Joint Channel Estimation and Side Information Scheme for Adaptively Selected OFDM Signals

Orthogonal frequency division multiplexing (OFDM) is a special form of multi-carrier modulation which is robust against the multipath effect and inter symbol interference (ISI). However, it is very sensitive to nonlinear effects due to the high peak-to- average power ratio (PAPR) owned by the transmitted signals. To reduce PAPR and improve the error performances of the OFDM signals over fading channels, an OFDM system in which adaptive symbol selection scheme (ASSS) and channel estimation are combined together can be used. The data rate is reduced somewhat in the conventional transmission method because the side information is transmitted with the data information. In order to increase data rate, we propose a new technique to transmit the side information separately in the pilot tones. We demonstrate that the proposed technique can give reasonable bit error rate (BER) performance over fading channels while effectively reducing the PAPR.