Frequency-domain detection of OQPSK signals with quasi-constant envelope and high spectral efficiency

ABSTRACT

In this paper, we consider SC-FDE schemes (Single Carrier with Frequency-Domain Equalization) employing OQPSK (Offset Quaternary Phase Shift Keying) signals with quasi-constant envelope. To allow high spectral efficiency, different frequency channels are separated by the symbol rate, regardless of their bandwidth (which is much higher than the symbol rate for quasi-constant envelope OQPSK signals), and we consider a multi-channel frequency-domain receiver with ACI (Adjacent Channel Interference) suppression. Our performance results show that it is possible to have high spectral efficiency with quasi-constant envelope OQPSK signals. This technique is especially interesting for the uplink of future broadband wireless systems since we can employ low-cost, grossly nonlinear power amplifiers at the mobile terminals and almost all signal processing is shifted to the base station.

References

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Index Terms

• Computing methodologies

  • Modeling and simulation

    • Simulation theory

      • Systems theory

• Information systems

  • World Wide Web

    • Web applications

      • Internet communications tools