Digital predistortion system and method of frequency selectivity harmonic suppression

Abstract

The invention relates to a digital predistortion system and method of frequency selectivity harmonic suppression. The digital predistortion system and method of frequency selectivity harmonic suppression are characterized in that a parallel binary channel predistortion unit processing framework is utilized; a main predistortion device is used to suppress in-band distortion of a power amplifier at the center frequency; an auxiliary predistortion device is used to suppress harmonic distortion of the power amplifier at the selected frequency; a predistortion parameter estimation module is used to acquire a predistortion coefficient matrix according to the output signals of the main predistortion device and the auxiliary predistortion device and sampling output of the power amplifier at the center frequency and the selected frequency; and the main predistortion device and the auxiliary predistortion device perform predistortion coefficient adjustment according to the predistortion coefficient matrix. The digital predistortion system and method of frequency selectivity harmonic suppression can only suppress the harmonic interference at the interesting target frequency point, thus being lower in the implementation complexity, compared with a multi-channel predistortion method which suppresses a plurality of harmonic waves at the same time. Besides, the digital predistortion system and method of frequency selectivity harmonic suppression perform weighing synthesis on the optimization target of the main predistortion device and the auxiliary predistortion device to form a single target function, and introduce a particle swarm algorithm, thus accelerating the convergence speed of the algorithm.

Description

technical field [0001] The invention relates to the field of communication technology, in particular to a digital predistortion system and method for frequency-selective suppression of harmonics. Background technique [0002] The power amplifier (Power Amplifier, PA) is the core device of the RF front-end of a modern wireless communication transmitter, and it is also the main source of its energy consumption. At the same time, the inherent nonlinearity of the power amplifier is also the main factor affecting the quality of the transmitted signal. It will not only cause unfilterable distortion of the in-band signal and affect the quality of its own information transmission; it will also generate spectrum regeneration and spurious emissions, potentially affecting Interference is generated by other communication systems operating in the adjacent range of the corresponding spectrum. Moreover, since the high-order spectrum modulation signals widely used in modern wireless commun...

AI Technical Summary

Problems solved by technology

The traditional single-band digital predistortion technology mainly suppresses the in-band distortion and spectrum regeneration of the power amplifier, while the nonlinearity of multi-band parallel power amplifiers can also cause spurious emissions, mainly including third-order intermodulation distortion and harmonic distortion, especially Harmonic interference is caused when the harmonic components of the low-band signal fall into the high-band

The traditional method uses RF filters to filter out spurious emissions. However, this method is difficult in multi-band transmitting systems. The center frequency cannot be dynamically set, and insertion loss will be introduced, which will reduce the transmit power.

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