Abstract
Novel direct-optimization approaches for designing prototype filters are developed. Tradeoff between inter-symbol interference (ISI) and stop-band power (SBP) can be made by adjusting weight parameters. Alternatively, a cap on SBP or ISI can be pre-specified in the designing process. A numerically efficient iterative procedure is developed to avoid matrix inversion in each iteration step. In addition, sensitivity with respect to timing error can be taken into consideration in the filter designs.