Research And Realization Of Reduced-complexity Detection And Carrier Phase Recovery For Multi-h CPM

Multi-h Continuous Phase Modulation(Multi-h CPM) which not only has the characteristics of constant envelope and continuous phase, but also has high bandwidth efficiency and good BER performance, has wide application prospects. But it is often plagued by issues of high detection complexity and synchronization, so it has developed slowly. This paper mainly studies low complexity detection algorithm and carrier phase synchronization algorithm for Multi-h CPM.Firstly, according to the maximum likelihood sequence detection for Multi-h CPM, there are too many matched filters and trellis states, and it is hard to realized. So it is necessary to reduce detection complexity. And the algorithms of reducing matched filters and reducing trellis states are proposed respectively in this paper. The simulation results indicate that, by choosing proper simplified parameters, a significant detection complexity reduction can be achieved by the proposed algorithms at the cost of moderate loss in performance.Secondly, carrier phase synchronization is very important in coherent sequence detection, but there are few carrier phase synchronization algorithms for Multi-h CPM. Based on the existing carrier phase synchronization algorithm for single-h CPM, a decision-directed carrier phase synchronization algorithm based on Laurent decomposition for Multi-h CPM is proposed in this paper. The simulation results indicate that, in the environment of large doppler frequency, the estimation performance of the algorithm is good and it can approach the MCRB.Finally, based on the analysis of the theory discussed above, a Multi-h CPM IF signal experiment system, including modulator and demodulator, is designed. And the demodulation is achieved in the ideal channel, which has proved the feasibility of the proposed algorithms.