4G Communication Resource Analysis with Adaptive Physical Layer Technique

Transcription

1 International Journal of Engineering Trends and Technology (IJETT) Volue 33 uber - March 206 4G Counication Resource Analysis with Adaptive Physical Layer Technique Mubinul Haque, Dr. Md. Abu Bakar Siddiqui 2 Dept. of Electrical and Electronic Engineering Aerican International University Bangladesh (AIUB), Dhaka, Bangladesh Abstract- For telecounication services the draatic shift in the arket has been ade in beginning of 2st century. In present days, counication network is the key challenges to integrate nuerous services, convey the additional data as expeditiously as doable through liited bandwidth and providing high inforation data rates. For 4G counication systes 3GPP introduced two features. Higher Order Modulation and Multiple Input Multiple Output (MIMO) in OFDM syste but one liiting issue in ipleenting high-speed wireless systes is the ipairent associated with analog processing due to coponent iperfections. uerous works have discussed in LTE perforance; however, ost have been restricted to liited scenarios. For LTE MIMO-OFDM syste is sensitive to frequency errors, causing inter carrier interference (ICI) aong subcarriers and phase noise. This analysis Investigate to the axiu data throughput under different conditions and scenarios which will provide in depth perforance study in LTE physical layer s characteristics under 3GPP standard in release 0. As perforance etrics date throughput, Bit Error Rate (BER) are evaluated in ters of Signal to oise ratio (SR) for 2 copletely different Multi- Input Multi-Output (MIMO) schees, Which is outlined in LTE standard under different cobination of digital odulation schees. Syste for Mobile (GSM) and IS-95. The eergence of 3G systes cae to the scene when IMT-2000 (International Mobile for Telecounications-2000) [3] was developed in id-980 at ITU (International Telecounication Union). Within the year 2002 outstanding systes were developed beneath IMT- 2000, WCDMA/UMTS (Wideband CDMA/Universal Mobile Telecounication Syste) and CDMA [4]. each of the higher than have evolved in to questionable 3.5G.At present, the Third Generation Partnership Project long ter Evolution (3GPP LTE) is taken into account because the path to the next generation of cellular syste [5]. II. SYSTEM DESCRIPTIO AD MODELIG MIMO-OFDM is being considered the ost proising ultiplexing techniques to support the 4G counication syste because of its bandwidth efficiency perforance. The effects of Inter Sybol interference (ISI) is very less than the syste copare to the other ultiplexing techniques. But Unfortunately OFDM is very sensitive to the synchronization errors such as Carrier frequency offset (CFO), phase noise. A. MIMO-OFDM Syste Model Keywords LTE, Data Throughput, PHY, phase noise, MIMO-OFDM, Code word Bit Error Rate (CBER). I. ITRODUCTIO Mobile wireless counication provides evolutionary ethods for individuals to counicate, because it blends counication with quality. In a very short span of tie outstanding achieveents and advanceents have already been recorded within the story of wireless counications. The Evolution of wireless counication has already began its fourth Generation, [].G, The first generation of obile wireless counication used analog counication techniques, that were designed priarily on odulation (FM) and frequency division ultiple access (FDMA) [2]. Electronic counication techniques eerged fro (2G) that were designed on tie division ultiple access (TDMA); the foreost wide accepted systes of 2nd generation were Global Fig. OFDM Syste Model (Reciver Section) In fig., Consider the th sybol of an - sub carrier OFDM syste in presence of noralized CFO (ε), phase noise φ(n) and tiing jitter (ξ). B. Carreir Frequency Offset For carrier frequency offset the absolute value of is fε, an integer ultiple or a fraction of Δf. ow if the sub carrier spacing Δf noralized by fε then it noralized CFO. The channel is expressed as δ is an ISS: Page 2

2 International Journal of Engineering Trends and Technology (IJETT) Volue 33 uber - March 206 integer and є =<0.5 If the Carrier frequency offset occurs then the sybol transitted on a certain sub carrier k, will shift to another sub carrier ks = k+δ. C. Phase oise Phase noise φ (n) can be generated at both transitter and receiver side. It can be odeled as The transfer function of the Rayleigh fading H ( ) k is the transfer function of the Rayleigh fading channel at the frequency of the kth carrier and w ( ) n is the coplex envelope of the AWG with zero ean and variance ζ2. Assuing ( n ) is very sall so, () g g n n g g i 0 u i c u T i i 0 i 0 (2) u iand g g (3) Where c and T are defined by Respectively. For cyclic prefix g is the length and u (i) denotes Gaussian rando variables having zero ean and variance of ζu2. There is another noise that is introduced by the channel. It is Additive White Gaussian oise (AWG). This noise added to the essage signal and its PDF follows Gaussian s distribution function. D. Calculation of SR and BER In fig the transitted OFDM signal for the th sybol is given by the point coplex odulation sequence x n X k e (4) k 0 2 j nk Where n is ranges fro 0 to +g- After passing through a Rayleigh fading channel and LO, the received signal ipaired by AWG and P can be odeled as- 2 j n k j n k 0 y n X k H k e e w n (5) Where (6) n g i g n u i y n s n e w n j n j n e j n (8) Where S (k), Θ (k) and W (k) are the DFT responses of s (n), ( n ) and w ( ) n respectively. E. Downlink OFDM Paraeters The basic technology of LTE is Orthogonal Frequency Division Multiplexing (OFDM), which is used in the downlink transission schee because of its ulticarrier odulation. This provides a large syste bandwidth into ultiple narrowband sub-carriers and occurs each sub-carrier nearly flat fading. Cyclicprefix itigates inter sybol interference in a tie dispersive channel. For OFDM syste it has several basic paraeter such as the sub-carrier spacing Δf, the nuber of the FFT size ( ), subcarriers ( ), and the cyclic prefix length ( ). As shown in Table., 5 khz used for sub-carrier spacing and the latter three paraeters are decided by the syste bandwidth (BW). It has soe other paraeter such as, the sapling frequency s f and the nuber of OFDM sybols in a slot ( ) [6]. BW(MH z) f syb cp TABLE I Downlink OFDM paraeters [6] KHz sc f s 7/6 (noral/extended CP) syb cp sc (7) ISS: Page 22

3 International Journal of Engineering Trends and Technology (IJETT) Volue 33 uber - March 206 F. MIMO Receiver For Channel estiation, least-squares estiation has used averaging over a sub frae for noise reduction to the reference signals and the data eleent of the subcarriers liner interpolation is using. III. TABLE II Siulation paraeters Paraeter Value Channel Bandwidth 5 MHz Duplex Mode FDD Channel Type EPA 5MHz FEC Coding Turbo Coding /3 Modulation QPSK, 6-QAM, 64- QAM Subcarrier Spacing 5 KHz Code Rate 0.75 Antenna Diversity 4X4 and 3X6 MIMO SIMULATIO AD RESULT AALYSIS Fig. 2 Perforance of QAM using AWG and Rayleigh channel for 4x4 MIMO. The above figure depicts BER for 6-QAM, 64-QAM odulation schee with OFDM in AWG and Rayleigh channels without diversity. For the chosen setup paraeters, it evaluates the perforance of 6- QAM OFDM using AWG is better than Rayleigh channel because AWG channel has a sipler odel without experiencing any fading. The perforance of LTE physical layer was analyzed and evaluated at different noise levels. Various BER vs SR, data throughput vs SR plots are presented for different essential odulation. For MIMO-OFDM fading channel Perforance analysis results are provided based on FDD operation. Our results are based on MATLAB siulations for which the relevant paraeters are suarized in Table 2. For better understanding of the LTE perforance, results are classified as two ain categories: 5 MHz of syste bandwidth utilizing 4x4 MIMO, and 5 MHz of syste bandwidth utilizing 3x6 MIMO in downlink. A. Analysis of Different Modulation with Fading Chanel in LTE syste In this siulation part a nuber of siulation scenarios have been conducted to investigate the ipact of higher order odulation along with the effects of using MIMO techniques in AWG and Rayleigh Channels. BER is evaluated as a function of SR in all siulation Scenarios. The following scenarios are investigated: Perforance of QPSK and M-QAM Using AWG and Rayleigh channel for 4x4 MIMO Techniques. Perforance of QPSK and M-QAM Using AWG Rayleigh and channel for 3x6 MIMO Techniques. Fig. 3 Perforance of QPSK and QAM using AWG and Rayleigh channel for 3x6 MIMO Above figure indicates that the bit error rate of QPSK is saller as copared to 6 or 64 QAM. In the above figure, LTE operates in Multi Path Rayleigh fading channel along with different MIMO Configurations, changing the antenna pattern in both side respect to transitter and receiver antennas when using M-QAM OFDM syste. It can be seen fro the above figure, as the nubers of antennas are increased on the transitter side or the receiver side, the bit error rate becoes lower. Initially, Fig.2 and fig.3 analyzed with two code word for codebook index as Specification of 3GPP release which are QPSK, M-QAM. The two MIMO techniques (4X4 and 3X6) are applied. It has seen that the lower odulation schee gives better perforance with less SR. Furtherore, the perfect selection of the Adaptive odulation (AMC) ode ISS: Page 23

4 International Journal of Engineering Trends and Technology (IJETT) Volue 33 uber - March 206 has ade in such a way that guarantees a BER below a given target BER. In 64-QAM odulation, relatively high SR was observed for the good BER perforance. In fact, in 3x6 MIMO configuration syste the BER of 0^-3 was achieved with 28 db, however the sae value of BER is with only 24 db in the 4x4 diversity schee. So it has proven that 4 db SR gain is clearly increasing in 3x6 diversity schee. This has happened due to the fact of enhancing coplexities for higher order odulation schees. Moreover, the Euclidean distances between the sybols decrease for higher order QAM, hence higher order QAM which leads to increase BER even for the little occurrence of noise. OFDM and MIMO are ipleented where we utilized the Transit Diversity (TD) for the LTE transission. C. Perforance Analysis of Data Throughput Vs SR configuration is shown in Fig.4. It can observed that as the SR increase the data throughput increase and it reaches its axiu at alost 24 db SR as in BER and 30 Mbps capacity can be achieved in the PDSCH channel. For achieving axiu capacity high order odulation high SR required. The data throughput of 3x6 MIMO configurations is shown in Fig.5 and it shows for axiu data throughput of 74 Mbps can be achieved at SR 28 db when the eb uses the bandwidth of 5 MHz for transferring data to the UE in the PDSCH channel by using 0.75 code rate with 64-QAM. IV. AALYSIS OF OISE I DIFFERET MIMO SYSTEM A. Perforance Analysis for 3x6, 4x4, 2x2 Transission Syste Fig. 4 4X4 MIMO Downlink Throughput in 5 MHz bandwidth. Fig 6 Analysis of the SR Vs BER for 3x6, 4x4, and 2x2 transission Fig. 5 3X6 MIMO Downlink Throughput in 5 MHz bandwidth. Fig 4 and fig 5 shows data throughput vs SR in fixed 5 MHz channel bandwidth for downlink syste with two MIMO syste.fig.4 and fig. 5 for FDD operation based on entioned paraeters in Table.2.The data throughput of 4x4 MIMO Fig 7 Analysis of the SR Vs BER graph for different value of noises (Tx=3; Rx=6) Fig 6 is for BER vs SR graph for 3 different MIMO syste configuration and analysis that which configuration gives batter perforance for phase noise.it has been seen that 3x6 antenna syste gives ISS: Page 24

5 International Journal of Engineering Trends and Technology (IJETT) Volue 33 uber - March 206 better perforance so using that configuration phase noise has been varied with different variances of phase noise value which has been seen in fig 7. C. Analysis for SR Vs BER for 4x8, 3x6, 4x4, 2x2 Transission Fig. 0 Analysis of the receiver sensitivity graphs are plotted for different value of noises Fig 0 shows that Receiver sensitivity graph that shows if nuber of transission antenna increasing then signal to noise ratio is decreasing. Fig 8 Analysis of the SR Vs BER for 4x8,3x6, 4x4, and 2x2 transission Fig:8 is for 4x8 with other three different MIMO antenna syste which represents BER vs SR and phase noise analyzed for 4x8 syste with different phase values And it has been seen that 4x8 gives less perforance then 3x6 antenna. In 3x6 antenna configuration we can archived 7 db SR gain where 4x8 syste 9 db, eans 2 db SR increased. Other antenna syste. V. DISCUSSIOS AD COCLUSIOS In this thesis paper I have been analyzing the perforance of LTE (Release 0). The analysis has targeted on the ost feature involved in the downlink, just like the user ultiplexing, adaptive odulation and support for ultiple antennas through MIMO syste. The present results in this paper show that, 3x6 MIMO-OFDM syste for LTE can achieve 74 Mbps of downlink data throughput for PDSCH and 0-3 BER when using 64-QAM and phase noise also analyzed with that configuration.it has clearly shows that for LTE downlink syste, if 3x6 MIMO antenna configuration will be used then 74 Mbps data capacity can achievable with lower phase noise. ACKOWLEDGMET Fig. 9 Analysis of the SR Vs BER graph for different value of noises (Tx=4; Rx=8) Fig 9 for different value of noises. We can observed that, for 4x8 antenna configuration syste the SR level vary fro 5.5 to 9 db. Which is soe grater then 3x6 syste. I would like to express y special thanks to y supervisor Dr. Md. Abu Bakar Siddiqui, Assistant Professor, Faculty of Engineering, AIUB for giving us enorous support, otivation and invaluable advises regarding this thesis. REFERECES [] Diva, J. Sengupta, K. Ait and Y. Liu. (200) Evolution of Mobile Wireless Counication etworks: G to 4G. International Journal of Electronics and Counication Technology (IJECT) Vol. Issue.p [2] H.G. Myung (2007) Single Carrier Orthogonal Multiple Access Technique for Broad-band Wireless Counication.PhD Dissertation, Polytechnic University, January ISS: Page 25

6 International Journal of Engineering Trends and Technology (IJETT) Volue 33 uber - March 206 [3] J.Berkann(2008) On 3G LTE Terinal Ipleentation Standard, Algoriths, Coplexities and Challenges. IWCMC 2008 Mobile Coputing Syposiu, [4] ETSI TS 36 2 V0.0.0 (20-0) LTE; Technical Specification. Evolved Universal Terrestrial Radio Access (E-UTRA); Physical channels and odulation (3GPP TS 36.2 version Release 0). [5] I. Toufik, M. Baker, S. Sesia (20) LTE The UMTS Long Ter Evolution Fro Theory To Practice. Second Edition Wiley Publication 20. [6] 3GPP Technical Specification Group Radio Access etwork; Evolved Universal Terrestrial Radio Access (EUTRA);User Equipent (UE) radio access capabilities (Release0), 3GPP TS v0.0.0 (200-2). University (AIUB). He joined AIUB in May 203. He copleted his M.Sc in 987 fro Technical University, Sofia, Bulgaria. He also obtained PhD fro the sae university in 99 on Telecounication area. During his PhD study, he ade invention on line coding (Balanced 3B2T). Before his joining to AIUB, he held various technical positions in telecounications corporate organizations in Bangladesh. His research interest includes 4G obile counication, digital broadcasting syste and VLSI circuit design. Mubinul Haque has copleted his Bachelor of Science in Electrical and Electronics Engineering (EEE) fro Aerican International University-Bangladesh (AIUB) in 203.After the copletion of his BSc progra currently he is doing Master of Science in Electrical and Electronics Engineering (M.Sc in EEE) in Aerican International University-Bangladesh (AIUB). His current research interests include etworking,wireless Counication, Microwave syste,. He is also an Assosiate Meber of The Institution of Engineers Bangladesg (IEB). Dr. Md. Abu Bakar Siddiqui has been serving as an assistant professor in the Departent of Electrical and Electronic Engineering at Aerican International ISS: Page 26