| Summary: | A project report submitted to the Faculty of Engineering, University of the
Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the
degree of Master of Science in Engineering. === This project report examines the performance of three VLSI U-interface implementations
satisfying the requirements of Basic Access on an ISDN.
The systems evaluated are the Intel 89120,Siemens PEB2090 and STC DSP144, operating
on 2BIQ, MMS4J and SU32 line codes respectively.
Before evaluating the three abovementioned systems, a review of the underlying principles
of U-interface technology is presented. Included in the review are aspects of transmission
line theory, line coding, echo-cancellation, decision feedback equalisation, and pulse density
modulation. The functional specifications of the three systems are then presented followed
by a practical evaluation of each system.
As an aid to testing the transmission systems, an evaluation board has been designed and
built. The latter provides the necessary functionality to correctly activate each system, as
well as the appropriate interfacing requirements for the error-rate tester.
The U-interface transmission systems are evaluated on a number of test-loops, comprising
sections of cable varying in length and gauge. Additionally, impairments are injected into
data-carrying cables, in order to test the performance of each system in the presence of
noise. The results of each test are recorded and analysed.
Finally, a recommendation is made in favour of the 2BIQ U-interface. It is shown to offer
superior transmission performance, at the expense of a slightly higher transmit-power level. === Andrew Chakane 2018
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