Title :
Radio channel structure for QPSK digital mobile radio
Author :
Adachi, F. ; Mori, M. ; Ooi, T.
Author_Institution :
Radio Commun. Syst. Lab., NTT, Kanagawa, Japan
Abstract :
Experiments on QPSK (quadrature phase-shift keying) signal transmission and 8 kb/s TC-WVQ (transform coding with weighted vector quantization) speech coding are presented. Computer simulation of the TC-WVQ speech codec has shown that the subjective quality is comparable to that of 5-bit log PCM (pulse code modulation) at a channel bit error rate of 10-2. Computation complexity can be greatly reduced compared with that of CELP. A proposed channel structure is presented for implementation in a frequency-efficient digital mobile radio system. With QPSK and 8 kb/s TC-WVQ speech codecs, such a digital mobile radio system is as frequency-efficient existing analog systems
Keywords :
codecs; digital radio systems; encoding; mobile radio systems; phase shift keying; telecommunication channels; voice communication; 8 kbit/s; QPSK digital mobile radio; TC-WVQ speech codec; computational complexity; frequency-efficient; quadrature phase-shift keying; radio channel structure; speech coding; transform coding; weighted vector quantization; Computer simulation; Frequency; Land mobile radio; Phase shift keying; Pulse modulation; Quadrature phase shift keying; Speech codecs; Speech coding; Transform coding; Vector quantization;
Conference_Titel :
Vehicular Technology Conference, 1989, IEEE 39th
Conference_Location :
San Francisco, CA
DOI :
10.1109/VETEC.1989.40078
