Title :
Performance of π/4-QPSK transmission for digital mobile radio applications
Author :
Yamao, Yasushi ; Saito, Shigeki ; Suzuki, Hiroshi ; Nojima, Toshio
Author_Institution :
NTT Radio Commun. Syst. Lab., Yokosuka, Japan
Abstract :
A power and spectrum efficient 4-PSK (phase shift keying) transmission system for the next-generation high-capacity mobile radios is presented. Two types of 4-PSK modulation scheme, QPSK (quadrature PSK) and π/4-shift QPSK, are compared from the viewpoints of spectrum efficiency, transmission performance, and implementation for mobile units. The transmission system employs a newly developed high-efficiency linear power amplifier and a two-branch postdetection selection diversity scheme. Its performance is examined by using an adaptive carrier tracking demodulator (ACT) and a differential demodulator (DD). Experimental results show that the transmission system employing π/4-shift QPSK with ACT or DD can achieve efficient power spectrum utilization
Keywords :
demodulators; digital radio systems; diversity reception; mobile radio systems; phase shift keying; power amplifiers; spectral analysis; π/4-QPSK transmission; QPSK; adaptive carrier tracking demodulator; differential demodulator; digital mobile radio applications; high-efficiency linear power amplifier; quadrature PSK; spectrum efficiency; transmission performance; two-branch postdetection selection diversity scheme; Bit error rate; Demodulation; Frequency modulation; ISDN; Land mobile radio; Phase shift keying; Quadrature phase shift keying; Radio transmitters; Rayleigh channels; Working environment noise;
Conference_Titel :
Global Telecommunications Conference and Exhibition 'Communications Technology for the 1990s and Beyond' (GLOBECOM), 1989. IEEE
Conference_Location :
Dallas, TX
DOI :
10.1109/GLOCOM.1989.64011
