Feng Xingle,Zhu Shihua,Wu Linjun
(School of Electronics and Information Engineering,Xi'an Jiaotong University,Xi'an ¡¡710049,China)
Abstract:In order to increase spectral efficiency,a novel hybrid detection algorithm in vertical-Bell labs layered space-time (V-BLAST) system employing adaptive modulation was proposed. In view of the characters of adaptive modulation, the reverse ordering was employed at lower signal to noise ratio (SNR) to change the invalid subchannel to a valid one after iterative interference cancellation, and the forward ordering was used to turn the unsaturated subchannel into a saturated one at higher SNR.The hybrid ordering achieves higher spectral efficiency than the existing forward and reverse orderings with little increase of complexity. Simulation results show that in the V-BLAST system with 4 transmitting and 4 receiving antennas for a target bit error rate of 10-3, the hybrid ordering performs 8£¥ better (at SNR of 10dB) than the forward one and 6£¥ better (at SNR of 30 dB) than the reverse one.
Keywords:Bell labs layered space-time system; adaptive modulation;detection algorithm