The impact of filters on the error vector magnitude in software defined radios

For an ideal communication system, matched filters which are compatible with transceiver structures that are used. Matched filters can maximize the signal to noise ratio (SNR) at the receiver for transmitted symbols. The performance of the ideal systems do not differ according to the filter structures, they can only change the band efficiency on account of bandwidth. In this study, by using software defined radio kits in the laboratory, measurements of error vector magnitudes (EVM) for various filter structures have been made. In our tests, by changing the roll-off factor of the root raised cosine filters (RRC), the error vector magnitude values have been obtained with respect to various receiver gain configurations. As a result of our tests, it has been shown that the changes made on filters do not only affect the bandwidth efficiency as opposed to the case in ideal systems, but also affect the error vector magnitudes.