초록 ▼

A CDMA demodulating apparatus with an improved interference canceling effect when there are a large number of communicators. A reception signal having a frame configuration in which a pilot signal of a known pattern is inserted between information signals is received from a plurality of communicator

A CDMA demodulating apparatus with an improved interference canceling effect when there are a large number of communicators. A reception signal having a frame configuration in which a pilot signal of a known pattern is inserted between information signals is received from a plurality of communicators. Transmission data of each communicator is demodulated, an interference canceler for estimating is provided in a plurality of stages, in each channel of each stage, a variation of transmission path is estimated in each path to achieve data demodulation and estimation of interference replica. The later the stage, the more error of interference signal replica can be reduced, thereby improving the interference canceling effect. An even better effect can be obtained when interference canceling is performed after detecting a reception level of each channel by summation of reception power of each path of each channel, and channel ranking is determined in the order of higher reception level.

대표청구항 ▼

[ What is claimed is:] [1.] A CDMA (Code Division Multiple Access) demodulating apparatus for use in a CDMA communication system that performs spreading information data by a spreading code faster than an information rate to a wideband signal and the wideband signal is transmitted to achieve multipl

[ What is claimed is:] [1.] A CDMA (Code Division Multiple Access) demodulating apparatus for use in a CDMA communication system that performs spreading information data by a spreading code faster than an information rate to a wideband signal and the wideband signal is transmitted to achieve multiple access transmission, wherein a pilot symbol of know pattern is received to estimate channel variation, individual reception signals received through a plurality of channels are compensated by the estimated channel variation, and the compensated reception signal is demodulated to reproduce the information data, comprising:a correlation detector using a spreading code as a spreading code replica synchronized with a reception timing of each path of each of the channel for correlation detection of the spreading code replica with the reception signal of each path;a received level detector for determining a sum of a reception power of a corresponding path of said correlation detector and detecting a desired wave reception signal level;a channel ranking unit for controlling order of demodulation of the user according to the reception signal level of each user detected by said received level detector; andan interference canceler of a plurality of stages for making interference canceling according to a control signal outputted from said channel ranking unit, in each of the plurality of stages, making estimation of channel variation using the pilot symbol on each channel, compensating the reception signal of the channel by the estimated channel variation, and respreading the compensated reception signal to produce an interference signal replica.