Ozgur Dural

Reduced Complexity and Close to Optimum Performing Receivers for Continuous Phase Modulation

Date: Date: August 15th, 2002

Abstract:

With the ever increasing demand on bandwidth and power in communication systems, continuous phase modulation (CPM), which is a digital modulation scheme, has attracted great deal of attention since it is both bandwidth and power efficient. CPM is also constant envelope which allows to use of low cost power amplifiers. The invention of turbo codes has shown that iterative decoding schemes can perform exceptionally well in low signal-to-noise ratios. This fact inspired the use similar schemes with serially concatenated codes and finally concatenation of convolutional codes and CPM.

In this dissertation, we first develope the new signal space representation of CPM signals. Next, we propose a receiver which is reduced in complexity and close to optimum in performance. We also show that our receiver outperforms another receiver which provides similar reduction in complexity. We explain the application of iterative demodulation and decoding to serial concatenation of convolutional codes and CPM in detail. We obtain upper bounds on the performance of this application in the additive white Gaussian and fading channels by applying the standard union bound and the improved upper bounding techniques.

Thesis Committee:
Prof. John Proakis, Superviser
Prof. Masoud Salehi
Dr. Zoran Zvonar