Multipath Mitigation Method for BOC Signals Dual Estimation Technology Based on Synthesized Correlation Function

Dual Estimation Technique (DET) is mainly used to achieve unambiguous tracking of high-order BOC signals. DET has a good tracking performance, but its anti-multipath performance need to be further improved. In this paper, the method of designing a synthesized correlation function(SCF) based on step-shape code symbol (SCS) is applied to the DET. Anti-multipath performance of DET is improved by introducing the special SCS signal to participate in the coherent integration process with the received signal. The improved DET is flexible in designing, no need of additional correlator, and only design a SCS vector to achieve anti-multipath performance improvement. The theoretical derivation and concrete implement of the improved DET are analyzed, and simulations are conducted in both anti-multipath and tracking performance. The results show that when the 4 order SCS vector is used, compared with the traditional DET, the multipath error envelope area of BOC (2,1) and BOC (14,2) signal tracked by the improved DET can be reduced 62.6 and 70.4% respectively. But at the same time, it will bring about 6 dB coherent integration gain loss. All of the above shows that this method is only suitable for the unambiguous and anti-multipath tracking of the strong BOC signals.