CARRIER ACQUISITION AND TRACKING

Abstract

This chapter focuses on the application of phaselock techniques to acquire and track the carrier frequency of a modulated waveform. It focuses on the acquisition and tracking of data‐modulated waveforms involving the baseband or Costas implementation of the phaselock loop (PLL). Acquisition and tracking of the carrier phase and frequency of waveform‐modulated carrier signals is essential for optimum coherent detection and examples are given for multiphase shift keying (MPSK), quadrature phase shift keying (QPSK), offset QPSK (OQPSK), and minimum shift keying (MSK) modulations. Preceding the PLL with a bandpass limiter serves as a gain control function that mitigates the impact of signal level fluctuation on the PLL dynamics. The chapter examines the transient characteristics of the phase response to several input functions using the phase‐error transfer function. The squaring loss is evaluated for BPSK and QPSK modulation. The PLL tracking performance is evaluated based on Monte Carlo simulations for BPSK‐ and QPSK‐modulated waveforms.