An adaptive predistorter using modified neural networks combined with a fuzzy controller for nonlinear power amplifiers
✍ Scribed by Hong-min Deng; Song-bai He; Jue-bang Yu
- Publisher
- John Wiley and Sons
- Year
- 2003
- Tongue
- English
- Weight
- 272 KB
- Volume
- 14
- Category
- Article
- ISSN
- 1096-4290
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✦ Synopsis
In digital radio systems, high data transmission rates require the use of spectrally efficient linear modulation techniques; however, these techniques are generally sensitive to nonlinearity caused by the high-power amplifier (HPA) employed in transmitter systems. The nonlinearity of HPA is potentially responsible for spectral spreading, adjacent channel interference (ACI), and degradation of bit-error rates (BERs). This article proposes an adaptive predistortion scheme to compensate for the HPA's nonlinearity by combining adaptive structure-varying neural networks and a fuzzy controller. Simulations show that this predistortion scheme can very effectively prevent the warping of the signal constellations, thus reducing the system's BER and learning time.