Equalisation technique for high mobility OFDM-based device-to-device communications using subblock tracking

This study presents a `subblock tracking´ based equalisation technique for orthogonal frequency division multiplexing (OFDM) based device-to-device communications over high mobility environment. This technique is to use a rectangular-shaped receive window to partition the OFDM block into subblocks rendering the channel response of each subblock to be time-invariant, thereby allowing one to equalise the channel frequency response on each subcarrier of the subblocks simply by a single tap. The equalised signals are then combined to give the final output, where the combination weights are designed to minimise detection errors. The authors mathematically characterise the detection performance by deriving the signal-to-interference ratio as a function of channel-time-variation and the numbers of subblocks. To further enhance the proposed design without imposing computational consumption, a subblock tracking scheme with partially overlapped partition is presented and theoretically analysed. Simulation results demonstrate the advantages this method over the conventional schemes in high mobility environment.