Patent ID: 8798025
Filing Date: 2014-08-05
Classification: H04B,H04L

Abstract:
1. A frequency division multiplexed, continuous phase modulation (FDM-CPM) multi-user detector comprising: a processor for executing instructions stored in a memory, and the processor for operating a computational complexity that is related non exponentially to a number of users, the processor of the FDM-CPM multi-user detector being further configured to: jointly detect symbols of multiple users in a received multi-user FDM-CPM signal; and determine, from said received multi-user signal, marginal a-posteriori probability mass functions (pmf's) of a time-sequence of CPM states and transmitted symbols of all users, wherein the a-posteriori pmf's of the transmitted symbols are determined by carrying out an iterative message passing process corresponding to a specific factorization of a joint a-posteriori pmf of the transmitted symbols and CPM states, wherein the factorization involves a combined variable representing possible transmitted symbols and CPM states of each user for each symbol time interval, so as to make the iterative message passing process convergent, and wherein the iterative message passing process attains non exponential complexity with respect to the number of users by making an approximation by disregarding multiple access interference (MAI) from at least some of the other users.