Revisiting Parallel Channels
Event details
| Date | 24.06.2010 |
| Hour | 14:15 |
| Speaker | Prof. Babak Hossein Khalaj, Sharif University of Technology |
| Location | |
| Category | Conferences - Seminars |
Parallel channels appear in wide range of communication system applications, in addition to optics and electromagnetic propagation. Two main issues arising when dealing with parallel channels is, first, how to identify the number of available parallel channels, and second, how to exploit the existence of such channels in an optimum way. The first question involves finding the so-called Degrees of Freedom of the channel. This number, for example, corresponds to the number of sub-carriers in an OFDM system, the rank of channel matrix for a MIMO system, the number of independent time slots in a fast fading scenario, and the number of independent routes between source and destination in a communication network. After identifying the number of parallel channels, the second question has been traditionally addressed by the Waterfilling algorithm which optimizes the transmission rate over different sub-channels for a given total transmission power. However, the solution is not trivial when other practical factors such as delay come into consideration. Another important question also arises when diversity and multiplexing trade-offs are taken into account. Extending such ideas to multiuser scenarios has also been addressed through schemes such as Interference Alignment. In this talk, after revisiting the main concepts behind parallel channels, we will discuss new ideas related to this topic and finally, present some open problems in this field.
Prof. Khalaj's homepage
Practical information
- General public
- Free