Multichannel analysis for uplink heterogeneous cellular networks with flexible cell association

In this paper, an analytical framework is developed to evaluate the uplink outage and spatial blocking performance in a multichannel heterogeneous cellular network. A weighted uplink cell association criterion and random channel reuse scheme are integrated in the considered model. The spatial locations of base stations (BSs) per tier as well as the users (UEs) are modelled as independent Poisson point processes. Because of the maximum transmit power constraint, a UE is allowed to communicate with its serving BS only when it has sufficient transmit power to support full channel inversion. With the aid of stochastic geometry, uplink spatial blocking and outage probability are respectively derived, which are validated to be quite close to the true distributions by extensive simulations. Thus, the theoretical analysis developed in this paper is valid. Then, the effect of network parameters, such as weighted factor, power cut-off threshold, and channel reuse factor, can be evaluated by quickly closed-form expressions rather than error-prone system-level simulations.