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Abstract

A signal acquisition system rapidly acquires carrier phase and symbol timing of a received PSK-modulated communication signal having a 110-symbol pattern through joint estimation of carrier-phase adjustment and symbol-timing adjustment by processing a common set of sampled data. A reference signal at a local oscillator frequency is mixed with a received communication signal to provide the communication signal at an intermediate frequency. The intermediate-frequency communication signal is converted into a digital communication signal, which is formatted into in-phase (I) and quadrature-phase (Q) components. A sampling circuit samples the I components at twice a predetermined symbol rate to provide a first series of I-component samples at the predetermined symbol rate and a second series of I-component samples that are intermediate to the first series of I-component samples and at the predetermined symbol rate, and for sampling the Q components at twice the predetermined symbol rate to provide a first series of Q-component samples at the predetermined symbol rate and a second series of Q-component samples that are intermediate to the first series of Q-component samples and at the predetermined symbol rate. A processor processes the samples to estimate a phase-adjustment value and a symbol-timing-adjustment value. The phase of the reference signal is adjusted in accordance with the phase-adjustment value and the timing of the sampling is adjusted in accordance with the symbol-timing-adjustment value.

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