A Novel Multi-Carrier System Based on Maximum-Likelihood Sequence Detection in Frequency Domain

Spectrum and power efficiency of an OFDM system may be severely degraded by its cyclic prefix. In the paper, a novel multicarrier system named MLSD-MCM is proposed in order to improve the efficiency. The novel system does not depend on the orthogonality among subcarriers, but on the convolutional constraint relationship among them. The detection algorithm is the frequency-domain maximum-likelihood sequence detection (MLSD) based on the Ungerboeck metric. The convolutional constraint length is approximately 2 and thus the complexity is rather limited, which is attributed to the application of the square-root-Hanning window. Both theoretical analysis and simulation results prove that the MLSD-MCM technology is effective and feasible in AWGN and ITU-VA channels.