Timing synchronization reciprocity error cancellation in OFDM/TDD coordinated multi-point transmission system

The timing synchronization reciprocity error(TSRE) is modeled and investigated in this paper, which can be found in an OFDM/TDD coordinated multi-point transmission(CoMP) system. In order to avoid its adverse impact on the radio frequency(RF) calibration, we improve the traditional calibration algorithm. Moreover, we propose two robust precoding schemes to alleviate the performance degradation of the multi-user CoMP system caused by the TSRE. The design criteria of these precoding schemes are based on compensating the linear phase rotation at every subcarrier and maximizing the lower bound of the average signal-to-leakage-plus-noise ratio(SLNR). Simulation results demonstrate that the proposed robust precoding schemes can achieve higher system throughput than the conventional SLNR precoding scheme under the non-ideal reciprocity situation.