Interference-mitigating broadband secondary user downlink system: A time-reversal solution

The spatial and time focusing effects of time-reversal technology make it an ideal candidate for the low interference downlink system to relieve the coexistence issues among different wireless communication systems. The transmitting power would be concentrated at the intended receiver and the leakage to unintended receivers would be automatically suppressed. In this paper, a time-reversal based secondary user downlink system with the coexistence of primary users is proposed. The primary user´s performance loss is investigated in terms of effective SINR degradation and achievable data rate deduction. It is illustrated through numerical examples that the time-reversal downlink system relieves the primary user´s performance loss as well as achieves satisfying power efficiency compared with the traditional direct transmission.