Analysis of SCCL as a PN-code tracking loop

We introduce the application of SCCL that is based on sample-correlate-choose-largest procedure as a coherent baseband PN-code tracking loop applying biphase-level signals. Three adjacent estimates are formed by correlating the samples of the baseband waveform for each bit. We choose the corresponding timing (phase) of the estimate with the largest magnitude as the current correct timing (phase) and update it for each bit. Only one summation circuit is required due to the digital realization of the SCCL. The correlation properties of the samples from maximum length codes using the biphase-level signal set are investigated. Tracking performance is theoretically analyzed in both steady-state and transient conditions via a finite-state Markov chain model. The numerical results demonstrate strong PN-code tracking characteristics of SCCL