In this project we will use relaying in an effort to overcome one of the main limitations of 60GHz communications – namely its inability to penetrate walls. We will also introduce some new results from network coding theory to improve the efficiency of the transmission. We will make a real world live demonstration of the concept.
To achieve high data rates high transmission bandwidths are required. This is clear from the user bandwidths typically used in 1G, 2G, 3G and 4G cellular namely 25kHz, 200kHz, 5MHz and 20MHz. The largest usable bandwidth available for data services is located around 60GHz and is 6-7GHz wide. Radio communication at such high frequencies has one disadvantage – the radio waves do not propagate through walls and the path-loss is very high. This is also an advantage since it isolates radio links from each other and therefore reduces interference.
In this project we will investigate so-called relaying as a way of overcoming the path-loss disadvantage of to the 60GHz carrier frequency. The scenario is illustrated in the figure below. The two nodes N1 and N2 want to communicate with each other. For instance, N1 could be virtual reality helmet and N2 the access point which connects to a multi gigabit fiber network. Since there N1 and N2 are on different sides of the wall, this is not possible. However, if a relay is inserted as indicated in “R” the signal can now be forwarded by the relay, thereby by-passing the wall. The relay could e.g. be integrated into a light bulb. We will use new techniques based on network coding where the relay transmits signals to the two nodes simultaneously, and multiple antennas are used to further improve link efficiency.
Project manager: Per Zetterberg, KTH
Duration: 2014-01-10 to
Funding: Wireless@kth and project partners (in kind)
Project partners: KTH and Bluewave microsystems
Project website: http://www.kth.se/ees/omskolan/organisation/avdelningar/sp/research/projects/60ghz-bidirectional-relay-demonstrator