Training sequence design for data-aided timing acquisition in UWB radios

The overall system efficiency of impulse radio communications relies critically on judicious allocation of transmission resources, a portion of which should be used to ensure successful timing acquisition. Data-aided timing offset estimation has been derived by the authors based on the maximum likelihood (ML) criterion, where only symbol-rate samples are needed for low-complexity receiver processing. To minimize the mean-square timing errors of these ML synchronizers while at the same time maximizing the average system capacity, the training sequence design and the transmit power allocation are investigated in this paper. The optimum training pattern, as well as the number, placement, and power allocation of training vs. information-bearing symbols, are formulated as a resource allocation optimization problem, whose solution offers the optimum system-level performance with the minimum amount of resources consumed.