Performance evaluation of non-linear transmit power amplifiers for North American digital cellular portables

This paper discusses the system performance degradation resulting from using a non-linear transmit power amplifier (PA) in a North American digital cellular (NADC) portable radio. The NADC portables require a linear power amplifier for the spectrally efficient linear modulation scheme, /spl pi//4-DQPSK. It is well known that these PA's can exhibit non-linear characteristics that degrade system performance. System degradation is measured using bit error rate (BER) as the figure of merit. The PA is modeled by its AM-AM and AM-PM characteristics; the receiver architecture contains the simple, yet robust, differential detector. Simulation results are presented for additive white Gaussian noise (AWGN), Rayleigh fading, and frequency selective fading environments, and compared to results for a truly linear PA. In addition, PA spectral regrowth is discussed as well as the potential use of a linearization technique to compensate for the PA effects. >

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

[2]  Larry J. Greenstein,et al.  Performance Analysis of Digital Radio Links with Nonlinear Transmit Amplifiers , 1987, IEEE J. Sel. Areas Commun..

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

[4]  Henry Ludwig Kazecki,et al.  Digital cellular modem field results , 1992, [1992 Proceedings] Vehicular Technology Society 42nd VTS Conference - Frontiers of Technology.

[5]  Adel A. M. Saleh,et al.  Frequency-Independent and Frequency-Dependent Nonlinear Models of TWT Amplifiers , 1981, IEEE Trans. Commun..

[6]  S. Seidel,et al.  900-MHz multipath propagation measurements for US digital cellular radiotelephone , 1990 .

[7]  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.

[8]  A. A. M. Saleh,et al.  Adaptive linearization of power amplifiers in digital radio systems , 1983, The Bell System Technical Journal.

[9]  S. Ono,et al.  Digital cellular system with linear modulation , 1989, IEEE 39th Vehicular Technology Conference.

[10]  Y. Nagata,et al.  Linear amplification technique for digital mobile communications , 1989, IEEE 39th Vehicular Technology Conference.