An investigation into the poly-signal date transmission for land mobile radio systems.

Abstract

From the examination of the channel characteristics experienced in the mobile radio environment, it is apparent that the development of data transmission based upon non-binary systems as an alternative to commonly used binary methods is long overdue. A poly-signal modem has emerged from such a design consideration which is unconventional by virtue of its use of the time/frequency parameters available. Because of the complication of modelling the mobile channel one poly-signal scheme with particular advantage was chosen for analysis and the final design compared with a conventional binary system both in laboratory simulations, and also by field trials. It has been shown that under multipath fading conditions, the poly-signal modem maintains a probability of error curve which is normally associated with white noise interference, while binary error curves are modified to a simple function. The two error curves diverge resulting in an apparent increasing improvement for the poly-signal system as bit error rate reduces. For a bit error rate of 10-5 a 10 dB signal to noise ratio advantage is achieved with the new modem compared with the binary, when both operate at 600 bits per second. The improvement is a result of the immunity the poly-signal scheme has to time dependent interference.

Date of Award	1982
Original language	English
Awarding Institution	University of Bath