Code-aided Synchronization for DVB-RCS2

The second generation digital television broadcasting interactive satellite system (DVB-RCS2) plays a very important role in the satellite communication return channel. In actual application, interference from timing deviation and carrier frequency deviation will be encountered, especially turbo codes are very sensitive to carrier frequency deviation, so the design of efficient receiver for DVB-RCS2 must consider the synchronization problem. In this paper, we integrate the synchronization scheme into the decoding process of turbo codes. We use the log-likelihood ratio provided by the decoder for iterative synchronization, and use the result of cyclic redundancy check (CRC) as a stop signal for iterative detection, we call this approach code-aided (CA) synchronization. Simulation experiments show that the CA synchronization scheme is significantly better than the traditional data-assisted synchronization scheme, even comparable to the performance in ideal synchronous scenarios. In addition, combined with the CRC check, redundant iterations are avoided.