Coverage in Multi-antenna Tiered Macro/Femto Networks

The paper quantizes the joint effects of finite rate and delay of feedback channel on the performance of downlink transmissions and the coverage in co-channel multi-antenna tiered macro/femto networks. The per-tier probability of successful reception that signal to interference ratio (SIR) is larger than minimum SIR target is derived. Based on the quality of service (QoS) constraints, the radius of macrocell maximum coverage and no-coverage femtocell radius are obtained respectively. Simulation results indicate the probability of successful reception and the coverage of macrocell are both reduced by imperfect feedback. While if the defined quantization error increases and approximates to 1, the performance of downlink transmissions is improved and the coverage of macrocell is extended with the increasing of feedback delay.