Phase reconstruction receiver with compensation of nonlinearities

A number of modern wireless systems use modulation schemes like CPFSK, GMSK and DPSK, where the information to be transmitted is exclusively coded in the phase change of the RF-signal. Thus a phase reconstruction receiver can be used, which is based on a simple limiter for digitization. With respect to implementation costs and power consumption this is a very attractive receiver concept. However, due to non-idealities of the RF-front end, the receiver signal can deviate from the ideal PSK-constellation. This can result in performance losses compared to a linear receiver with a high resolution A/D-converter. For the more sophisticated modulation schemes like MPSK, which will be extensively used for high-data rate systems, these performance losses can be severe. Thus, in this contribution, a digital compensation technique for a phase reconstruction receiver is proposed, which reduces the nonlinear distortion introduced by the limiter. Using this method an excellent performance can be obtained with a phase reconstruction receiver also for the more sophisticated modulation schemes.