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| Optimal Transmit Power Allocation for Asynchronous V-BLAST System Using Zero-Forcing Detecting |
| Guan Lu; Tang You-xi; Shao Shi-hai; Deng Kai |
| National Key Lab. of Communication, University of Electronic Science and Technology of China, Chengdu 610054, China |
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Abstract Since different delay offsets are applied to the spatially multiplexed data streams of asynchronous vertical Bell Labs layered space-time (V-BLAST), the symbol-by-symbol power allocation method used in synchronous systems is invalid. According to this issue, a block-by-block power allocation algorithm is proposed to minimize the Block Average Bit Error Rate (BABER). This algorithm firstly computes the instantaneous SNR per symbol. Then BABER of asynchronous block is worked out. Finally, the optimum transmit power of each antennas is obtained from the solution of an optimization problem. Simulation results in flat Rayleigh fading channel show that the proposed algorithm has 2 dB gain at BER of 10-3 compared to the 2Tx2Rx asynchronous V-BLAST using BPSK modulation and zero-forcing detection.
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Received: 10 April 2009
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Corresponding Authors:
Tang You-xi
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2010, Vol. 32 
