OFDM/MDPSK system performance improvement in the presence of frequency offset

To improve OFDM system performance in the presence of frequency offset, in this paper we propose a OFDM/MDPSK receiver with reconfigurable differential detection (RDD) algorithm that can be used for the MDPSK signal reception. Important feature is that the proposed algorithm does not require pilot symbols, and therefore there is no bandwidth efficiency loss. The analysis shows that the bit error probability of the proposed algorithm is nearly constant in a wide frequency offset range and equal to the error probability for zero frequency offset. Bit error rate (BER) as a function of the energy per bit to noise power spectral density ratio (E_b / N₀) in the AWGN channel, for different values of modulation level M is very close to performance of the OFDM system with differential detection at the receiver.