Digital systems have been the cornerstone of modern communications. They are not always robust to changes in channel conditions, however, and require the transmission of long data blocks to achieve their full potential, which can translate to substantial delays and high encoding/decoding complexity. These problems can be alleviated by the use of end-to-end analog encoders, which directly process the acquired samples using a non-linear transformation whose output is transmitted directly through the channel after proper modulation. For the same performance, these schemes claim greater robustness and feature lower encoding/decoding complexity than traditional digital systems. In exchange, analog systems are less flexible and more difficult to design than their digital counterparts. This project aims at closing this gap by systematically developing low-latency, low-complexity analog schemes that at the same time are robust, flexible and easy to design.
Specifically, this project investigates the application of very novel developments in the field of analog joint source-channel coding for point-to-point and multiterminal communications, considering the case in which temporal or spatial correlations are present in the sources of interest, and studying practical applications in image and video coding. Correlations existing in the original sources may be lost when digital schemes are utilized, therefore degrading the end-to-end system performance, something which is less likely to occur in the proposed analog joint source-channel coding framework. This, together with the robustness of analog schemes to channel variations, while requiring less processing complexity and much shorter block lengths, would make analog coding an excellent candidate to meet the ever growing requirements of modern communications systems if some of the open research problems considered in this proposal, such as the development of analog rate compatible codes capable of achieving any desired rate, are solved.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
