a digital receiver with a polyphase structure extracts specific channel data from multi - channel discrete time data . an input signal is sequentially delayed by a plurality of delays connected in series . the input signal and each sequentially delayed signal are processed by two down - samplers , for lowering the sampling rate , and two filters , for filtering for a desired channel of the input signal . each down - sampler is connected in series with one filter . also included are two pluralities of adders , the number of adders of each plurality is equal , and each of the adders of each plurality is connected in series . the number of adders is equal to two times the number of delays . the adders recombine the outputs of the filters , each adder recombining two filter outputs . the order that the adders recombine the signal coincides with the order that the signal was delayed . by sequentially delaying the digital input signal , down sampling and filtering each sequentially delayed signal , and recombining the filtered signals , the time data can be processed at a lower rate than the digital input signal rate .