Interference channels with half-duplex source cooperation

Interference channel;Source cooperation;Half duplex;Cognitive channel

Wu, Rui ; Viswanath ; Pramod

关键词: Interference channel;    Source cooperation;    Half duplex;    Cognitive channel;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/24136/Wu_Rui.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

The performance gain of allowing half-duplex source cooperation is studied for Gaussian interference channels.The source cooperation is in-band, meaning that each source can listen to the other source's transmission, butthere is no independent channel between the sources; half-duplex assumes that, at each time instant, thesources can either transmit or listen but cannot do both. This assumption differs from some previous works on sourcecooperation. When the cooperation is bidirectional and the channel gains are symmetric, the sum capacity ischaracterized within a constant. When the cooperation is unidirectional, from the primary to the secondary,it is essentially a cognitive channel. By requiring the primary to achieve a rate at most a constant fromits link capacity, the best possible rate for the secondary is characterized within a constant. A generalcoding scheme is proposed for this type of channel. In the first step, only one source transmits and the othersource listens. The active source can send data to its destination, share information with the other nodes, orrelay data from the other source to the other destination. In the second step, both sources transmit. The sharedinformation from the previous step and the interference channel together can be viewed as a virtual channel.On this virtual channel, the sources can do beamforming for the shared messages, and the destinations can partiallycancel the interference, achieving better rates compared with the original interference channel.