Interference Channel with an Out-of-Band Relay (2010)
Cached
Download Links
| Citations: | 16 - 2 self |
BibTeX
@MISC{Sahin10interferencechannel,
author = {Onur Sahin and Osvaldo Simeone and Elza Erkip},
title = { Interference Channel with an Out-of-Band Relay},
year = {2010}
}
Share
 |
 |
 |
 |
||
OpenURL
Abstract
A Gaussian interference channel (IC) with a relay is considered. The relay is assumed to operate over an orthogonal band with respect to the underlying IC, and the overall system is referred to as IC with an out-of-band relay (IC-OBR). The system can be seen as operating over two parallel interference-limited channels: The first is a standard Gaussian IC and the second is a Gaussian relay channel characterized by two sources and destinations communicating through the relay without direct links. We refer to the second parallel channel as OBR Channel (OBRC). The main aim of this work is to identify conditions under which optimal operation, in terms of the capacity region of the IC-OBR, entails either signal relaying and/or interference forwarding by the relay, with either a separable or non-separable use of the two parallel channels, IC and OBRC. Here “separable” refers to transmission of independent information over the two constituent channels. For a basic model in which the OBRC consists of four orthogonal channels from sources to relay and from relay to destinations (IC-OBR Type-I), a condition is identified under which signal relaying and separable operation is optimal. This condition entails the presence of a relay-to-destinations capacity bottleneck on the OBRC and holds irrespective of the IC. When this condition is not satisfied, various scenarios, which depend on the IC channel gains, are identified in which interference forwarding and non-separable operation are necessary to achieve optimal performance. In these scenarios, the system exploits the “excess capacity” on the OBRC via interference forwarding to drive the IC-OBR system in specific interference regimes (strong or mixed). The analysis is then turned to a more complex IC-OBR, in which the OBRC consists of only two orthogonal channels, one from sources to relay and one from relay to destinations (IC-OBR Type-II). For this channel, some capacity resuls are derived that parallel the conclusions for IC-OBR Type-I and point to the additional analytical challenges.
Keyphrases
out-of-band relay interference forwarding interference channel signal relaying orthogonal channel ic-obr type-i constituent channel gaussian relay channel direct link ic-obr type-ii basic model capacity resuls optimal operation obr channel non-separable use overall system ic-obr system main aim separable operation gaussian interference channel orthogonal band additional analytical challenge optimal performance specific interference regime second parallel channel relay-to-destinations capacity bottleneck parallel interferencelimited channel capacity region complex ic-obr independent information parallel channel excess capacity ic channel gain various scenario separable refers standard gaussian ic non-separable operation
