An adaptive predistorter for TDMA transmitters using a heterodyne architecture

This report presents results on the development of an adaptive predistorter for a generic TDMA transmitter A heterodyne architecture was used with the quadrature modulator and demodulator implemented as digital circuits. Previously reported results have indicated that increasing the look-up table (LUT) size improves the ACPR. Our results showed an opposite trend. Typical adjacent channel power rejection (ACPR) values of -57 dB were achieved using a 16 point LUT. The small LUT size may be attributed to memory effects inherent in a heterodyne system.