Capacity Planning of OFDMA Cellular Networks with Decode-and-Forward Relaying

The cellular relay network can provide both coverage extension and capacity enhancement. However, the network in nature requires more complex operation for maintaining each connection because of an increase dimension of node mobility that affects the signal-to-noise ratio (SNR) at each receiver node in the respective link in the relay architecture. As the outage ratio depends on the SNR statistics and the number of connections admitted in the system, admission capacity planning needs to take into account the SNR fluctuations. In this paper, we propose a new method for admission capacity planning in a cellular network using a cooperative relaying mechanism called decode-and- forward. Our approach is based on a new consideration of the randomness of the channel gain in our formulation of the outage ratio. Admission capacity planning is mathematically formulated as an optimization problem that maximizes the accommodation capacity (in number of connections) subject to a constraint that the outage ratio is upper-bounded by a certain threshold value. The simplicity of the problem formulation facilitates its solution in real-time. The proposed planning method provides an attractive means for dimensioning a cellular relay network with cooperative relay nodes.