Throughput analysis and system parameter optimization of space sense based random access for TDD WLANs

A space sense based random access (SSRA) scheme is introduced for the uplink of time division duplex (TDD) WLANs with multiple receive antennas. In SSRA scheme, each user performs space sense process to predict the post-detection signal-to-interference-and-noise-ratio (SINR) of data packets. If the predicted SINR is larger than a given threshold, the user considers the channel idle and is permitted to transmit channel estimation sequence and data packet like hybrid ALOHA. Successful channel estimation means successful packet reception. An approximation of the throughput of this SSRA scheme is given. We also make efforts to find the optimized system parameters by numerical simulations.