Combined effect of the carrier recovery and symbol timing recovery error on the P/e/ performance of QPR and offset QPR systems

The combined effect of sampling offset and phase error on the probability of error performance of quadrature partial response (QPR) and offset QPR systems is investigated. Techniques for the derivation of the system probability of error performance are demonstrated for digital transmission systems, limiting the discussion to the in-phase channel only. The Gram-Charlier series expansion method is used to calculate the accurate probability of error expression. An evaluation of the effects of timing offset, phase error, and the Gaussian noise is provided, showing that the error performance of the offset QPR system is consistently worse than the QPR system. Good agreement is demonstrated between the results obtained by a computer simulation and the Chernoff bound.