Analysis of Improved Square-Root Algorithm Based on Efficient Inverse Cholesky Factorization for V-blast MIMO Wireless Communications
S. A. Hariprasad · 2012
Vertical Bell Laboratories Layered Space time (V-BLAST) detection schemes are widely used in time critical application involving high speed packet transfer using MIMO for 3GPP and 3GPP-2 standards. As the number of transmitting and receiving antennas is increased, employing efficient square root algorithm yields high computational cost due to the inefficient utilization of orthogonal or unitary transformations and discarding intermediate results without any usage. Reduction in the computational cost is achieved by improved square root algorithm which utilizes intermediate results that were discarded without any usage in the original square-root algorithm. Further reduction in computational cost can be achieved by employing a fast algorithm for inverse Cholesky factorization used to compute a triangular square-root of the estimation error covariance matrix which is then applied to improved square-root algorithm. This paper compares the performance between the improved square root algorithm with minimum mean square error (MMSE) filter and an Improved Square-Root Algorithm Based on Efficient Inverse Cholesky Factorization with MMSE filter when subjected to multi-media application for various numbers of transmitting and receiving antennas with varying SNR. Performance parameters considered include bit error rate (BER), symbol error rate (SER), peak signal-to- noise ratio (PSNR), number of number of floating point operations (FLOPS), Time required for detection. The number of floating point operation (FLOPS) required for detection for improved square root algorithm based on efficient inverse cholesky factorization with MMSE for 16 transmitting and 16 receiving antennas is 0.6 x 10 6 , a reduction of 2.9x10 6 , 4.2x10 6 , 5.4x10 6 and 5.6x10 6