City Research Online

Abstract

Electronic filters are one of the basic elements in a communication system. In recent years, digital filters have attracted much attention due to many reasons, such as stability, flexibility, speed, cost, etc. One major problem with digital filters is the effects of finite wordlength. Wave Digital Filters (WDFs) were first introduced by Fettweis in 1971 to reduce these effects. However, the main drawback of WDFs is the hardware complexity when compared with the conventional cascade of second order sections. In general, the implementation of WDFs depends on how efficient the 2-port, 3-port parallel and 3-port serial adaptors are implemented. Therefore, one way of approaching the hardware complexity of WDFs is to consider the VLSI implementation of WDF adaptors.

In this thesis, bit-level systolic arrays are developed for the implementation of WDF adaptors. The systolic arrays developed are very suitable for the VLSI implementation of WDFs. A 2-port prototype systolic adaptoi' has been constructed and tested fully to prove the correctness of the design. Also, a universal systolic adaptor is designed which can be programmed to realise 2-port, 3-port parallel and 3-port serial adaptors. The number of transistors required to implement the adaptors in CMOS technology and the speed
of the adaptors has also been estimated.

Also in this thesis, a complete software package has been developed which can be used for the synthesis and finite wordlength design of WDFs based on three well known reference filters, i.e unit element, lattice and LC-ladder filters. Software tools are also developed for the analysis and simulation of the filters designed. The simulation program allows the simulation of the systolic WDFs .

Many examples have been considered to illustrate the performance of the design programs and the systolic WDFs. From the example, it will be shown that the finite wordlength design program can be used t o minimize the number of bits used to represent the filter coefficients. Also, it will be seen that a small reduction in the number of bits for the coefficients would exponentially reduce the complexity, and consequently the number of transistors, of a systolic WDF .

Publication Type:	Thesis (Doctoral)
Subjects:	Q Science > QA Mathematics > QA75 Electronic computers. Computer science Q Science > QA Mathematics > QA76 Computer software T Technology > T Technology (General)
Departments:	School of Science & Technology > Engineering School of Science & Technology > School of Science & Technology Doctoral Theses Doctoral Theses

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