Short-wave digital pre-distortion method based on non-uniform quantization lookup table

Abstract

The invention discloses a short-wave digital pre-distortion method based on a non-uniform quantization lookup table, and the method comprises the steps: selecting a pre-distortion structure, collecting a current pre-distortion signal and a feedback signal, and carrying out the synchronous alignment of the currently collected signals; calculating a normalized mean square error of the current inputsignal and the pre-distortion output signal; judging whether the currently calculated normalized mean square error is greater than a preset target value or not, if so, calculating a pre-distortion coefficient by adopting a least square method, updating the lookup table according to the pre-distortion coefficient, and performing pre-distortion on the next round of pre-distortion by adopting the updated lookup table; otherwise, adopting the current lookup table to perform pre-distortion in the next round. According to the method, the memory polynomial model of the non-uniform quantization tableindex is adopted, so that the table index precision is improved, and the performance of a digital pre-distortion system is further improved.

Description

technical field [0001] The invention belongs to the technical field of self-adaptive digital pre-distortion, and in particular relates to a short-wave digital pre-distortion method based on a non-uniform quantization look-up table, which is suitable for improving the efficiency of a short-wave radio frequency power amplifier and the index of a digital pre-distortion system. Background technique [0002] The wireless electromagnetic wave frequency with a frequency range between 1.6MHz and 30MHz is usually called the shortwave frequency band, and the use of shortwave frequencies for worldwide broadcast transmission for one-way communication is usually called shortwave broadcasting; radios that can receive one of the above-mentioned frequencies are called For short wave radio. Since short-wave communication mainly relies on the back and forth reflection and refraction between the ionosphere and the ground for propagation, short-wave communication can travel far regardless of da...

AI Technical Summary

Problems solved by technology

For the convenience of implementation, the shortwave digital predistortion structure uses a lookup table (Lookup Table, LUT). The address indexes of the existing lookup tables all use the mean value index, that is, the table indexes at equal intervals are used for the amplitude of the input signal, and the power amplifier's The gain pre-adjustment value is stored in the lookup table as the index corresponding content, but when the input signal changes with the external environment and time, this uniformly quantized lookup table cannot reflect this change, resulting in a decline in predistortion performance

Images