Sum-rate increase with the hybrid of interference cancellation and busy burst interference avoidance

The busy burst (BB) concept for time division duplex (TDD) systems mitigates excessive interference by means of receiver feedback; potential transmitters that sense a BB above a certain threshold must refrain from transmitting. As strong received BB power, due to TDD channel reciprocity, implies that the interference caused to an ongoing transmission is equally strong, a protection radius around active receivers is established. In order to boost the sum-rate in shared spectrum networks, a novel combination of the BB protocol with interference cancellation at the receiver is presented in this paper. Assuming that a receiver is able to cancel the strongest interfering signal, one interfering transmitter can be allowed within the exclusion range of an active receiver. Numerical results indicate that the combination of BB interference avoidance with strongest interference cancellation increases the sum-rate by up to 45%. The resulting probability density function (pdf) of the residual interference for this hybrid approach is derived by adjusting the shifted log-normal approximation that models BB interference.