Communication & Signal Processing
Exploiting Diversity in Wireless Networks
- Multi-layered schemes in MIMO systems
- OFDM for Cooperative Networks
- Radar Imaging
- 50% Efficient Solar Cells
- Capacity optimization
- Channel coding for non-standard channels with memory
- Exploiting Diversity in Wireless Networks
- Image Compression
- Low-density generator matrix codes
- Message Authentication in Noisy Environments
- Multi-tone blue noise dithering
- Inverse Lithography
- Space-time/frequency coding for MIMO and cooperative communications systems
- Steganalysis of Digital Images and Videos
- Turbo-like codes for distributed source and joint source-channel coding
- Compressive sensing in imaging, sensor networks, and UWB radios
- Lossless Data Compression
Participating graduate students
One important characteristic of wireless communication is that the quality of communication channels varies with time. As a result, some channels are better than others. This effect is called channel diversity. In multihop communication, the effect is similar and is refered to as path diversity. However, since paths are composed of many links, a good path may be far better than a bad path. Hence, potentially there are tremendous benefits to finding and utilizing these good paths. For example, we have found that it is not uncommon to find a good path that is 3000 times better than the typical path. On the other hand, repeated searching can expend resources. This research focuses on the theoretical performance improvements as well as developing practical ways to efficiently exploit multihop diversity.
Jonghyun Kim and Stephan Bohacek, "Exploiting Multihop Diversity Through Efficient Localized Searching with CDMA and Route Metric-Based Power Control," The 9-th ACM/IEEE International Symposium on Modeling, Analysis and Simulation of Wireless and Mobile Systems, 2006.
Stephan Bohacek, "Achievable Performance Improvements Provided by Cooperative Diversity", 4th Intl. Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks, 2006.
Stephan Bohacek, Rick Blum, Len Cimini, Larry Greenstein, Alex Haimovich, "The impact of the timeliness of information on the performance of multihop best-select", Milcom, 2005.