An Improvement to the Multicarrier Complementary Phase-Coded Radar Signal Using Signal Distortion Technique

This paper aims to reduce the Peak-to-Mean Envelope Power Ratio (PMEPR) of a Multicarrier Complementary Phase-Coded (MCPC) signal. A MCPC signal consists of N subcarriers which are phase modulated by N distinct phase sequences. Each of these N subcarriers is spaced 1/tb apart from each other, where tb is the duration of each phase element, constituting an orthogonal frequency division multiplexing (OFDM) signal. A signal distortion technique, companding, is used to reduce the PMEPR of the generated MCPC signal. Further, the use of level shifting technique on the MCPC signal and consequent application of the companding technique reduces the abrupt variations in the MCPC signal. A comparison of the complex envelopes, autocorrelation, and ambiguity functions of the MCPC signal obtained by the above-mentioned methods is performed which exemplifies the advantage of application of level shifting and companding over the conventional method.