Capacity Analysis Of Full Duplex Wireless Networks Via Stochastic Geometry

Recently, full duplex wireless communication is realized by advanced physical-layer techniques,thus, a radio can transmit and receive signals on the same frequency simultaneously. Comparedwith half duplex communication, the network throughput can be doubled in a single hop wirelessnetwork. However, it is still an open research topic on throughput gains from full duplexcommunications in large scale wireless networks. To solve this problem, we employed toolsfrom stochastic geometry to analyze network capacity in two types of wireless networks, ad hocnetworks and cellular networks.As for ad hoc networks, the network topology is modeled as a Poisson cluster point processand the aggregate interference is calculated using a shot-noise process. To measure the net-work capacity, the notion of transmission capacity is utilized, which is the maximum successfultransmission throughput in a unit area, subjecting to a constraint on outage probability. Basedon our proposed model, performances of both half and full duplex wireless networks underthree communication scenarios are presented. Firstly, transmission throughput is plotted forthe same network density and transmission rate requirements. Results indicate that full duplexcommunication outperforms half duplex communication in the low transmission rate regionand half duplex communication outperforms full duplex communication in the high transmis-sion rate region. Secondly, under the same network density and the same outage requirement,transmission capacity, i.e. maximum transmission throughput, is presented by increasing thetransmission rate. The results are consistent with transmission throughput in the frst case.At last, fxed transmission rate and outage requirement are set to be the same for half du-plex and full duplex wireless networks. Transmission capacity by maximizing network densityis given. Results show that full duplex transmission capacity is always larger than half du-plex transmission capacity, indicating that full duplex communication outperforms half duplexcommunication via more concurrent transmission opportunities.As for cellular networks, assume full duplex radios installed on base stations, and a newtechnique mutual interference cancelation (MIC) is put forward to combat mutual interferencebetween transmission pairs. Perfect MIC is defned and implemented on base stations for fullduplex cellular network. The Network topology is modeled as two-layer Poisson point processwith two identical density for each layer and the aggregate interference is analyzed followingshot-noise process. Coverage probability and average rate of a typical uplink and downlinkare derived. Comparisons of coverage probability and average rate are conducted between half duplex communications and full duplex communications with/without MIC. Numericalresults are run in two scenarios, zero background noise and nonzero background noise. Inthe zero background noise scenario, coverage probability is expressed in closed-form, and it isindependent with network density. Thus, network capacity gain of full duplex communicationis independent with network density when noise is neglected. In the nonzero noise backgroundscenario, the coverage probability is expressed by closed-form related to Q-function, the tailprobability of the standard normal distribution, when path-loss parameter is4. The numericalresults show that network capacity gain of full duplex communication degrades when networkdensity is increased, which is consistent with the situation in wireless ad hoc network. Moreover,the network capacity gain also degrades when signal to noise ratio (SNR) increases, and isimproved signifcantly when adopting MIC at the base stations. Thus, network capacity gainfrom full duplex communication is very limited and MIC can improve the network capacitygain signifcantly.