Is the cyclic prefix necessary?

TL;DR

This paper demonstrates that cyclic prefixes can be eliminated in SC-FDE and OFDM systems by increasing receiver complexity, maintaining SINR performance asymptotically, and reducing channel use overhead.

Contribution

It introduces a method to remove the cyclic prefix in SC-FDE and OFDM, with a moderate increase in receiver complexity, without sacrificing asymptotic SINR performance.

Findings

SINR remains asymptotically unchanged without CP

Eliminating CP reduces channel use overhead

Receiver complexity increases moderately

Abstract

We show that one can do away with the cyclic prefix (CP) for SC-FDE and OFDM at the cost of a moderate increase in the complexity of a DFT-based receiver. Such an approach effectively deals with the decrease in the number of channel uses due to the introduction of the CP. It is shown that the SINR for SC-FDE remains the same asymptotically with the proposed receiver without CP as that of the conventional receiver with CP. The results are shown for $N_t$ transmit antennas and $N_r$ receive antennas where $N_r \geq N_t$.