Multiple Cochannel Interferers Research Articles

Performance evaluation of Rayleigh and log-normal GMSK signals in the presence of cochannel interference

The paper presents the results of a software study of multiple cochannel interferers in a digital system, employing Gaussian minimum shift keying (GMSK) modulation with a bandwidth data rate product BbT = 0.3. The bit-error rate (BER) performance was determined in a Rayleigh and log-normal fading environment typically encountered in mobile radio systems. It has been shown that the error rate is independent of the number of interferers present when the total S/I ratio of up to 6 interferers are considered. Additional performance measures were investigated such as block-error rates, the probability, P(m,n) of having m errors in a block of length n, burst and gap-length distributions. These measures have shown that the interference causes errors to occur in a more bursty manner than Gaussian noise.

Error probability of coherent PSK and FSK systems with multiple cochannel interferences

The symbol error probability of binary and quaternary CPSK and binary CPSK systems with multiple cochannel interferences and Gaussian noise is investigated. Numerical results obtained by using the Monte Carlo method are presented as an example.

Symbol error rate curves for M-QAM signals with multiple cochannel interferers

A recursive algorithm for determining the probability of symbol error in an M-QAM system, subject to multiple-cochannel interferers, is presented. In particular, a recursive formula is derived for determining the symbol-error-rate (SER) of an M-QAM system subject to both multiple-sinusoidal and similar, independent QAM interferers. The result is expected to prove useful in the analysis of such systems exposed to ever-increasing interference. >

Outage probability calculations for multiple cochannel interferers in cellular mobile radio systems

The calculation of outage probability is discussed in relation to cochannel interference problems inherent in mature cellular radio systems. Outage probability equations for coverage only and for single cochannel interferer situations are reviewed briefly, and examples of the application of these results to the estimation of the service area of a typical cellular base station are given. An analytical technique for multiple uncorrelated interferers in a Rayleigh fading environment is presented and the effect of several cochannel Rayleigh interferers on the service area of a cellular base station is examined.

Error rate performance of binary DPSK system with multiple co-channel interference in land mobile radio channels

The error rate performance of a binary differentially encoded phase-shift keying (DPSK) system in the presence of both thermal noise and multiple co-channel interferers is theoretically analyzed in the fast Rayleigh fading environment encountered in the typical UHF or microwave land mobile radio channels. The main objective is to show the additional degradation of an error rate of a binary DPSK system when undesired multiple co-channel M-ary DPSK interferers are virtually generated in a practical land mobile radio channel. The error probabilities are presented by a simple closed form as a function of noise correlation, interferer correlation, the number of interferers, M-ary modulating phase of interferer, Doppler frequency, carrier-to-noise (CNR) and carrier-to-interference (CIR) average power ratios.

Detection in the presence of spherically symmetric random vectors

A random n -vector X=(X_{1}, \cdots , X_{n}) is said to be spherically symmetric (SS) if its joint characteristic function (CF) can be expressed as a function of the quadratic form u \rho u \prime , where u = (u_{1}, \cdots , u_{n}) and \rho is an n \times n positive definite matrix. The investigation in this paper is concerned with the properties of such vectors and some detection problems involving them. We first prove a theorem characterizing the form of SS random vectors X and use it to find the form of the probability density functions (pdf's) of X and of X + N , where N \sim {\cal N (0, \sigma^{2}I) is an independent Gaussian vector and I is the identity matrix. Applying these results we look at the problem of detecting a known signal vector in the presence of X + N when \rho =I . For the k -ary detection problem we present two conditions under which the minimum distance receiver is optimum. Lastly, we discuss an application of our findings to the problem of coherent detection of binary phase-shift keyed (PSK) signals in the presence of multiple co-channel interferences and white Gaussian noise.

Binary PSK Error Probabilities with Multiple Cochannel Interferences

Exact error probabilities are given for a binary phase-shift-keyed (PSK) signal which is transmitted over a nondistorting channel, but additively corrupted by Gaussian noise and cochannel interference. Both coherent detection and quasicoherent (noisy reference) detection are considered. The analysis admits a wide class of interferences, but numerical results are limited to interferences modeled by a sum of randomly phased sinusoids. This includes most extraneous analog frequencymodulation (FM), phase-modulation (PM), or digital PSK signals, or combinations of the same which are cochannel with the desired PSK signal.