Multi-frequency encoding technique using phase coupling in wireless communication systems

In this paper, a novel encoding concept using frequency diversity strategy and bispectrum-based signal processing is suggested for wireless communication systems. According to proposed approach, binary data (0s and 1s) is transmitted through a pair of mutually orthogonal triplet-signals containing phase coupled frequency tones. Phase coupling in each triplet-signal is given by group of three tones such that phase related to one frequency value is equal to the sum of phases related to other two frequencies. Novel third-order test statistics computed in the form of magnitude bispectrum peak values are suggested for detection and discrimination of received triplet-signals in noisy and fading communication radio channels. In order to discriminate triplet-signals at the receiver, the sensitivity of bispectrum to phase coupling is exploited. Bit error rate (BER) performance assessed for additive Gaussian channel noise and fast fading demonstrates considerable improving of noise and fading protection provided by suggested bispectrum-based technique comparing to the common multiple frequency shift keying (MFSK) scheme using common energy-based strategy for signal detection and discrimination.