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 |
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Original language | English |
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Awarding Institution | |
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An investigation into the poly-signal date transmission for land mobile radio systems.
Holland, P. G. (Author). 1982
Student thesis: Doctoral Thesis › PhD