TABLE OF CONTENTS Peak code domain error (PCDE) [45] is used as a specification, similar to EVM, for WCDMA systems. The advantage of a peak code domain error requirement, over relying solely on EVM, is to ensure that modulation errors are spread evenly over the codes. This prevents errors from disproportionately impacting a few codes, for which performance would be degraded. This phenomenon cannot be detected using an error vector magnitude test, as this is measured before despreading. PCDE is specified in the WCDMA specifications published by the Third Generation Partnership Project (3GPP).
If the error is evenly distributed across the codes, the PCDE is given by:
where EVM is the error vector magnitude and S is the spreading factor. For example, if EVM is 12.5%, with a spreading factor of 256, the resulting peak code domain error is ?42.14dB. Since the error is assumed to be evenly distributed, this is effectively the mean code domain error and not strictly PCDE.
Rho ( ?) is the ratio of correlated power to total transmitted power for a CDMA signal (i.e., the degree of correlation between a perfect reference signal and the actual signal generated by the transmitter). It is specified in the IS-95 and CDMA2000 standards. This correlated power is derived following the removal of frequency, phase, and time offsets and subsequently performing a cross-correlation between the corrected, measured signal and the ideal reference. Any of the transmitted energy that does not correlate...
