Performance Evaluation Of A Layered Space-time Structure For Mimo Systems

MIMO systems are an appealing candidate for emerging fourth-generation wireless networks duernto their potential to exploit space diversity for increasing conveyed throughput without wastingrnbandwidth and power resources. Particularly, layered space-time architecture (LST) proposed byrnFoschini, is a technique to achieve a significant fraction of the theoretical capacity with arnreasonable implementation complexity. It is based on signal processing and conventional onerndimensional coding, which includes vertical BLAST (Bell Laboratories Layered Space Time)rnand diagonal BLAST. BLAST accomplishes this by splitting a single user’s data stream intornmultiple sub-streams and using an array of transmitter antennas to simultaneously launch thernparallel sub-streams. All sub-streams are transmitted in the same frequency band, so spectrum isrnused very efficiently. Since the user’s data is being sent in parallel over multiple antennas, therneffective transmission rate is increased roughly in proportion to the number of antenna elementsrnused. rnIn this thesis, we focus on the performance evaluation of a layered space-time structure forrnMIMO systems under Rayleigh fading condition. Firstly, we throughly understand the differentrnlayered space-time architectures and investigate the performance of general V-BLASTrnarchitecture with Maximum Likelihood (ML), Zero-Forcing (ZF), Minimum Mean-Square Errorrn(MMSE), the Successive Interference Cancellation (SIC) and the Ordered SuccessivernInterference Cancellation (OSIC) detectors for 2 × antenna arrangement. Here, in addition tornperformance (BER), the different detection algorithms are evaluated in terms of computationalrncomplexity. From the results, we have seen that the maximum-likelihood (ML) detector isrnoptimum in the sense of achieving the minimum error probability. Unfortunately, the complexityrnof the ML detector is exponential in the constellation size and the dimensions of the system. But,rnby using the SIC & OSIC detectors, we approach the performance of the ML detector with lowerrncomputational complexity. It is also shown that the average performance is improved when thernnumber of receive antenna increases. Finallly we understand and evaluate performance boundrntrends of Rate Compatible Punctured Convolutional (RCPC) codes and investigate the unequalrnerror protection capabilities of rate compatible punctured convolutional codes (RCPC codes)rnwhen used together with V-BLAST MIMO systems for a mother code rate of 1/4. The

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