Title :
Analysis of CDMA signal spectral regrowth and waveform quality
Author :
Aparin, Vladimir
Author_Institution :
QUALCOMM Inc., San Diego, CA, USA
fDate :
12/1/2001 12:00:00 AM
Abstract :
Closed-form expressions for the spectral regrowth and waveform quality of a reverse-link code divison multiple access (CDMA) signal passed through a weakly nonlinear circuit are derived using the power series and statistical methods. The third-order nonlinearity is expressed in terms of IP3 to include the memory effects of the circuit in-band and out-of-band reactances. The analysis is based on a time-domain model of the signal that gives more accurate distortion estimates than the widely used Gaussian approximation. The model is used to derive the probability density function and other statistical properties of the CDMA signal to compare them to the Gaussian noise properties. Differences in statistics and distortions of OQPSK and QPSK modulated signals are discussed
Keywords :
Gaussian noise; cellular radio; circuit noise; code division multiple access; electric distortion; nonlinear network analysis; probability; quadrature phase shift keying; radio transmitters; spectral analysis; statistical analysis; time-domain analysis; CDMA signal; CDMA signal spectral regrowth; CDMA waveform quality; Gaussian approximation; Gaussian noise properties; IP3 expression; OQPSK modulated signals; QPSK modulated signals; circuit in-band reactance; circuit out-of-band reactance; closed-form expressions; distortion estimates; distortions; memory effects; power series; probability density function; reverse-link CDMA signal; reverse-link code division multiple access signal; spectral regrowth; statistical methods; statistical properties; third-order nonlinearity; time-domain model; waveform quality; weakly nonlinear circuit; Closed-form solution; Gaussian approximation; Gaussian noise; Multiaccess communication; Nonlinear circuits; Nonlinear distortion; Probability density function; Signal analysis; Statistical analysis; Time domain analysis;
Journal_Title :
Microwave Theory and Techniques, IEEE Transactions on
