Title :
Modulation methods for PCNs
Author :
Webb, William T.
Author_Institution :
Multiple Access Communications Ltd., Southampton, UK
Abstract :
The interference levels that may be expected for a range of conventional cellular and microcellular clusters used in personal communication networks (PCNs) and personal communication systems (PCSs) are discussed. Simulation results show that for conventional size cells, 32- and 64-level quadrature amplitude modulation (QAM) schemes are preferred for bit error rates (BER) above 1*10/sup -2/, while 4PSK or variable-rate QAM schemes are better for lower BER. For microcells with communications at both 900 MHz and 1.8 GHz, four- or six-cell clusters are advocated, depending on the SNR expected. Based on the expected signal-to-noise ratio (SNR) and interference levels, it is argued that variable-rate QAM schemes are superior to the other modulation schemes considered. For low BERs 4PSK may often provide the best performance, whereas for high BERs, particularly when the SNR is high, 32- and 64-level star QAM are the most suitable.<>
Keywords :
amplitude modulation; cellular radio; personal communication networks; phase shift keying; radiofrequency interference; 1.8 GHz; 32-QAM; 4PSK; 64-QAM; 900 MHz; BER; PCN; SNR; UHF; cellular clusters; four-cell clusters; interference levels; microcellular clusters; modulation methods; personal communication networks; personal communication systems; quadrature amplitude modulation; signal-to-noise ratio; six-cell clusters; variable-rate QAM; Bandwidth; Bit rate; Computer simulation; Equations; Frequency; Intelligent networks; Microcell networks; Personal communication networks; Quadrature amplitude modulation; Speech;
Journal_Title :
Communications Magazine, IEEE
