This article provides a new formulation for the pairwise error probability for any coherently demodulated system in arbitrarily correlated Rayleigh fading. The novelty of the result is that the error probability expression can be described as a function of the eigenvalues of a "signal"-only matrix. We also provide the relationship between the pole location of the characteristic function and the resulting error probability. This result allows us to approximate and bound the desired probability. A new simple bound on the pairwise error probability is derived that is better than the standard Chernoff bound and asymptotically tight with the signal-to-noise ratio (SNR) to the true probability.

This paper extends the traditional Clarke/Jakes (1968, 1974) model for a frequency flat fading process in a land mobile radio system to facilitate the examination of coherent space-time demodulation systems. The work develops a space-time correlation function using a ring of scatterers model around the mobile unit. The resulting correlation function permits the investigation of a variety of issues concerning base station configurations in space-time systems. The interrelationship of the fading process between the space and the time domain is explored. A detailed example regarding the effects of antenna separation in a receiver diversity system is considered. A set of design rules for interleaving depth and antenna separation in a space-time modem is presented and quantified.

This paper provides a new formulation for the pair-wise error probability for any coherently demodulated system in flat Rayleigh fading. The novelty of the result is that the resulting error rate expression is a polynomial function of the eigenvalues of a 'signal' matrix. This view also enables a simple new asymptotically tight bound on the pair-wise error probability. Examples of single and multiple transmit antenna systems are considered.

This paper examines some of the complexity issues arising in the real time implementation of the symbol timing subsystem of a narrowband wireless modem. The modem prototype has been designed for 4 kHz channels in the 220-222 MHz land mobile band. In an effort to achieve high bandwidth efficiency, the modem architecture employs transmitter diversity, pilot symbol assisted modulation, and trellis coded modulation. An experimental, non-real time system has been implemented and extensively field tested demonstrating bandwidth efficiencies in excess of 3 bits per second per Hz. The work on this project is focused on the real-time implementation of the baseband receiver functions using the Texas Instruments C54/spl times/ fixed point digital signal processor. Here we report on some of the performance/complexity tradeoffs present in the design of a DSP implementation of the digital filter and square symbol timing recovery algorithm.