TR Pre-Filter Design for Channel Shortening in MISO-OFDM Systems

This letter investigates the design of the pre-filters for MISO-OFDM systems to shorten the cyclic prefix (CP). The pre-filters are optimized to minimize the length of the impulse response of the equivalent channel while promoting its output signal power. Simulation results demonstrate that when the number of transmit antennas is 2 or more, the length of CP can be shortened to 0 and the bit error rate is very close to that of the MRT scheme with full-length CP and is lower obviously than that of the basic time reversal (TR) filtering scheme with full-length CP.