A new family of NDA carrier phase detectors for coherent M-PSK receivers

A new family of NDA (non data aided) carrier phase detectors for M-PSK coherent receivers operating in AWGN channels is defined. The behavior of the phase detectors is explored using stochastic theory, and it is found that the phase detectors´ gain curves are independent of AGC performance and signal-levels. Furthermore, these self-normalizing properties allow the performance requirements of the AGC circuit to be relaxed considerably. Analysis of the self-noise of the phase detectors is presented, and their closed-loop phase error variance is calculated as well as simulated and found to be comparable to that of DD (decision directed) detectors. The phase detectors are shown also to possess a simple hardware realization, which allows for their straightforward and efficient implementation within an FPGA or ASIC. Finally, an adaptive scheme is outlined, one which aims to produce a phase detector that (along with the previously attained AGC independence) is independent of the SNR and M.