Carrier and Timing Synchronization of BPSK via LDPC Code Feedback

In traditional receiver architectures, symbol acquisition and tracking are performed using phase lock techniques that are independent of the channel-code decoding process. In [1] feedback from the constraint-node side of a bi-partite graph is used to estimate symbol frequency and timing offset in a baseband pilotless transmission. In [2] soft information feedback from an LDPC decoder is used to recover carrier phase information under the assumption of perfect symbol timing. In this paper we address the problem of joint carrier-phase and symbol timing recovery. The proposed system is able to perform within 0.3 [dB] of the code performance with perfect knowledge of carrier phase and symbol timing.