A review on modulation techniques in multiband-orthogonal frequency division multiplexing in ultra-wideband channel

摘要

This paper describes a review on mapping or modulation techniques used in multiband orthogonal frequency division multiplexing (MB-OFDM) in ultra-wideband (UWB) channel. QAM, BPSK and QPSK modulation techniques are commonly used in this system due to their smooth power spectrum, low bit error rate (BER) and low receiver complexity. The new constant envelop modulation technique is proposed since it has the capability to improve the power spectrum density and BER performance. Continuous phase modulation (CPM) scheme could be used to reduce the complexity at the receiver. The constant envelop characteristics of CPM has to be analyzed in order to adapt this scheme in (MB-OFDM) UWB system.