Error vector-based measurement procedures for RF digital transmitters troubleshooting

The rapid growth of modern telecommunications systems has created the need of getting new test equipment as well as measurement techniques up and running in a very short time. With particular regard to transmitters troubleshooting, new measurement methods and procedures are clearly claimed for, because those based on the analysis of constellation diagrams, currently supported by major manufacturers, show some intrinsic limitations. Some original and straightforward measurement procedure, based on the use of error vector (EV), which overcome the aforementioned limitations, are proposed in the paper. They are addressed to the I/Q section of transmitters, and are particularly affective both in terms of accuracy and measurement time when only one or two I/Q impairments are significant. Besides providing an analytical description, the paper gives details of the extended experimental campaign carried out on actual telecommunication signals in order to assess the performance of the proposed procedures.