This paper provides a simulation method that provides two Rayleigh fading signal envelopes of a desired correlation coefficient. This is based on recent work and uses an improved technique (iterative step) to achieve higher numerical accuracy between the desired and the resultant cross correlation coefficient. The average fade duration is used as a measure of the diversity scheme performance, and various diversity combining techniques (switch combining: Pure Selection and Threshold Selection - switch and stay, switch and examine) are examined. It is shown that non-zero cross correlation affects the performance of the particular combining technique differently. A model to predict the diversity performance, for a given correlation coefficient and signal level, is examined.