allowing diverse services and applications coexist on the same infrastructure. In wireless network virtualization,the traditional Internet service providers are decoupled into infrastructure providers (InPs) who own and manage only infrastructure resources, and service providers (SPs) who lease resources from InPs and concentrate on providing services to subscribers. The physical resources that belong to different InPs are virtualized into a single physical substrate network.Consequently, multiple virtual wireless networks are deployed and operated on top of the single substrate network  Asa result, multiple experiments can be performed and tested simultaneously on isolated virtual networks without affecting the operation of the others. Therefore, wireless network virtualization offers great opportunities to shorten the process of evaluating and deploying innovative technologies. Moreover,by sharing the same infrastructure resources, expenses of wireless network expansion and operation can be significantly reduced.

EXISTING SYSTEM:

  1. Liu, F. Yu, H. Ji, and V. Leung, “Virtual resource management ingreen cellular networks with shared full-duplex relaying and wireless virtualization: A game-based approach,” IEEE Transactions on Vehicular Technology, vol. 65, no. 9, pp. 7529–7542, Sep. 2016.

To efficiently allocate physical resources to multiple virtual wireless networks and find the optimal routing solution in each virtual network operated by SPs.

  1. Chen, F. R. Yu, H. Ji, G. Liu, and V. C. M. Leung, “Distributed

virtual resource allocation in small-cell networks with full-duplex selfback haulsand virtualization,” IEEE Transactions on Vehicular Technology,vol. 65, no. 7, pp. 5410–5423, Jul. 2016.

A resourceallocation in virtualized small cell networks with full duplexself-backhauls is formulated.

PROPOSED SYSTEM:

We also propose a preventive traffic disruptionmodel for virtual wireless networks to minimize the amount oftraffic that service providers have to reduce when substrate linksfail by incorporating `1-norm into the objective function. Due

to the large number of constraints in both normal state and link failure states, the formulated problem becomes a large-scale optimization problem and is very challenging to solve using the centralized computational method. Therefore, we propose the decomposition algorithms using the alternating direction method of multipliers (ADMM) that can be implemented in a parallel and distributed fashion. The simulation results demonstrate the computational efficiency of our proposed algorithms as well as the advantage of the formulated model in ensuring the minimal amount of traffic disruption when substrate links fail.

BLOCK DIAGRAM:

Parallel and Distributed Resource Allocation

DESCRIPTION:

The bandwidth allocation can satisfy traffic demands for all virtual networks only when all substrate links are fully available, which we will refer as the normal state. However, unpredictable wireless network events such as link failures may occur anytime. Although when a link failure event happens, the network controller can reformulate the problem in with new system parameters to reallocate bandwidth for all virtual networks, it will take acertain amount of time to wait for network re-convergence.Since different SPs target different types of services and may have stringent reliability and QoS requirements, this performance degradation and severe discontinuation will be intolerable to end-users.

ADVANTAGES:

  • Can be solved concurrently at different computing nodes
  • SP and substrate link distributively solve the local problem to converge to the global optimal solution.

SYSTEM REQUIREMENTS:

HARDWARE REQUIREMENTS:

  • System : Pentium Dual Core.
  • Hard Disk : 120 GB.
  • Monitor : 15’’ LED
  • Input Devices : Keyboard, Mouse
  • Ram : 1GB

SOFTWARE REQUIREMENTS:

  • Operating system : Windows 7.
  • Coding Language : MATLAB
  • Tool : MATLAB R2013A

REFERENCE:

Hung Khanh Nguyen, Student Member, IEEE, Yanru Zhang, Member, IEEE,Zheng Chang, Member, IEEE, and Zhu Han, Fellow, IEEE, “Parallel and Distributed Resource Allocation with MinimumTraffic Disruption for Network Virtualization”, IEEE Transactions on Communications, 2017.

 

Optimal Resource Allocation for Power-Efficient MC-NOMA with Imperfect Channel State Information

Optimal Resource Allocation for Power-Efficient MC-NOMA with Imperfect Channel State Information

 

ABSTRACT:

In this paper, we study power-efficient resource allocation for multicarrier non-orthogonal multiple access (MCNOMA)systems. The resource allocation algorithm design is formulated as a non-convex optimization problem which jointly designs the power allocation, rate allocation, user scheduling,and successive interference cancellation (SIC) decoding policy for minimizing the total transmit power. The proposed framework takes into account the imperfection of channel state information at transmitter (CSIT) and quality of service (QoS) requirements of users. To facilitate the design of optimal SIC decoding policy on each sub carrier, we define a channel-to-noise ratio outage threshold. Subsequently, the considered non-convex optimization problem is recast as a generalized linear multiplicative programming problem, for which a globally optimal solution is obtained via employing the branch-and-bound approach. The optimal resource allocation policy serves as a system performance benchmark due to its high computational complexity. To strike a balance between system performance and computational complexity,we propose a suboptimal iterative resource allocation algorithm based on difference of convex programming. Simulation results demonstrate that the suboptimal scheme achieves a close to-optimal performance. Also, both proposed schemes provide significant transmit power savings than that of conventional orthogonal multiple access (OMA) schemes.

 OBJECTIVE:

                  To address the CSIT imperfectness for resource allocation designs, including no-CSIT worst-case optimization and stochastic approaches The assumption of no-CSIT usually results in a trivial equal power allocation strategy without any preference in resource allocation Besides,it is pessimistic to assume no-CSIT since some sorts of CSIT,e.g., imperfect channel estimates or statistical CSIT, can be easily obtained in practical systems exploiting handshaking signals

 INTRODUCTION:

Recently, non-orthogonal multiple access (NOMA) has received considerable attentions as a promising multiple access technique for the fifth-generation (5G) wireless communication networks. The basic rationale behind NOMA is to exploit the power domain for users multiplexing and to employ successive interference cancellation (SIC) at receivers to remove the multiple access interference (MAI).In contrast to conventional orthogonal multiple access (OMA)schemes, NOMA is a promising solution to fulfil the demanding requirements of the 5G communication systems,such as massive connectivity, low latency, high spectral efficiency, and enhanced user fairness. In particular, NOMA can support overloaded transmission and increase the system throughput for given limited spectrum resources by enabling simultaneous transmission of multiple users utilizing the same frequency resources. Also, multiple users with heterogeneous traffic requests can be served concurrently on the same frequency band to reduce the latency and to enhance the resource allocation fairness.

 EXISTING SYSTEM:

  1. Wei, D. W. K. Ng, and J. Yuan, “Power-efficient resource allocation
    for MC-NOMA with statistical channel state information,” in Proc. IEEE
    Global Commun. Conf.
    , Dec. 2016, pp. 1–7

Under statistical CSIT, proposed an optimal SIC decoding policy for a two-user MC-NOMA system and a sub optimal power-efficient resource allocation scheme with an equal rate assignment.

  1. Cui, Z. Ding, and P. Fan, “A novel power allocation scheme under
    outage constraints in NOMA systems,” IEEE Signal Process. Lett.,
    vol. 23, no. 9, pp. 1226–1230, Sep. 2016

Anoptimal SIC decoding policy for single-carrier NOMA systemswith more than two users multiplexing under statistical CSIT.

DRAWBACKS:

These two preliminary works did notconsider the joint resource allocation design for MC-NOMAsystems and directly applying the designs to the considered
MC-NOMA systems may lead to unsatisfactory performance.

 PROPOSED SYSTEM:

We proposed an optimal resource allocation algorithm, in which the optimal SIC
decoding policy was determined by the CNR outage threshold. We propose a suboptimal iterative resource allocation algorithm based on difference of convex programming. Simulation results demonstrate that the suboptimal scheme achieves a close to-optimal performance. Also, both proposed schemes provide significant transmit power savings than that of conventional orthogonal multiple access (OMA) schemes.

 BLOCK DIAGRAM:

 DESCRIPTION:

We study the power-efficient resource allocation design for downlink MC-NOMA systems under imperfect CSIT, where each user imposes its own QoS requirement. The joint design of power allocation, rate allocation, user scheduling, and SIC decoding policy is formulated as a non-convex optimization problem to minimize the total transmits power. To facilitate the design of optimal SIC decoding order, we define the channel-to-noise ratio (CNR) outage threshold, which includes the joint effect of channel conditions and QoS requirements of users. Based on the optimal SIC decoding policy, we propose an optimal resource allocation algorithm via the branch-and-bound (B&B) approach which serves as a performance benchmark for MC-NOMA systems.

 ADVANTAGES:

  • Significant transmit power savings.
  • Enhanced robustness against channel uncertainty via exploiting the heterogeneity.

SYSTEM REQUIREMENTS:

HARDWARE REQUIREMENTS:

  • System : Pentium Dual Core.
  • Hard Disk : 120 GB.
  • Monitor : 15’’ LED
  • Input Devices : Keyboard, Mouse
  • Ram : 1GB

SOFTWARE REQUIREMENTS:

  • Operating system : Windows 7.
  • Coding Language : MATLAB
  • Tool : MATLAB R2013A

REFERENCE:

Zhiqiang Wei, Student Member, IEEE, Derrick Wing Kwan Ng, Member, IEEE, Jinhong Yuan, Fellow, IEEE and Hui-Ming Wang, Senior Member, IEEE, “Optimal Resource Allocation for Power-Efficient MC-NOMA with Imperfect Channel State Information”, IEEE Transactions on Communications, 2017.

Non-Orthogonal Random Access (NORA) for 5G Networks

Non-Orthogonal Random Access (NORA) for 5G Networks

Non-Orthogonal Random Access (NORA) for 5G Networks

 

ABSTRACT:

The massive amounts of machine-type user equipments (UEs) will be supported in the future fifth generation (5G)networks. However, the potential large random access (RA) delay calls for a new RA scheme and for a detailed assessment of its performance. Motivated by the key idea of non-orthogonal multiple access, the non-orthogonal random access (NORA)scheme based on successive interference cancellation (SIC) is proposed in this paper to alleviate the access congestion problem.Specifically, NORA utilizes the difference of time of arrival to identify multiple UEs with the identical preamble, and enables power domain multiplexing of collided UEs in the following access process, while the base station performs SIC based on the channel conditions obtained through preamble detection. Our analysis show that the performance of NORA is superior to the conventional orthogonal random access (ORA) scheme in terms of the preamble collision probability, access success probability and throughput of random access. Simulation results verify our analysis and further show that our NORA scheme can improve the number of the supported UEs by more than 30%. Moreover,the number of preamble transmissions and the access delay for successfully accessed UEs are also reduced significantly by using the proposed random access scheme.

 OBJECTIVE:

  • We propose a novel NORA mechanism which utilizes the spatial distribution characteristic of UEs. NORA integrates the arrival time-based multi-preamble detection and distance-based RAR reception schemes to effectively improve the preamble transmission success probability. The corresponding RAR message format is tailored for practical realizations.
  • We derive an analytical model to investigate the transient behavior of the NORA process with non-stationary arrivals. Realistic assumptions, such as UEs’ positions and channel conditions, are considered to show practical results.
  • We provide a comprehensive analysis of the NORA performance, including throughput of preamble transmission and random access, collision/access success probability, the cumulative distribution function (CDF) of the number of preamble transmissions and access delay for the successfully accessed UEs, average number of preamble transmissions and average access delay.
  • With the proposed NORA scheme, the throughput of random access process is increased by more than 30%. Moreover, the average number of preamble transmissions and average access delay are reduced remarkably, and are only half as much as those of the ORA scheme in the best case.

 INTRODUCTION:

The fifth generation (5G) networks will support tens of thousands user equipments (UEs) per cell in the near future. Each UE performs a random access (RA)procedure for initial uplink access to connect and synchronize with its base station. When the number of UEs is tremendous, the RA procedure is inefficient due to the frequent transmission collisions, which lead to network congestion,unexpected delay, high power consumption, and radio resource wastage. Hence, the RA procedure becomes the bottleneck of 5G networks’ performance In current LTE systems, the RA procedure consists of a four message handshake between the UE and the eNodeB (which is referred to as orthogonal random access (ORA) scheme in the following sections). The four messages include Preamble, Random Access Response (RAR), Initial Layer 3 message (Msg3) and Contention Resolution (CR). A periodic sequence of time-frequency resources called random access slots (RA slots) are reserved in the Physical Random Access Channel(PRACH) for preamble transmission. Whenever a UE triggers the RA procedure, it transmits a preamble randomly chosen from the available orthogonal pseudo-random preambles periodically broadcast by the eNodeB in the next available RA slot. There are up to 64 available preambles within each cell. So if more than 64 UEs make RA attempts in one specific RA slot, the collision is inevitable.

EXISTING SYSTEM:

  1. T. Wiriaatmadja and K. W. Choi, “Hybrid random access and data transmission protocol for machine-to-machine communications in cellular networks,” IEEE Trans. Wireless Commun., vol. 14, no. 1, pp. 33–46, Jan. 2015.

Achieve uplink scheduling and random access network (RAN) overload control, in which the access barring parameter is adaptively changed based on the amount of available RBs and the traffic load

  1. Duan, V. Shah-Mansouri, Z. Wang, and V. Wong, “D-ACB:Adaptive congestion control algorithm for bursty M2M traffic in LTE networks,” IEEE Trans. Veh. Technol, vol. 65, no. 12,pp. 9847–9861, Dec. 2016.

Two dynamic ACB algorithms for fixed and dynamic preamble allocation schemes are proposed to determine the barring factors without prior knowledge of the number of MTC devices.

PROPOSED SYSTEM:

We have proposed the NORA scheme to alleviate the potential access congestion problem regarding themassive-connection scenarios in 5G networks. Specifically, the spatial distribution characteristics of UEs were utilized to realize multi-preamble detection and RAR reception, which effectively improves the preamble transmission success probability.Moreover, NORA allows simultaneous message transmission of multiple UEs, thus alleviates the demand on limited PUSCH resources. In addition, we have presented the analytical model to investigate the transient behavior of the NORA process with non-stationary arrivals under realistic assumptions. Besides,a comprehensive evaluation of our proposition is given,including throughput, access success probability, number of preamble transmission and access delay. Simulation results indicate that NORA outperforms ORA in terms of all the considered metrics, especially for a relatively large number of UEs (e.g. 50000 UEs)

BLOCK DIAGRAM:

Non-Orthogonal Random Access (NORA)

 DESCRIPTION:

We give a detailed description of the NORA scheme, which consists of PRACH preamble transmission,random access response, initial layer 3 message transmission and contention resolution Each UE first receives the system information broadcast on Physical Broadcast Channel (PBCH) and acquires necessary configuration information to complete the RA process. The information includes PRACH configuration information such as PRACH Configuration Index, PRACH Frequency Offset, Root Sequence Index, etc. and RACH configuration information such as Number of RA Preambles, Maximum Number of Preamble Transmission, RA Response Window Size, Power Back-off Offset, MAC Contention Resolution Timer, etc. When a UE starts to perform random access,

it randomly selects a preamble sequence from the available preambles broadcast by the base station and transmits it in the next available RA slot. Preamble sequences are identified by their Random Access Preamble Identity (RAPID).There is also a one-to-one mapping between Random Access Radio Network Temporary Identifier (RA-RNTI) and the time/frequency resources used by the PRACH preamble.

ADVANTAGES:

  • NORA outperforms ORA in terms of all the considered metrics, especially for a relatively large number of UEs.
  • Compared with ORA, NORA can increase the throughput of the RA process by more than 30%.
  • NORA manages to halve the required preamble transmissions and access delay when the total number of UEs is near the RA throughput

SYSTEM REQUIREMENTS:

HARDWARE REQUIREMENTS:

  • System : Pentium Dual Core.
  • Hard Disk : 120 GB.
  • Monitor : 15’’ LED
  • Input Devices : Keyboard, Mouse
  • Ram : 1GB

SOFTWARE REQUIREMENTS: 

  • Operating system : Windows 7.
  • Coding Language : MATLAB
  • Tool : MATLAB R2013A

REFERENCE:

Yanan Liang, Student Member, IEEE, Xu Li, Member, IEEE, Jiayi Zhang, Member, IEEEand Zhiguo Ding, Senior Member, IEEE, “Non-Orthogonal Random Access (NORA) for 5GNetworks”, IEEE Transactions on Wireless Communications, 2017.

Non-linear Distortion Cancellation and Symbol-based Equalization in Satellite Forward Links

Non-linear Distortion Cancellation and Symbol-based Equalization in Satellite Forward Links

 

ABSTRACT:

In this paper, a low-complexity symbol-based equalizerthat performs non-linear distortion cancellation is proposedfor application at the user terminal in the DVB-S2X satelliteforward link. The channel is comprehensively modelled, includingthe non-linear travelling wave tube amplifier (TWTA) characteristics,the input-multiplexing (IMUX) and output-multiplexing(OMUX) filter responses at the satellite transponder, and thephase noise at the user terminal, according to the very-smallaperture terminal (VSAT) reference scenario. Two detectors inthe cancellation loop are considered, comparing the packeterrorrate (PER) performance of simple maximum likelihood(ML) demodulation with hard decision to soft informationexchange with low-density parity-check (LDPC) decoder, andshowing only marginal improvement with the latter solution.The PER performance is compared against a number of predistortiontechniques at the transmitter, such as dynamic datapre-distortion, successive data pre-distortion, and static data predistortion.The novel receiver demonstrates superior performanceeven with one iteration of distortion cancellation, while thejoint application of successive data pre-distortion and iterativesymbol-based equalization shows up to 4:95-dB energy efficiencygain for 32-level amplitude and phase-shift keying (32-APSK).The computational complexity is also evaluated. The improvedreceiver is particularly suitable for application with higher ordermodulation, a wide-band carrier, and low roll-off factors.

 OBJECTIVE:

  • To reconstruct and cancel the interfering component, using channel models based on measured responses of the deterministic distortion sources along the chain, such as IMUX/OMUX responses and TWTA transfer characteristics.
  • To non-linear distortion, memory effects in the form of ISI are also compensated due to the fact that the equalizer operates on a large block of consecutive symbols.
  • To estimate and cancel the interference. The performance of the symbol-based equalizer with non-linear distortion cancellation has been evaluated

 INTRODUCTION:

The recently published extension of the second-generationdigital video broadcasting system for satellite broadcasting andunicasting (DVB-S2X) standard introduces a number ofimprovements for the air interface of the satellite forward link.Key advances include:

 1) wide-band operation with transponderbandwidths of 225 MHz for application with Ka-bandtransponders,

 2) higher-order amplitude and phase-shift keying(APSK) modulation up to 256-APSK and additional lowdensityparity-check (LDPC) codes for more efficient resourceutilization with finer signal-to-noise ratio (SNR) thresholdgranularity, and

3) lower roll-off factors down to 5% in orderto reduce the bandwidth occupied by a carrier.

Targeting applicationsin broadcast or unicast broadband scenarios for highthroughput-satellite (HTS) systems these advances enablethe shift towards more bandwidth-demanding applications andservices, the adaptation to traffic demand across the coveragearea, and the decrease of the cost per transmitted bit. Transmission over the satellite forward-link channel suffersfrom linear and non-linear distortions. In order to maximizethe spectral efficiency, state-of-the-art satellite communicationsystems resort to single-carrier utilization of the satellitetransponder bandwidth, using a very low roll-off factor andvery high symbol baud rates, e.g., for 4K televisionbroadcasting in the direct-to-home (DTH) scenario or broadbandinteractive Internet protocol (IP) services in the verysmall-aperture terminal (VSAT) scenario. HTS links with awide-band single-carrier transponder are also applied to coveremerging markets for mobile platforms, such as broadbandconnectivity on airplanes, cruise ships and trains, as well asprofessional applications.

EXISTING SYSTEM:

Implementation Guidelines for the Second Generation System for Broadcasting,Interactive Services, News Gathering and Other BroadbandSatellite Applications; Part II: S2-Extensions (DVB-S2X), Digital VideoBroadcasting (DVB) Std. ETSI TR 102 376-2, Mar. 2015.

 The energy efficiency of the system when high OBO is applied. Advanced non-linear compensation techniques include a number of pre-distortion techniques at the transmitter,such as data pre-distortion.

  1. Karam and H. Sari, “Analysis of predistortion, equalization, and ISI cancellation techniques in digital radio systems with nonlinear transmit amplifiers,” IEEE Trans. Commun., vol. 37, no. 12, pp. 1245–1253, Dec.1989.

A common approach to handle the ISI is equalization where knowledge of the channel, obtained for instance by channel estimation, is used to minimize the ISI. A linear equalizer has been introduced in the DVB-S2X receiver.

PROPOSED SYSTEM:

In this paper, symbol-based equalization with non-lineardistortion cancellation has been proposed as an addition to thestate-of-the-art linear equalizer at the user terminal receiver inthe DVB-S2X satellite forward link. The improved receiver isparticularly suitable for application with the recently specifiedDVB-S2X reference scenarios, including wide-band carrierswith low roll-off factors, high symbol baud rates, and high ordermodulations. The performance of the receiver has beenassessed for a single-carrier 36-MHz transponder with higher

34-MBaud symbol rate with lower roll-off of 5%, as well aswith lower 27:5-MBaud symbol rate and higher roll-off of20%, using a comprehensive model of the satellite forward linkchannel with IMUX and OMUX filter responses, nonlinearTWTA characteristics, a phase noise mask and AWGN.

 BLOCK DIAGRAM:

 DESCRIPTION:

At the gateway transmitter, a stream ofdata packets with 1504 bits per packet are encoded by meansof a FEC scheme. In DVB-S2X [1], first, a Bose-Chaudhuri-Hocquenghem (BCH) encoder is applied, followed by anLDPC encoder and bit interleaver. The resulting FEC framewith length of up to 64800 bits is mapped to symbols, usingAPSK modulation with constellations up to 256-APSK at themodulator. In the VSAT scenario, the symbols are grouped inbundled physical-layer (PL) frames with up to 67920 symbolsper PL frame, which are in term grouped in superframes with612540 symbols per superframe. A key feature introduced withthe superframe format are the P2 modulated pilot symbolsincluded in each DVB-S2X bundled PL frame. These pilotsare inserted after the PL header, and are modulated similarlyto the modulation in the corresponding bundled PL frame,representing all constellation points. The information on thesepilots can be used in advanced channel estimation techniques,e.g., for estimation of the received constellation centroids usedas a reference in the soft demapper and decoder at the receiver,or in the training of channel models used in a variety ofchannel compensation techniques

ADVANTAGES:

  • These performance gains at low number of iterations, in order to maintain low complexity of the receiver.
  • Enabling the increase of both user rates and system capacity.
  • Imperfect channel estimation and robustness of the equalizer with varying channel characteristics.

SYSTEM REQUIREMENTS:

HARDWARE REQUIREMENTS:

  • System : Pentium Dual Core.
  • Hard Disk : 120 GB.
  • Monitor : 15’’ LED
  • Input Devices : Keyboard, Mouse
  • Ram :

SOFTWARE REQUIREMENTS:

  • Operating system : Windows 7.
  • Coding Language : MATLAB
  • Tool : MATLAB R2013A

REFERENCE:

SvilenDimitrov, “Non-linear Distortion Cancellation andSymbol-based Equalization in Satellite Forward”, IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS, 2017.

 

Multicarrier Approaches for High-baudrate Optical-Fiber Transmission Systems with a Single Coherent Receiver

Multicarrier Approaches for High-baudrate Optical-Fiber Transmission Systems with a Single Coherent Receiver

Multi carrier Approaches for High-baudrate Optical-Fiber Transmission Systems with a Single Coherent Receiver

 

ABSTRACT:

In this paper, we show the remarkable timing error (TE) and residual chromatic dispersion(CD) tolerance improvements of the filter bank multicarrier (FBMC) over orthogonal frequency division multiplexing (OFDM) for high-baudrate spectral slicing transmitter and a single coherent receiver transmissions. For a 512 Gb=s 16 quadrature amplitude modulated (16QAM) spectrum slicing system at 1600km of fiber transmission, the FBMC-based system reduces TE and residual CD penalties by more than 1:5 dB and 3 dB in comparison to the OFDM-based, respectively

 OBJECTIVE:

  • To mitigate the impact of timing mismatch among optical paths we also consider here filter bank multicarrier (FBMC) – an evolution of OFDM in which the rectangular pulse shaping is replaced by a modified raised cosine filtering the application of multicarrier techniques i.e. OFDM and FBMC for a SS system of 128 Gbaud 16QAM (leading to a total of 512 Gb=s for a single polarization) with a single coherent receiver.
  • The comparison of OFDM and FBMC was provided in terms of timing error (TE) (also called delay mismatch – DM) and residual chromatic dispersion (CD) tolerances.

INTRODUCTION:

To meet the rapidly increasing demand for capacity, high spectral efficiency (SE) systems withcost-effective implementations have gained a lot of attention recently. The concept ofsuperchannel has been proposed to push the data rate per interface up to the order of Tb=s.Moreover, due to the high bandwidth of commercially available photodiodes, superchannel can beeffectively received and processed by a single coherent receiver, leading to a significant reductionin the overall cost per bit. However, up to now, it is still very challenging to generate superchannelswith over 100 GHz of bandwidth using a single in-phase quadrature (IQ) optical modulator. As aresult, alternative approach such as spectral slice (SS) engineering of the spectrum hasbeen proposed to generate high-baudratesuperchannel signals. The report in demonstratesa record symbol rate of 127:9 Gbaud 16QAM with the implementation of Nyquist-pulse shapingand spectrum slicing synthesis techniques. However, in this work, a Q-factor penalty of around7 dB was observed. This penalty was due to the imperfect receiver and the timing mismatch(timing error) among optical paths, which always exists before the coupling of spectral slices atthe transmitter.

EXISTING SYSTEM:

  1. Chandrasekhar and X. Liu, “OFDM based superchannel transmission technology,” Journal of Lightwave Technology, vol. 30, no. 24, pp. 3816–3823, 2012.

 Multi carrier modulation formats, such as orthogonal frequency division multiplexing (OFDM), have been considered as potential techniques for the application of high speed, long-haul, and multi-wavelength optical networks due to the capability of inter-symbol interference (ISI) mitigation using simple digital signal processing (DSP) techniques

  1. Mardoyan, M. A. Mestre, P. Jennev´ e, L. Schmalen, A. Ghazisaeidi, and P. Tran, “Transmission of Single-CarrierNyquist-Shaped 1-Tb/s Line-Rate Signal over 3,000 km,” in Optical Fiber Communication Conference (OFC), no. 1,2015, pp. 3–5.

Delay lines (DLs) were required to keep the timing mismatch below 1 ps for the Nyquist-pulse shaping. Such timing-mismatch requirement is very challenging for practical implementation and thus, alternative modulation formats with higher tolerance to timing mismatch among optical paths are highly desirable for high baud rate super channel transmissions

 PROPOSED SYSTEM:

We have implemented the multi carrier-based 128 Gbaud 16QAM SS systems for the long-haul transmission distance. We evaluated and compared the performance of the SS system with OFDM and FBCM in different configurations by numerical simulations. The results showed that the FBMC-based SS system was superior to the OFDM based SS system in terms of robustness to the timing errors and delay spreads at the cost of slightly increasing the complexity.FBMC, therefore, would be a very potential candidate for spectral slice engineering applications

BLOCK DIAGRAM:

Multicarrier Approaches for High-baudrateOptical

 DESCRIPTION:

Both OFDM and FBMC inherit the same principle of multicarrier transmission systems.The transmitted signal, y(t), is the sum of the signals on all channels (or subcarriers) and givenas

where Xk;_ is the data on the kth subcarrier at the _ multicarrier symbol, fk is the carrier frequencyof the kth subcarrier, N is the number of subcarriers, Ts is the multicarrier symbol period, and pT (t)is the prototype filter (PF) at the transmitter which is normally designed once for all subcarriers.

The term pT (t 􀀀_Ts)ej2_tfk implies that the PF at the kth subcarrier in the _thsymbol can beregarded as the time delay – frequency shifted version of the same prototype low-pass filter pT (t).

If we sample the transmitted signal at the sample rate of N=Ts, the simplified discrete transmittedsignal from the eq. (1) can be rewritten as

.The difference between OFDM and FBMC originates from the PF design. For OFDM, the PFis simply a rectangular pulse during a symbol period, i.e. pT (t) = const:;0 6 t <Ts while it istypically a modified raised cosine, root-raised cosine or root Nyquist in the case of FBMC. To maximize the signal-to-noise ratio (SNR) at the receiver, the matched filtering configuration is utilized, i.e. pR(t) = pT (􀀀t).

ADVANTAGES:

  • The FBMC SS system was also more robust to the residual CD than OFDMs by 3 dB and 4 dB at 1% and 3% of the residual CD, respectively.
  • This comes from the fact that the FBMC PFs impulse response is four times longer than the OFDMs.

SYSTEM REQUIREMENTS:

HARDWARE REQUIREMENTS: 

  • System : Pentium Dual Core.
  • Hard Disk : 120 GB.
  • Monitor : 15’’ LED
  • Input Devices : Keyboard, Mouse
  • Ram : 1GB

SOFTWARE REQUIREMENTS:

  • Operating system : Windows 7.
  • Coding Language : MATLAB
  • Tool : MATLAB R2013A

REFERENCE:

Tu T. NGUYEN, Son T. LE, Qinwei HE, Ludo V. COMPERNOLLE,Marc WUILPART, and Patrice ME´GRET, “Multicarrier Approaches for High-baudrate Optical-Fiber Transmission Systems with a Single Coherent Receiver”, IEEE Photonics Journal, 2017.

Multi-antenna Wireless Legitimate Surveillance Systems: Design and Performance Analysis

Multi-antenna Wireless Legitimate Surveillance Systems: Design and Performance Analysis

Multi-antenna Wireless Legitimate Surveillance Systems: Design and Performance Analysis

ABSTRACT:

To improve national security, government agencies have long been committed to enforcing powerful surveillance measures on suspicious individuals or communications. In this paper, we consider a wireless legitimate surveillance system,where a full-duplex multi-antenna legitimate monitor aims to eaves drop on a dubious communication link between a suspicious pair via proactive jamming. Assuming that the legitimate monitor can successfully overhear the suspicious information only when its achievable data rate is no smaller than that of the suspicious receiver, the key objective is to maximize the eaves dropping non-outage probability by joint design of the jamming power,receive and transmit beam formers at the legitimate monitor.Depending on the number of receive/transmit antennas implemented,i.e., single-input single-output, single-input multiple output,multiple-input single-output and multiple-input multiple output (MIMO), four different scenarios are investigated. For each scenario, the optimal jamming power is derived in closed form and efficient algorithms are obtained for the optimal transmit/receive beam forming vectors. Moreover, low-complexity suboptimal beam forming schemes are proposed for the MIMO case. Our analytical findings demonstrate that by exploiting multiple antennas at the legitimate monitor, the eaves dropping non-outage probability can be significantly improved compared to the single antenna case. In addition, the proposed sub optimal transmit zero-forcing scheme yields similar performance as the optimal scheme.

OBJECTIVE:

  • Depending on the number of receive/transmit antennas implemented at the legitimate monitor, i.e., single-input single-output (SISO), single-input multiple output (SIMO), multiple-input single-output (MISO) and multiple-input multiple-output (MIMO), four different scenarios are studied.
  • Three low-complexity suboptimal beam forming schemes are proposed, namely, transmit zero-forcing (TZF)/ maximum ratio combing (MRC), maximum ratio transmission (MRT)/ receive zero-forcing (RZF), and MRT/ MRC.
  • The findings of the paper suggest that, deploying multiple antennas is an effective means to enhance the system performance.

INTRODUCTION:

Wireless communications provide an efficient and convenientmeans for establishing connections between people.However, due to the open and broadcast nature of the wirelessmedium, wireless communications are particularly susceptibleto security breaches, hence establishing reliable andsafe connections is a challenging task. Responding to this,physical layer security, as a promising technique to enablesecure communications, has attracted considerable attentions

in recent years, and various sophisticated techniquessuch as artificial noise  and security-oriented beamforminghave been proposed to enhance the secrecyperformance.In the physical layer security framework, the eavesdroppersare illegitimate adversaries, who intend to breach the confidentialityof a private conversation. On the other hand, wirelesscommunications also facilitate the collaboration between thecriminals or terrorists, thereby posing significant threats onnational security. Therefore, to prevent crimes or terror attacks,there is a strong need for the government agencies tolegitimately monitor any suspicious communication links todetect abnormal behaviors, such as communications containingsensitive word combinations, addressing information, or otherfactors with a frequency that deviates from the average.

 EXISTING SYSTEM:

  1. Xu, L. Duan, and R. Zhang, “Proactive eavesdropping via cognitive jamming in fading channels,” accepted to appear in IEEE Trans. Wireless Commun., 2017. 
  • In order to enable full-duplex operation, the legitimate monitor is equipped with two antennas, one for eavesdropping and the other for jamming. Also, an ideal assumption, namely, perfect self-interference cancellation, is adopted.
  1. Zeng and R. Zhang, “Wireless information surveillance via proactive eavesdropping with spoofing relay,” IEEE J. Sel. Topics Signal Process., vol. 10, no. 8, pp. 1449–1461, Dec. 2016.
  • The authors proposed three possible spoofing relay strategies to maximize the achievable eavesdropping rate.

PROPOSED SYSTEM:

In this paper, we propose to adopt multiple antennas at the legitimate monitor for performance enhancement. The motivation of using multiple antennas is two-fold, namely, enabling self interference mitigation in the spatial domain and adjusting the effective jamming power observed at the suspicious receiver.For the considered multi-antenna wireless legitimate surveillance systems, we study the optimal joint design of jamming power and beamforming vectors. To reduce the complexity, intuitive suboptimal beamforming schemes are also proposed,and the achievable eavesdropping non-outage probability of the proposed schemes are examined.

BLOCK DIAGRAM:

Multi-antenna Wireless Legitimate SurveillanceSystems

DESCRIPTION:

We consider a three-node point-to-point legitimate surveillancesystem as shown in Fig. 1, where a legitimate monitorE aims to eavesdrop a dubious communication link betweena suspicious pair S and D via jamming. It is assumed thatthe suspicious transmitter and receiver are equipped with a The received signal at the suspicious receiver D can beexpressed as

where PS denotes the transmit power of the suspicious transmitter,hsd is the channel coefficient of the S → D linkwhich is a zero-mean complex Gaussian random variable withvariance _1. The 1 × Nt vector hed denotes the jammingchannel between E and D, whose entries are identically andindependently distributed (i.i.d.) zero-mean complex Gaussianrandom variables with variance _3 and wt is the transmitbeamforming vector at the legitimate monitor with ||wt|| = 1.

In addition, s is the information symbol with unit power, whilex denotes the jamming symbol with E{|x|2} = pd satisfying0 ≤ pd ≤ PJ where PJ denotes the maximum jamming power.Finally, nd is the zero-mean additive white Gaussian noise(AWGN) with variance ND.Similarly, the received signal at the legitimate monitor E isgiven by

.we adopt the eavesdropping non-outage probability as the performance metric. Hence, the main objective is to maximize the eavesdropping non-outage probability E{X} by jointly optimizing the receive and transmit beamforming vector wr, wt and the jamming power pd. Hence, the optimization problem can be formulated as

ADVANTAGES:

  • Efficient algorithms were proposed to obtain the optimal transmit/receive beamforming vectors.
  • Finally, low-complexity suboptimal beamforming schemes were proposed.
  • Analytical expressions were derived for the achievable eavesdropping non-outage probabilities of the suboptimal schemes
  • The findings suggest that adopting multiple-antenna tremendously improves the performance of the system.
  • Provides an attractive low-complexity solution for practical implementation.

 SYSTEM REQUIREMENTS:

HARDWARE REQUIREMENTS:

  • System : Pentium Dual Core.
  • Hard Disk : 120 GB.
  • Monitor : 15’’ LED
  • Input Devices : Keyboard, Mouse
  • Ram : 1GB

SOFTWARE REQUIREMENTS:

  • Operating system : Windows 7.
  • Coding Language : MATLAB
  • Tool : MATLAB R2013A

REFERENCE:

Caijun Zhong, Senior Member, IEEE, Xin Jiang, Student Member, IEEE, Fengzhong Qu, Senior Member, IEEE,and Zhaoyang Zhang, Member, IEEE, “Multi-antenna Wireless Legitimate SurveillanceSystems: Design and Performance Analysis”, IEEE Transactions on Wireless Communications, 2017.

 

Location Privacy Preservation in Database-driven Wireless Cognitive Networks through Encrypted Probabilistic Data Structures

Location Privacy Preservation in Database-driven Wireless Cognitive Networks through Encrypted Probabilistic Data Structures

 

ABSTRACT:

In this paper, we propose new location privacy preserving schemes for database-driven cognitive radio networks(CRNs) that protect secondary users’ (SUs) location privacy while allowing them to learn spectrum availability in their vicinity. Our schemes harness probabilistic set membership data structures to exploit the structured nature of spectrum databases(DBs) and SUs’ queries. This enables us to create a compact representation of DB that could be queried by SUs without having to share their location with DB, thus guaranteeing their location privacy. Our proposed schemes offer different cost performance characteristics. Our first scheme relies on a simple yet powerful two-party protocol that achieves unconditional security with a plausible communication overhead by making DB send a compacted version of its content to SU which needs only to query this data structure to learn spectrum availability.Our second scheme achieves significantly lower communication and computation overhead for SUs, but requires an additional architectural entity which receives the compacted version of the database and fetches the spectrum availability information inlieu of SUs to alleviate the overhead on the latter. We show that our schemes are secure, and also demonstrate that they offer significant advantages over existing alternatives for various performance and/or security metrics.

 OBJECTIVE:

In this paper, we propose two location privacy-preserving schemes for database-driven CRNs with different performance and architectural benefits. The first scheme, location privacy in database-driven CRNs (LPDB), provides optimal location privacy to SU s within DB’s coverage area by leveraging set membership data structures (used to test whether an element is a member of a set) to construct a compact version of DB. The second scheme, LPDB with two servers(LPDBQS), minimizes the overhead at SU ’s side at the cost of deploying an additional entity in the network.

INTRODUCTION:

 Cognitive radio networks (CRNs) have emerged as a key technology for addressing the problem of spectrum utilization inefficiency . CRNs allow unlicensed users, also referred to as secondary users (SU s), to access licensed frequency bands opportunistically, so long as doing so does notharm licensed users, also referred to as primary users (PUs).In order to enable SU s to identify vacant frequency bands, also called white spaces, the federal communications commission(FCC) has adopted two main approaches: spectrum sensing based approach and geo-location database-driven approach.In the sensing-based approach , SU s themselves sense the licensed channels to decide whether a channel is available prior to using it so as to avoid harming PUs. In the database driven approach, SU s rely on a geo-location database (DB)to obtain channel availability information. For this, SU s are required to be equipped with GPS devices so as to be able to query DB on a regular basis using their exact locations. Upon receipt of a query, DB returns to SU the list of available. This manuscript is an extension of , published in: Computer Networks and Information Security (WSCNIS), 2015 World Symposium on.channels in its vicinity, as well as the transmission parameters that are to be used by SU . This database-driven approach has advantages over the sensing-based approach. First, it pushes the responsibility and complexity of complying with spectrum policies to DB. Second, it eases the adoption of policy changes by limiting updates to just a handful number of databases, as opposed to updating large numbers of devices.

 EXISTING SYSTEM:

  1. Zhang, C. Fang, Y. Li, H. Zhu, and M. Dong, “Optimal strategies for defending location inference attack in database-driven crns,” in Communications (ICC), 2015 IEEE International Conference on.
  • Rely on this concept to make each SU query DB by sending a square cloak region that includes its actual location.
  1. Gao, H. Zhu, Y. Liu, M. Li, and Z. Cao, “Location privacy in database-driven cognitive radio networks: Attacks and countermeasures,”in INFOCOM, 2013 Proceedings IEEE. IEEE, 2013, pp. 2751–2759.
  • PIR, on the other hand, allows a client to obtain information from a database while preventing the database from learning which data is being retrieved.
  • approaches have used this approach

 PROPOSED SYSTEM:

Our proposed schemes offer various cost-performance trade-offs that can meet the requirements of different applications.We study these tradeoffs and show that high privacy and better performance for SU s’ can be achieved, but at the cost of deploying an additional architectural entity in the system.We show that our proposed schemes are secure and more efficient than their existing counterparts. In addition, we study the impact of system parameters on the performances of our

proposed schemes, and compare them against those obtained via existing approaches.

DESCRIPTION:

  1. Database-driven CRN Model

We first consider a CRN that consists of a set of SU sand a geo-location database (DB). SU s are assumed to be enabled with GPS and spectrum sensing capabilities, and to have access to DB to obtain spectrum availability information within its operation area. To learn about spectrum availability,a SU queries DB by including its location and its device characteristics. DB responds with a list of available channels at the specified location and a set of parameters for transmission over those channels. SU then selects and uses one of the returned channels. While using the channel, SU needs to recheck its availability on a daily basis or whenever it changes its location by 100 meters as mandated by PAWS . We then investigate incorporating a third entity to the network along with DB and SU s. This entity, referred to as query server (QS), has a dedicated high throughput link with DB. QS is used to guarantee computational location privacy while reducing the computational and communication overhead especially on SU s’ side.

  1. Security Model and Assumptions

DB and QS are assumed to be honest but curious. That is, DB and QS follow the protocol honestly but may try to infer information on the input of other parties beyond what the output of the protocol reveals. Specifically, our objective is to prevent these two entities from learning SU s’ location.Therefore, our security assumptions are as follows:

Security Assumption 1. DB and QS do not modify the integrity of their input. That is,

  • DB does not maliciously change SU ’s query’s content;
  • QS does not modify theinput that it receives from DB or SU .

Security Assumption 2. DB and QS do not collude witheach other to infer the location of SU s from their queries.

ADVANTAGES:

  • Two location privacy preserving schemes, called LPDB and LPDBQS.
  • To preserve the location privacy of SU s in database-driven CRNs.

SYSTEM REQUIREMENTS:

HARDWARE REQUIREMENTS:

  • System : Pentium Dual Core.
  • Hard Disk : 120 GB.
  • Monitor : 15’’ LED
  • Input Devices : Keyboard, Mouse
  • Ram : 1GB

SOFTWARE REQUIREMENTS:

  • Operating system : Windows 7.
  • Coding Language : MATLAB
  • Tool : MATLAB R2013A

REFERENCE:

Mohamed Grissa, Attila A. Yavuz, and Bechir Hamdaoui, “Location Privacy Preservation in Database-driven Wireless Cognitive Networks through Encrypted Probabilistic Data Structures”, IEEE Transactions on Cognitive Communications and Networking, 2017.

Joint Spectrum and Energy Efficiency in Device to Device Communication Enabled Wireless Networks

Joint Spectrum and Energy Efficiency in Device to Device Communication Enabled Wireless Networks

 

ABSTRACT:

This paper presents a joint spectrum and energyefficiency maximization mechanism for device to device (D2D)communication enabled wireless networks. Most approaches inthe literature, fail to take into account link heterogeneity in termsof their demands and the traffic they inject into the network.This paper presents a linear optimization formulation to allocatebandwidth to links, not only based on network topology, but alsobased on traffic injection patterns of devices and link demands.We derive bounds on the achievable spectrum efficiency. Theachieved spectrum efficiency and energy efficiency are furtherenhanced by deploying power control using M matrix theory.The proposed approach is shown to provide an improvementbetween 25% to up to 4 orders of magnitude in spectrumefficiency and between 25% to up to 5 orders of magnitude inenergy efficiency compared to existing mechanisms, depending onthe network topology and traffic injection patterns of the nodes.

 OBJECTIVE:

        To provide a mechanism to maximize achievedspectrum and energy efficiency taking into account, (i) thepower/energy limitations of every device, (ii) the limitedavailability of bandwidth in the system, (iii) the traffic injectedby each device (and in turn, on each link) and (iv) the demands of system on individual links.

 INTRODUCTION:

          Next generation 5G wireless and dynamic spectrum access (DSA) networks provide multiple types of services to a large number of users with many devices competingfor a limited available bandwidth Also, multiple servicesmay result in large energy consumption. In order to supportenergy conservation, Device-to-Device (D2D) communicationis supported in 5G and DSA networks where in, direct communication between two mobile users ispossible without data flow into a centralized base station. D2Dcommunications is widely applied in networks using Internetof Things which, in turn, is deployed in a variety ofsystems including sensor networks air quality systemsemergency services health care systems smartcities water quality measurements smart grids security systems and military environments Sincemost D2D networks use low power devices, energy efficiencyis a very important requirement. Further, these devices maybe placed in a hostile environment where coverageand available bandwidth may be very poor.This makes jointspectrum and energy efficiency mechanisms an indispensable
mandate for D2D communications in 5G networks.

 EXISTING SYSTEM:

  1. Sathyamoorthy, E. Ngai, X. Hu, and V. C. M. Leung, “Energy
    efficiency as an orchestration service for mobile Internet of things,” IEEE
    Intl. Conf. on Cloud Computing Technol. and Sc.
    , Nov. 2015
    .

Cloudorchestration architecture was used to decrease energy consumption in smart phones.

  1. Xiao, D. Feng, Y. Yuan-Wu, G. Y. Li, L. Guo, and S. Li, “Optimal mobile association in device-to-device-enabled heterogeneous networks,”
    IEEE Vehic. Technol. Conf. (VTC’2015), Sep. 2015.

 Xiao et al developed aframework on joint mobile association and transmission modeswitching between the direct and the D2D relay modes to improve spectrum and energy efficiency.

 DRAWBACKS:

  • The system has limited bandwidth available.
  • All pairsof communicating nodes must share the available bandwidth.
  • Each node injects a different amount of traffic into thenetwork.

PROPOSED SYSTEM:

This paper presents a joint spectrum and energyefficiency based on traffic pattern, demands of individual linksand consuming minimal energy.

DESCRIPTION:

The key contribution of this paper is a joint spectrum andenergy efficient solution in D2D networks that take into account (i) network topology, (ii) traffic patterns, (iii) individuallink demands and power transmission capacity of individualdevices. One means to reduce energy consumption (i.e., increaseenergy efficiency) is by all devices transmitting at power lessthan their maximum transmission power capacity

 ADVANTAGES:

  • Provide an improvement between 25% to up to 4 orders of magnitude in spectrum efficiency and between 25% to up to 5 orders of magnitude in energy efficiency compared to existing mechanisms.
  • It not only reuse bandwidth more efficiently and save energy, but also to ensure that the quality of communication.

SYSTEM REQUIREMENTS:

HARDWARE REQUIREMENTS:

  • System : Pentium Dual Core.
  • Hard Disk : 120 GB.
  • Monitor : 15’’ LED
  • Input Devices : Keyboard, Mouse
  • Ram : 1GB

SOFTWARE REQUIREMENTS:

  • Operating system : Windows 7.
  • Coding Language : MATLAB
  • Tool : MATLAB R2013A

REFERENCE:

  1. Alnakhli, S. Anand and R. Chandramouli, “Joint Spectrum and Energy Efficiency in Device to Device Communication Enabled Wireless Networks”, IEEE Transactions on Cognitive Communications and Networking, 2017.

Joint Rate Control and Scheduling for Real-Time Wireless Networks

Joint Rate Control and Scheduling for Real-Time Wireless Networks

ABSTRACT:

This paper studies wireless networks with multiple real-time flows that have stringent requirements on both per-packet delay and long-term average delivery ratio. Each flow dynamically adjusts its traffic load based on its observation of network status. When the requirements of per-packet delay and delivery ratio are satisfied, each flow obtains some utility based on its traffic load. We aim to design joint rate control and scheduling policies that maximize the total utility in the system. We first show that the problem of maximizing total utility can be formulated as a submodular optimization problem with exponentially many constraints. We then propose two simple distributed policies that require almost no coordination between different entities in the network. The total utilities under these two policies can be made arbitrarily close to the theoretical upper-bound. Extensive simulations also show that they achieve much better performance than state-of the- art policies.

OBJECTIVE:

We aim to design joint rate control and scheduling policies that maximize the total utility in the system. We first show that the problem of maximizing total utility can be formulated as a submodular optimization problem with exponentially many constraints. We then propose two simple distributed olicies that require almost no coordination between different entities in the network. The total utilities under these two policies can be made arbitrarily close to the theoretical upper-bound. Extensive simulations also show that they achieve much better performance than state-ofthe- art policies.


INTRODUCTION:

The demands for real-time applications such as video streaming and online gaming in wireless network have been increasing drastically over the decade. According

to a recent Cisco report , mobile video traffic will increase eleven-fold between 2015 and 2020, and account for three quarters of the overall mobile traffic by 2020. These applications can lead to severe network congestion in wireless networks. Further, real-time applications have some unique features, such as hard per-packet delay requirement and delivery ratio requirement, that separate them from traditional non-real-time applications. Directly employing standard congestion control and resource allocation policies without explicitly addressing these features can thus lead to poor network performance. In this paper, we study wireless systems that consist of multiple real-time flows where each flow can dynamically adjust its traffic load. Each flow has a hard per-packet delay requirement to meet real-time constraint, as well as a packet delivery ratio requirement to ensure data integrity. When both delay and delivery ratio requirements are satisfied, each flow obtains some utility based on its traffic load.

 

EXISTING SYSTEM:

KELLY, F. Charging and rate control for elastic traffic, 1997.

  • The study of controlling networks using an optimization approach has continued for over two decades.

LIN, X., AND SHROFF, N. Joint rate control and scheduling in multihop wireless networks. In in Proceedings of IEEE Conference on Decision and Control (Dec. 2004).

  • Proposed a joint rate control and scheduling algorithm for non real-time applications in multi-hop wireless networks.

PROPOSED SYSTEM:

We aim to design joint rate control and scheduling policies that achieve the maximum system-wide total utility. We propose an analytical model that incorporates the aforementioned features of real-time applications and the stochastic nature of wireless transmissions. The problem of maximizing total utility can then be modeled as a submodular optimization problem with exponentially many constraints. While there exists polynomialtime algorithms that solve the submodular optimization problem, they still incur high computational complexity and rely on centralized algorithms.

 

DESCRIPTION:

Consider a wireless system with one access point (AP) serving M wireless clients. Each client is associated with a downlink real-time flow that can adaptively adjust its data rate based on network congestion. Time is slotted and indexed as t = 1, 2, . . . , where the duration of a time slot is chosen to be the amount of time needed to transmit a data packet and an ACK. Wireless transmissions can be unreliable, and we say that each transmission for client m is successful with probability pm. By requiring ACKs for all transmissions, the AP has the feedback information about

whether a transmission is successful, and may retransmit the same packet if previous transmissions fail. In the downlink scenario, sources of real-time flows have reliable and wired connections to the AP, and can therefore obtain feedback information, such as channel state and whether a transmission is successful from the AP.

A CENTRALIZED GREEDY ALGORITHM

we propose a centralized greedy algorithm that solves problem optimally using techniques developed for submodular optimization.:

.

DISTRIBUTED POLICIES FOR JOINT RATE CONTROL AND SCHEDULING

we propose two joint rate control and scheduling policies. One is a fully distributed policy that requires almost no information exchange between the AP and clients. The other policy is similar to the first one, but employs a global variable to achieve a better convergence rate.

 

ADVANTAGES:

  • Two asymptotically optimal policies, both of which have very low complexity.
  • The performance of our policies is further evaluated via ns-2 simulation.
  • Simulation results show that our policies achieve better performance than three other competing policies.

SYSTEM REQUIREMENTS:

HARDWARE REQUIREMENTS:

 

  • System : Pentium Dual Core.
  • Hard Disk : 120 GB.
  • Monitor : 15’’ LED
  • Input Devices : Keyboard, Mouse
  • Ram : 1gb

SOFTWARE REQUIREMENTS: 

  • Operating system : Windows 7.
  • Coding Language : MATLAB
  • Tool : MATLAB R2013A

REFERENCE:

Shuai Zuo, I-Hong Hou, Tie Liu , Ananthram Swami , and Prithwish Basu, “Joint Rate Control and Scheduling for Real-Time Wireless Networks”, IEEE Transactions on Wireless Communications, 2017.

Huffman Coding Based Adaptive Spatial Modulation

Huffman Coding Based Adaptive Spatial Modulation

Huffman Coding Based Adaptive Spatial Modulation

 

ABSTRACT:

Antenna switch enables multiple antennas to share a common RF chain. It also offers an additional spatial dimension,i.e., antenna index, that can be utilized for data transmission via both signal space and spatial dimension. In this paper, we propose a Huffman coding based adaptive spatial modulation that generalizes both conventional spatial modulation and transmit antenna selection. Through Huffman coding, i.e., designing variable length prefix codes, the transmit antennas can be activated with different probabilities. When the input signal is Gaussian distributed, the optimal antenna activation probability is derived through optimizing channel capacity. To make the optimization tractable, closed form upper bound and lower bound are derived as the effective approximations of channel capacity. When the input is discrete QAM signal, the optimal antenna activation probability is derived through minimizing symbol error rate.Numerical results show that the proposed adaptive transmission offers considerable performance improvement over conventional spatial modulation and transmit antenna selection.

OBJECTIVE:

  • In this paper, we propose a Huffman coding based adaptive spatial modulation that generalizes both conventional spatial modulation and transmit antenna selection. Through Huffman coding, i.e., designing variable length prefix codes, the transmit antennas can be activated with different probabilities.
  • When the input signal is Gaussian distributed, the optimal antenna activation probability is derived through optimizing channel capacity. To make the optimization tractable, closed form upper bound and lower bound are derived as the effective approximations of channel capacity.
  • When the input is discrete QAM signal, the optimal antenna activation probability is derived through minimizing symbol error rate. Numerical results show that the proposed adaptive transmission offers considerable performance improvement over conventional spatial modulation and transmit antenna selection.

 INTRODUCTION:

Multiple-input multiple-output (MIMO) is a proven technique that can improve the spectral efficiency of a communication system . The main limitation of using multiple antennas is the high cost of radio frequency (RF) chain.A simple solution to reduce the high hardware cost is the utilization of a single RF front-end in the MIMO system.Spatial modulation is a dominant transmission scheme for single RF chain MIMO . In spatial modulation, information bits are split into two parts. The first part is mapped to the signal symbols (e.g. Gaussian code, QAM constellation), and the other part is mapped to the spatial symbols (antenna index). In spatial modulation, Ntransmit antennas are equally probable to be activated to transmit

signal symbols, thus a maximum of log2 Ntbits additionalinformation can be obtained. However, the channel qualitiesof the Ntpossible links between the receiver and the activatedtransmit antennas are different. Mutual information derived byending signal symbol over the weak link is evidently worsethan that of the strong link, which makes the performance ofspatial modulation depend on favorable propagation conditions.

 EXISTING SYSTEM:

  1. Guan, Y. Xiao, Y. Cai, and W. Yang, “On the mutual information and precoding for spatial modulation with finite alphabet,” IEEE Wireless Commun. Lett., vol. 2, no. 4, pp. 383-386, Aug. 2013.
  • A precoding method to maximize the mutual information of multiple-input single-output (MISO) spatial modulation is proposed.
  1. Maleki, H. R. Bahrami, S. Beygi, M. Kafasha, and N. H. Tran, “Spacemodulation with CSI: Constellation design and performance evaluation,”IEEE Trans. Veh. Technol., vol. 62, no. 4, pp. 1623-1634, May 2013.
  • A heuristic diagonal precoder design method is proposed for the space shift keying a simplified spatial modulation, that jointly allocates transmit power and optimizes phase rotation.

 PROPOSED SYSTEM:

In this paper, we propose a Huffman coding based adaptive spatial modulation that can generalize both transmit antenna selection and spatial modulation. With Huffman mapping,transmitter can adjust the activation probability of each transmit antenna according to the receiver-side feedback. When the input signal is Gaussian distributed, the optimal antenna activation probability is derived through optimizing channel capacity. The closed form upper bound and lower bound for

channel capacity are determined, which are good approximations of the channel capacity.

BLOCK DIAGRAM:

Huffman Coding Based Adaptive SpatialModulation

DESCRIPTION:

Consider a MIMO system with Ntransmit and Nr receive antennas as shown in Fig. 1. At transmitter side, there is merely a single RF chain connected with Ntransmit antennas through an antenna switch. At receiver side, each receive antenna has its corresponding RF chain. The received signals can be represented as the additive white Gaussian noise (AWGN) following circularly symmetric complex Gaussian distribution, ρ is SNR and the transmitted signal x is

The data stream is split into two independent streams, referred to as signal information and antenna information. Signal information is conveyed via the signal s, and antenna information is mapped to the spatial symbol r (antenna index). In each time slot, the signal s is conveyed by the active transmit antenna that is selected according to the antenna information.We denote the probability of selecting the ith  transmit antenna as

The objective of this paper is to solve the two key problems,i.e., 1) How to design flexible and feasible transmissionschemes for spatial modulation given p; 2) How to find theoptimal p.

 ADVANTAGES:

  • Performance improvement over both conventional spatial modulation and transmit antenna selection.
  • A unified adaptive transmission scheme for single-RF chain
  • Transmitter can activate each transmit antenna with different probabilities so as to optimize the performance.

SYSTEM REQUIREMENTS:

HARDWARE REQUIREMENTS:

  • System : Pentium Dual Core.
  • Hard Disk : 120 GB.
  • Monitor : 15’’ LED
  • Input Devices : Keyboard, Mouse
  • Ram : 1GB

SOFTWARE REQUIREMENTS: 

  • Operating system : Windows 7.
  • Coding Language : MATLAB
  • Tool : MATLAB R2013A

REFERENCE:

Wei Wang, Student Member, IEEE, and Wei Zhang, Fellow, IEEE, “Huffman Coding Based Adaptive Spatial Modulation”, IEEE Transactions on Wireless Communications, 2017.