| 1: Input: pre-processing SINRs of N users: set n=0, R = 0.2: Constructing and initialising the tree topology model; the number of multiplexed users in NOMA system is equal to the number of layers.3: Branch and node settings. Each branch represents the possible power allocation ratio for each user; each node corresponds to a possible power allocation ratio combination up to the nth layer.4: Intra-stage processing; for each node in the current stage, calculate the sum rate of each node in the current and previous stage. For each level, only keep the node with the largest sum rate. The other nodes are considered redundant and discarded to reduce computational complexity.5: Processing for the last stage. The branch number in level n equals to the number of nodes kept in stage N-1.6: For the last stage, βn equals to
1 - \sum\nolimits_{i = 1}^{n - 1} {\beta _i}
. The branch number in stage N equals to the number of nodes kept in stage N-1. The node which has the largest sum rate in each layer is considered to be the survival node.7: Trace back from the node which is determined in Steps 5 and 6, and then output the combination of power allocation ratio. |
