Iterative Algorithm for Reducing the Peak-to-Average Power Ratio of Feedback-Controlled Multitone-Hopping CDMA Signals

SUMMARY A novel peak-to-average power ratio (PAR) control algorithm for feedback-controlled multitone-hopping code-division multiple access (FC/MH-CDMA) signals is proposed. In FC/MH-CDMA, since each chip consists of plural tones, the energy consumption due to a large PAR is not negligible at the transmitter. The proposed PAR control algorithm iteratively constructs a time-frequency code that achieves a preset, target PAR under the condition that all signals are asynchronously transmitted. A PAR of 1 dB is shown to be achievable, and the bit-error rate performance is shown to be only slightly influenced if the target PAR is set to be larger than 3 dB. The influence of quantization is also discussed in terms of its application to limited feedback channels.