Effect of the Asymmetry between Downlink and Uplink on TDD-MIMO Systems
Dai Kang①; Song Rong-fang①②③
①College of Communication & Information Engineering, Nanjing University of Posts & Telecommunications, Nanjing 210003, China; ②National Mobile Communications Research Laboratory, Southeast University, Nanjing 210096, China; ③ZTE Corporation, Nanjing 210012, China
Abstract：Time-Division Duplex (TDD) and Multiple-Input Multiple-Output (MIMO) are the key techniques in the beyond third generation (B3G) mobile communication systems. In the conventional literatures on TDD, the channel state information at transmitter is obtained by assuming the reciprocity between uplink and downlink. However, affected by the unbalance of the Radio-Frequency (RF) circuitries in practice, the reciprocity between uplink and downlink can not be maintained, which will cause a decrease of the performance. In this paper, the asymmetry effect is analyzed in detail and the RF feedback strategy is proposed to eliminate it. Simulation results show that the RF feedback strategy performs much better than the conventional uplink reuse and the capacity of the MIMO systems is greatly improved.
代康; 宋荣方. 上下行信道不对称性对TDD-MIMO系统的影响[J]. 电子与信息学报, 2007, 29(8): 1903-1905 .
Dai Kang; Song Rong-fang. Effect of the Asymmetry between Downlink and Uplink on TDD-MIMO Systems. , 2007, 29(8): 1903-1905 .
2007, Vol. 29 
