Oct 09, 2015: 11:00 am
Location: UC San Diego, Atkinson Hall, Room 4004
Next-generation wireless networks aim to enable order-of-magnitude increases in connectivity, capacity, and speed. Such a goal can be achieved in part by utilizing larger frequency bandwidth or deploying denser base stations. However, as the number of wireless devices is exploding, it is inevitable that multiple devices communicate over the same time and spectrum. Consequently, mitigating the interference in concurrent transmission becomes the key challenge to future wireless systems. Existing methods either avoid interference by coordinating among senders to transmit in orthogonal time/frequency dimensions, or ignore interference by treating it as part of the noise. Information theory tells us that optimal performance is achieved instead by simultaneous decoding of both desired and interfering signals, exploiting digital structures of these signals. Due to its high computational complexity, however, simultaneous decoding has not been implemented in practice.
In this talk, I will present two practical coding schemes that achieve the performance of simultaneous decoding at low complexity. The first scheme builds on recently invented polar codes. The recursive structure and the polarization principle that underlie polar codes allow an efficient implementation of simultaneous decoding. The second scheme circumvents the difficulty of simultaneous decoding by designing a point-to-point coding scheme that achieves the same performance. This allows us to leverage commercial off-the-shelf codes to implement simultaneous decoding with minimal changes to existing systems. Simulation results demonstrate a significant performance improvement upon existing methods when interference is strong.
Lele Wang received the B.E. degree in Electrical Engineering at Tsinghua University, Beijing, China. She is receiving the Ph.D. degree in Electrical and Computer Engineering at University of California, San Diego and is joining Tel Aviv University and Stanford University as a joint postdoc researcher. Her research focus is on information theory, coding theory, and communication theory. She is a recipient of the 2013 UCSD Shannon Memorial Fellowship and the 2013-2014 Qualcomm Innovation Fellowship.