Block Modulation with Time-limited Pulse Shaping

In order to achieve the optimal power efficiency, most communication systems adopt band-limited pulse shaping satisfying the Nyquist zero inter-symbol-interference (ISI) criterion. However, in practice, a band-limited pulse must be truncated in the time domain to a few symbol time duration before a transmission, which inevitably introduces ISI in the truncated transmitted waveform. Moreover, after the truncation, the pulse will occupy more than the Nyquist bandwidth and thus the spectral efficiency will degrade with respect to the Nyquist pulsed-modulation. In this thesis, block transmission of time-limited pulse shaping will be developed in order to achieve a high spectral efficiency which can be made arbitrary close to that offered by the ideal Nyquist-pulsed modulation and realizable RRC-pulsed modulation, and provide the same power efficiency (error performance) which is equivalent to that offered by the ideal Nyquist-pulsed modulation, while avoids ISI introduced by the truncation by adopting a time-limited pulse. Specifically, constraints on time-limited pulse are developed to provide desirable power spectrum with a fast sidelobe envelope decaying in the frequency domain and the corresponding pulse family are also proposed. Constraint on precoder of block transmission is developed in conjunction with the prescribed time-limited pulse to guarantee the orthogonality of signaling which is not only able to achieve the best power efficiency which is equivalent to that offered by the ideal Nyquist-pulsed modulation but also maintain decoding complexity low. Furthermore, precoder is designed to reduce peak-to-average power ratio(PAPR) and suppress specific band power while maintaining signaling orthogonal. Based on our analysis, the capacity achieved by the proposed orthogonal precoder is proved to be optimal in the sense that the capacity is maximized subject to an average power constraint. Additionally, block modulation system with band-limited pulse shaping is proposed for the theory completeness. To help the analysis of the block modulation system with band-limited pulse shaping, the spectrum eigenvalues distribution theorem is proposed to relate a pulse shaping to its eigenvalues distribution of the corresponding transfer matrix.