A low computational complexity V-BLAST/STBC detection mechanism in MIMO system

Abstract

The idea of multiple antenna arrays has evolved into multiple-input multiple-output (MIMO) system, which provides transmit and receive diversities. It increases robustness of the effect of multipath fading in wireless channels, besides yielding higher capacity, spectral efficiency and better bit error rate (BER) performance. The spatial diversity gain is obtained by transmitting or receiving multiple copies of a signal through different antennas to combat fading and improves the system BER performance. However, the computational complexity of MIMO system is inevitably increased. Space-time coding (STC) technique such as Alamouti's space-time block code (STBC) that combines coding, modulation and signal processing has been used to achieve spatial diversity. Vertical Bell Laboratories Layered Space-Time (V-BLAST) uses antenna arrays at both the transmitter and receiver to achieve spatial multiplexing gain. Independent data streams that share both frequency bands and time slots are transmitted from multiple antennas and jointly detected at the receiver. The theoretical capacity of V-BLAST increases linearly with the number of antennas in rich scattering environments. It's well-known that maximization of spatial diversity gain leads to degradation of spatial multiplexing gain or vice versa. In order to achieve spatial multiplexing and diversity gains simultaneously, the V-BLAST/STBC scheme has been introduced. This hybrid scheme increases MIMO system capacity and maintains reliable BER performance at the same time. However, both V-BLAST and STBC layers, in this hybid scheme, assume each other as an interferer. Thus, the symbols must be decoded with a suitable detection mechanism. In this paper, a new low complexity detection mechanism for V-BLAST/ STBC scheme based on QR decomposition, denoted as low complexity QR (LC-QR) decomposition, is presented. The performance of the proposed LC-QR decomposition detection mechanism in V-BLAST/STBC transceiver scheme is compared with other detection mechanisms such as ZF, MMSE and QR decomposition. It is shown that the BER performance in V-BLAST/STBC scheme is better than V-BLAST scheme while its system capacity is higher than orthogonal STBC scheme when the LC-QR decomposition detection mechanism is exploited. Moreover, the computational complexity of proposed LC-QR decomposition mechanism is significantly lower than other abovementioned detection mechanisms.

Massive MIMO Detectors Based on Deep Learning, Stair Matrix, and Approximate Matrix Inversion Methods

“…Gaussian elimination method is provided by O(ab 2 ) for an a×b matrix [58]. In the ZF V-BLAST algorithm, it is required to obtain the matrix inverse of H H H H H H H for the ZF techniques.…”

Integrated Spatial Modulation and STBC-VBLAST Design toward Efficient MIMO Transmission

“…According to [22], the number of complex arithmetic operations, including complex multiplications and additions, is used to measure complexity. In general, the total complex arithmetic operations required of MMSE STBC-VBLAST without TPA number 8(M − 1) 3 + 4(8N − 1)(M − 1) 2 + 4N(M − 1).…”

“…A new TPA scheme, intergrated into the original STBC-VBLAST structure, is proposed to improve the BER performance of STBC-VBLAST. A specific class of STBC-VBLAST systems with TPA, in which two of the antennas transmit Alamouti's STBC and the others transmit independent data streams [22], was chosen as the target to exploit. Simulation results and performance analysis indicate that the TPA scheme can significantly enhance the BER performance of STBC-VBLAST systems in terms of maximum-likelihood (ML), MMSE and ZF with a negligible implementation cost.…”

Privacy-Enhancing Security Protocol in LTE Initial Attack

“…The "location update" process is the one that receives personal profile information from HSS after registering the location, and the "EPS session establishment" process is the one that allocates network resources, so that the users can be provided with the services [20,21].…”