Performance evaluation of an OFDM system employing Viterbi decoded QPR in AWGN channel conditions

Orthogonal frequency-division multiplexing (OFDM) has been shown to be a spectrally efficient modulation technique with inherent frequency diversity potential. Furthermore, by employing quadrature partial response (QPR) in an OFDM system, an even higher spectral efficiency can be obtained than with quadrature phase shift keying (QPSK) subcarrier modulation. Unfortunately, this is obtained at the cost of BER performance loss when compared to QPSK. However, this loss can be regained by using Viterbi decoding in the receiver. The paper presents a performance evaluation of an OFDM system employing Viterbi decoded QPR under additive white Gaussian noise (AWGN) channel conditions as an alternative to QPSK modulated OFDM.