Cyclic Prefix Overhead Reduction for Low-Latency Wireless Communications in OFDM

Mobile wireless communications are constantly struggling to reduce air interface latencies in order to make the overall systems more responsive to human interaction. Latency reductions in OFDM require substantial reductions in the OFDM symbol lengths, which are limited by the cyclic prefix length according to the maximum channel delay spread to be supported. This paper explores a new scheme that achieves significant overhead reduction by leaving only the cyclic prefix corresponding to the first OFDM symbol and removing the remaining ones in a time transmission interval, while modifying the general transmission procedure. An algorithm is proposed at the receiver for cancellation of any inter-symbol and inter-carrier interference appearing in multipath channels, which benefits from significantly low computational complexity. Link-level simulations show excellent results in terms of block error rate and achievable throughput when applied to an LTE system, therefore allowing for significant symbol length reductions and reduced air interface latencies.