APPARATUS, SYSTEM AND METHOD FOR PERFORMING PEAK POWER REDUCTION OF A COMMUNICATION SIGNAL

摘要

A method, system and apparatus are provided for effecting peak power reduction of a communication signal. In particular, the method achieves peak power reduction by generating an out of band peak power reduction (OBPPR) signal; which reduces the peaks of the waveform. The OBPPR signal can be generated at baseband, IF or RF. The method can be implemented in the digital domain using FPGA, DSP or ASIC or can be implemented in the analog domain using discrete circuitry, RFIC's or MMIC's or multi-chip modules. The method does not introduce significant amounts of EVM or sacrifice any capacity and as such offers considerable advantages compared to current state of the art methods. Furthermore, the method can be combined and is approximately additive with existing power reduction methods to effect greater levels of peak power reduction. The inventor has demonstrated a system which takes an OFDM waveform with a PAPR of 7.16 dB as an input, and produces an output waveform with a PAPR of 4.5 dB, while introducing very negligible amounts of EVM. The inventor has also demonstrated a two carrier OFDM transmitter as well as a Multi-Carrier GSM transmitter with 8 carriers, where the OBPPR signal was able to reduce the peak to average power ratio of the waveform from 9 dB to 2.8 dB and from 9.5 dB to 4.2 dB respectively.

主权项

1. A method of reducing the peak to average power ratio of a communication signal which comprises of:
a. Clipping or compressing the communication signal to reduce the peaks of the waveform to arrive at a clipped communication signal; b. Subtracting the original communication signal from the said first clipped communication signal to arrive at an unfiltered distortion signal; c. Filtering the said unfiltered distortion signal to eliminate or reduce distortion at frequencies where it is undesirable to have distortion products, to arrive at a filtered distortion signal; d. Recombining the said filtered distortion signal with the said communication signal with the appropriate phase, to arrive at a composite signal with a reduced peak to average power ratio where a portion of the peak power reduction has been achieved by components of the said composite signal which fall at frequencies outside of the said communication channel.