Effect of interpolation filter in digital quadrature amplitude modulation signal resampling

In this study, a closed-form equation is derived which relates the mean-squared error (MSE) to the frequency response of the interpolation filter. Effects of additive white Gaussian noise and timing jitter on the MSE are accounted for in the equation. By using properties of the Nyquist signalling pulse, a simple approximation to the MSE equation is obtained, which is found to be accurate over the range of excess bandwidths commonly used in quadrature amplitude modulation receivers.