Compact Pulse Shaping for Efficient PAM/QAM Signaling

Compact pulse shaping (CPS) is considered with PAM/QAM signals to improve the performance/bandwidth tradeoff. CPS signals are constructed by targeting a finite impulse response of a pulse shaping filter as opposed to the traditional method of targeting a finite frequency response. CPS QAM signals can be optimally decoded using Viterbi decoding on I and Q channels independently. In the case of non-rectangular constellations, a simple adjustment is presented to correct any invalid QAM symbols that result from independent I and Q decoding. Minimum distance calculations indicate that CPS QAM provides between 2.04 and 5.4 dB of gain, depending on constellation size, over raised cosine filtering, when compared at a given value of the normalized bit bandwidth B₉₉T_b.