Generalized Area Spectral Efficiency of Wireless Ad-hoc Networks over Rayleigh Fading

Jun Zhu, Lei Zhang, Hong-Chuan Yang, and Mazen O. Hasna



Abstract :Generalized area spectral efficiency (GASE) was introducedas a metric to quantify the spectral utilization efficiency ofwireless transmissions. Unlike other performance metrics, GASEtakes into account the spatial property of wireless transmissions.In this paper, we extend the research on GASE from link levelto network level. In particular, we consider a wireless ad-hoc networkwith Poisson distributed nodes. We take into account the cochannelinterference and derive the generic closed-form momentgenerating function (MGF) expression of aggregate interferencein such network. With the interference statistics, we calculate theergodic capacity, affected area, and GASE of the network overRayleigh fading channels. Furthermore, we analyze the effect ofcarrier sense multiple access with collision avoidance (CSMA/CA)mechanism on the GASE performance of such network. Finally,we propose a new cognitive paradigm that allows the secondarytransmitters that are located outside the primary affected area totransmit. With this paradigm, we can achieve high ergodic capacitywhile effectively utilizing the space-spectrum resource of primarynetwork. Besides, through mathematical analysis and numericalexamples, we show that GASE provides a new perspective on transmissionpower selection and secondary network optimization.​ 

Index terms :Aggregate interference, ergodic capacity, Poisson point process, Rayleigh fading.