Modems for emerging digital cellular-mobile radio system

Digital modem techniques for emerging digital cellular telecommunications-mobile radio system applications are described and analyzed. In particular, theoretical performance, experimental results, principles of operation. and various architectures of pi /4-QPSK ( pi /4-shifted coherent or differential QPSK) modems for second-generation US digital cellular radio system applications are presented. The spectral/power efficiency and performance of the pi /4-QPSK modems (emerging American and Japanese digital cellular standards) are studied and briefly compared to GMSK (Gaussian minimum-shift keying) modems (proposed for European DECT and GSM cellular standards). Improved filtering strategies and digital pilot-aided (digital channel sounding) techniques are also considered for pi /4-QPSK and other digital modems. More spectrally efficient modem trends for future cellular mobile (land mobile) and satellite communication system applications are also highlighted. >

[1]  S. Sampei,et al.  Rayleigh fading compensation method for 16QAM in digital land mobile radio channels , 1989, IEEE 39th Vehicular Technology Conference.

[2]  N. Nakajima,et al.  A system design for TDMA mobile radios , 1990, 40th IEEE Conference on Vehicular Technology.

[3]  P. D. Morgan,et al.  Use of Four-Level Phase Modulation for Digital Mobile Radio , 1972 .

[4]  John G. Proakis,et al.  Digital Communications , 1983 .

[5]  K. Feher,et al.  Performance evaluation of differential pi /4-QPSK systems in a Rayleigh fading/delay spread/CCI/AWGN environment , 1990, 40th IEEE Conference on Vehicular Technology.

[6]  S. Ariyavisitakul.  Equalization of a hard-limited slowly-fading multipath signal using a phase equalizer with a time-reversal structure , 1990, 40th IEEE Conference on Vehicular Technology.

[7]  K. Feher,et al.  SP-QPSK: a new modulation technique for satellite and land-mobile digital broadcasting , 1990 .

[8]  K. Feher,et al.  Bit error rate performance of pi /4-DQPSK in a frequency-selective fast Rayleigh fading channel , 1991 .

[9]  J. G. Proakis.  Adaptive equalization for TDMA digital mobile radio , 1991 .

[10]  C.-L. Liu,et al.  Noncoherent detection of pi /4-QPSK systems in a CCI-AWGN combined interference environment , 1989, IEEE 39th Vehicular Technology Conference.

[11]  William C. Y. Lee,et al.  Mobile Communications Design Fundamentals , 1986 .

[12]  K. Feher,et al.  A new generation of Rayleigh fade compensated pi /4-QPSK coherent modems , 1990, 40th IEEE Conference on Vehicular Technology.

[13]  Kamilo Feher.  Advanced Digital Communications: Systems and Signal Processing Techniques , 1986 .

[14]  K. Raith,et al.  Capacity of digital cellular TDMA systems , 1991 .

[15]  K. Feher,et al.  pi /4-QPSK modems for satellite sound/data broadcast systems , 1991 .

[16]  Yoshihiko Akaiwa,et al.  Highly Efficient Digital Mobile Communications with a Linear Modulation Method , 1987, IEEE J. Sel. Areas Commun..

[17]  Steven H. Goode,et al.  A comparison of a limiter-discriminator, delay and coherent detection for pi /4 QPSK , 1990, 40th IEEE Conference on Vehicular Technology.

[18]  John H. Lodge,et al.  TCMP-a modulation and coding strategy for Rician fading channels , 1989, IEEE J. Sel. Areas Commun..

[19]  Dariush Divsalar,et al.  Multiple trellis coded modulation (MTCM) , 1988, IEEE Trans. Commun..