Data aided phase tracking and symbol detection for CPM in frequency-flat fading channel

In this paper, a novel receiver for joint data detection and channel tracking on continuous phase modulation (CPM) operating under a frequency-flat time-varying Rayleigh fading channel is proposed. Due to the inherent memory of CPM, channel tracking on CPM is not as straightforward as on PSK and FSK, and therefore we first derive a phase estimation based CPM scheme to facilitate the phase tracking procedure. The most common method of channel tracking involves Kalman filter, which needs to know the channel model and environmental conditions. In here, we propose to use an alpha beta filter to realize a kind of ´blind´ tracking independent of channel conditions. The results show that, in environments where a detailed channel model is unknown and channel variation is considerable, the proposed receiver can provide satisfactory BER performance.