چكيده به لاتين
One of the fundamental problems in the multi-user wireless communication systems is the problem of interference management. Interference alignment (IA) is a promising method to solve this problem. In this method, the space occupied by the interfering signals at each receiver is further reduced and more space is given to the desired signal compared to other interference management methods.
Although interference reduces the data rate, but according to recent research advances, interference can also provide benefits to wireless networks. By considering wireless signals can carry Information and power, interference in the environment can be used for energy harvesting in the receivers. Consequently, interference has two different aspects. On the one hand, affecting the quality of information transmission and on the other hand, can be used for energy harvesting. IA and wireless energy harvesting are commonly investigated separately in research sources. In conventional IA networks, the ultimate goal is to align and then eliminate interfering signals. So that, interference in the environment is not exploited for a particular application, while these signals can be used for energy harvesting.
In this thesis, IA in space dimension and wireless energy harvesting by exploiting interference is investigated jointly in the downlink of a multi-user multiple-input multiple-output (MIMO) two-hop interference channel with multiple data streams. First, an IA based interference management scheme is proposed in the system with different CSI modes and correlation among the antennas for both AF and DF protocols. So that, the IA technique in the first and second hops is adopted to align the interfering signals in each relay and receiver. Then to transfer information and power simultaneously by using the proposed interference management scheme, a power allocation scheme is proposed in the DF protocol to guarantee the amount of harvested power and the quality of received signals. The proposed schemes are analyzed based on average sum rate and average total transmit power. The simulation results show that the proposed scheme provides higher average sum rate than IA in interference channel and it needs less transmitting power to meet the thresholds of the harvested power and the quality of the received signal.
Keywords: Interference alignment, simultaneous wireless information and power transfer (SWIPT), energy harvesting, AF relay, DF relay, imperfect CSI, correlation among the transmit and receive antennas.
