The Low Complexity Algorithm Research On Muliti-h CPM Signal

Continuous Phase Modulation(CPM) technology is advantageous for itsefficient use of power as well as bandwidth. It has broad application prospects in thehigh-speed data transmission systems such as communication and aeronauticaltelemetry systerms. The multi-h CPM waveform has been selected by NASA andARTM to replace the outdated PCM/FM systerm. However, it’s limited inengineering applications since the high implementation complexity it sufferd aswell as the single-h CPM low-complexity algorithms do not fit for the multi-h forms.In this paper, several complexity reducing techniques are surveyed while animproved algorithm is proposed.Firstly, the CPM modulation and demodulation algorith ms are surveyed whiletheir corresponding performance are analysed. Then PAM decomposition algorithmand SSP-RSSD algorithm are chosen according to the algorithm performance underthe conditions of multi-index. We start with the analys is of signa l parameters on thebandwidth from the power spectral density of the signal bandwidth and combinewith signal simulation experiments to obtain the best parameters of the CPM signal.Then a research on Maximum likelihood sequence detection(MLSD) is made.Secondly, aimed at reducing the CPM algorithm complexity we use the PAMdecomposition algorithm to cut back the number of matched filters while theSSP-RSSD algorithm are chosen to decrease the trellis states. In the application ofoptimal detection algorithm based on the PAM decomposition and sub-optimaldetection algorithm derived the formula of the bit error rate and analyze itsperformance.According to the results of the analysis, under the same conditions, thevice-superior detection algorithm relative MLSD algorithm can significantly reducethe receiver complexity and performance loss is tiny. In the tilted phaserepresentation on the basis of the SSP-RSSD algorithm performance analysis andsimulation results show that the algorithm can reduce the number of phase states.Finally, the PAM decomposition algorithm is applied to the multi-h CPMsignals. Then the improved algorithm for the bit error rate formula is derived and the Monte-Carlo simulation is conducted. The results show that it only cause a smallperformance penalty based on the PAM decomposition algorithm in multi-indexrelative MLSD algorithm can also significantly reduce the number of matched filterwith a a sharp decrease of the computational complexity. Then a method of a unionalgorithm is proposed. The PAM decomposition algorithm which based on themulti-h signal is applied to the front processing while the SSP-RSSD algorithm isextended up to multi-h form to further reduce the complexity of the algorithm in theend processing. Theoretical analysis and simulation results show that the algorithmcan reduce the number of matched filter and the number of states, reducing themaximum complexity.In summary, this paper reduce the complexity of the multi-h CPMdemodulation method of analysis, and effective improved algorithm, which greatlysimplifies the complexity of the receiver.