Analytical models for channel aging and synchronization errors for base station cooperation

Base station cooperation is a powerful technique for eliminating inter-cell interference and enhancing spectral efficiency in cellular networks. However, impairment effects due to channel time variance, channel estimation, feedback quantization and imperfect synchronization among base stations are limiting the potential gains. In this paper, we present a comprehensive signal model for multi-user multi-cellular systems with cooperating base stations, which includes those essential impairments. The effect of each impairment is captured by its mean square error (MSE), for which exact analytical expressions and accurate approximations are derived and numerically verified. Those MSE expressions can be used for link-layer abstraction, system-level evaluation and signal to interference ratio (SIR) analysis. We evaluate the spectral efficiency of cooperative networks considering a real-world scenario and find that channel aging has the largest impact on performance degradation.