Patent ID: 7103375
Filing Date: 2006-09-05
Classification: H04B

Abstract:
1. A method of multipath signal receiving in a CDMA mobile communications system, where the input signal of base station, BS, is an additive mixture of user signals and noise, where a signal of every user being a collection of independently fading path signals comprises the pilot component and info components received via the corresponding pilot and info channels, the amounts of info channels per user and data transmission rates varying in user info channels, comprising making soft decisions about the info parameters of signals of all the info channels of all the users by compensating the interfering effect of signals of all the paths of pilot and info channels of all the users on each other, the method comprising: a step in which a signal is searched by isolating the paths of maximum power signals from the detected signals of paths, a step in which the complex correlation responses of signals of all the isolated paths of info channels of all the users are formed, a step in which the complex correlated responses of signals of all the isolated paths of pilot channels of all the users are formed, a step in which the complex correlation responses of signals of each path of pilot channel of each user are accumulated within the corresponding accumulation time thus generating averaged complex correlation responses of signals of all the paths of pilot channels of all the users, a step in which the generated complex correlation responses of signals of all the paths of info channels of all the users and all the generated complex correlation responses of signals of all the paths of pilot and info channels of all the users are delayed so that while compensating their interfering effect on each other the estimates of this interfering effect be formed, a step in which the soft decisions about the info parameters of signals of all the info channels of all the users are formed successively in L iterations, where L—the integer, greater than or equal to 1, where at each iteration the estimates of the interfering effect of signals of all the paths of pilot channels of all the users on each other are formed and this interfering effect is compensated in the averaged complex correlation responses of signals of all the paths of pilot channels of all the users thus forming more accurate complex correlation responses of signals of all the paths of pilot channels of all the users, a step in which the estimates of the interfering effect of signals of all the paths of pilot channels of all the users on the signals of all the paths of info channels of all the users are made and this interfering effect is compensated in complex correlation responses of signals of all the paths of info channels of all the users thus forming more accurate complex correlation responses of signals of all the paths of info channels of all the users, a step in which the estimates of the interfering effect of signals of all the paths of info channels of all the users on the signals of all the paths of pilot channels of all the users are made and this interfering effect is compensated in more accurate complex correlation responses of signals of all the paths of pilot channels of all the users thus producing the estimates of complex envelopes of signals of all the paths of all the users, a step in which the soft decisions about the info parameters of signals of all the info channels of all the users are formed successively through P a step in which more accurate complex correlation responses of signals of all the paths of each info channel of each users, p being equal to one, or the complex correlation responses of signals of all the paths of info channels of the (p−1)-th stage users, p being greater than one, are combined using the estimates of complex envelopes of signals of all the user paths thus forming soft decisions about the info parameters of signals of info channels of the p-th stage users, a step in which out of the generated soft decisions K a step in which the estimates are made of the interfering effect of signals of all the paths of user info channels, corresponding to the selected soft decisions about the info parameters of signals of user info channels, on the remaining signals of all the paths of user info channels on which the final decision has not yet been made by this stage, a step in which this interfering effect is compensated in the remaining more accurate complex correlation responses of signals of all the paths of info channels of users, p being equal to one, or in the remaining complex correlation responses of signals of all the paths of info channels of the (p−1)-th stage users, p being greater than one, thus forming complex correlation responses of signals of all the paths of info channels of the p-th stage users, a step in which at the last P a step in which the obtained soft decisions about the info parameters of signals of all the info channels of all the users and the estimates of complex envelopes of signals of all the paths of all the users of the current iteration, except the last one, that are delayed by the time of iteration, are used to generate the estimates of the interfering effect of signals of all the paths of pilot channels of all the users on each other, the estimates of the interfering effect of signals of all the paths of pilot channels of all the users on the signals of all the paths of info channels of all the users and the estimates of the interfering effect of signals of all the paths of info channels of all the users on the signals of all the paths of pilot channels of all the users of the subsequent iteration, a step in which at the first iteration in order to generate the estimates of the interfering effect of signals of all the paths of pilot channels of all the users on each other the averaged complex correlation responses of signals of all the paths of pilot channels of all the users are used, in order to generate the estimates of the interfering effect of signals of all the paths of pilot channels of all the users on the signals of all the paths of info channels of all the users more accurate complex correlation responses of signals of all the paths of pilot channels of all the users are used, in order to generate the estimates of the interfering effect of signals of all the paths of info channels of all the users on the signals of all the paths of pilot channels of all the users more accurate complex correlation responses of signals of all the paths of pilot and info channels of all the users are used, and a step in which the soft decisions about the info parameters of signals of all the info channels of all the users of the last iterations are the output signals for decision making.