Advanced Techniques for Continuous Phase Modulation
Project Award Date: 12-17-2007
Continuous Phase Modulation (CPM) is a communication format that continues to play a significant role in wireless communications. Very transmitter friendly, CPM is the modulation of choice in applications where low-cost circuitry and transmitter power efficiency are essential (e.g., Bluetooth). However, CPM can be challenging to work with on the receiving end. Therefore, most of the attention given to CPM is focused on improving aspects of receiver performance.
ITTC researchers will establish the viability of CPM in new applications. One example proposed is BLAST-type MIMO CPM. A number of fundamental questions are still open about such schemes, regarding their capacity, performance, and complexity. Another example proposed is concatenated coded CPM with iterative (turbo) detection. This application is still in its infancy, and a number of questions remain open regarding code design (LDPC, convolutional, etc.) and the best reduced-complexity decoding algorithms (coherent and noncoherent).
Researchers will advance CPM in its existing applications. Receiver synchronization is a challenge that continues to trouble CPM in some cases. One method of simplifying the synchronization problem is to use noncoherent detection. ITTC will explore a fundamentally different approach to designing noncoherent detection algorithms for CPM. The main idea is to quantify receiver complexity and performance in terms of real-world measures, and then optimize both at the same time; the result is the algorithm with the least complexity and the best performance. Another proposed area of research is a comprehensive synchronization/detection receiver based on popular Laurent-type models for CPM. Separate bits and pieces of such a receiver have been developed to-date, but a unified study and characterization of such a receiver does not yet exist.
Primary Sponsor(s): Nokia Siemens Networks