Study on the General Design Scheme of UNB Modulation Formats

Abstract

As an innovative communication scheme, ultra narrow band modulation is attracting more and more attention. In order to uncover the essence of the technology, asymmetric binary x shift keying, the general design scheme of UNB, is proposed and studied in this paper as a different modulation scheme from the traditional methods. The general wave function is defined first, and the modulation process is presented, then particular realization of asymmetric BASK, asymmetric BPSK, and asymmetric BFSK were studied. This verified the general characteristics of asymmetric binary x shift keying proposed above as the general modulation format design of UNB technology from the view of modulation essence. On this basis, time domain and frequency characteristics are given by derivation of wave function and PSD equation, and different particular time domain waveforms and PSD are plotted and examined. Next, a general modulation realization is presented, and the modulation and demodulation process are related, which break through the traditional filtering methods. Filter can then be replaced by other signal shaping methods. Finally, demodulation performance formulas of asymmetric binary x shift keying-based ultra narrow band modulation are derived and compared, which can be a base and guide for further modulation study or a trade off for an optimized design of UNB modulation formats.