PARALLEL DIGITAL QAM-MODEM BASED ON BANKS OF HOMOGENEOUS DIGITAL COMPLEX BAND-PASS FILTERS
The article is devoted to the development and implementation of quadrature amplitude modulation and demodulation algorithms based on banks of homogeneous digital complex bandpass FIR filters. The use of banks of homogeneous complex FIR filters makes it possible to obtain carrier orthogonal signals similar in shape to symmetrical signals with practical non-overlapping spectra. The procedure for obtaining the pulse response expression of a uniform digital complex bandpass FIR filter is considered. The frequency response and impulse response of such a filter are determined using schematic modeling. The bank of homogeneous complex FIR filters contains digital filters with the same structural scheme. The center frequency is selected by setting two coefficients. The results of modeling the quadrature amplitude modulation (KAM-16) data transmission system in Microcap environment are presented