초록 ▼

A system for mitigating the effect of fading in a digital communication system. Deep signal nulls occur when signals from multiple paths are precisely aligned in amplitude and phase canceling the signal at the receiving antenna and creating a fade. In an indoor system, moving either transmitter or r

A system for mitigating the effect of fading in a digital communication system. Deep signal nulls occur when signals from multiple paths are precisely aligned in amplitude and phase canceling the signal at the receiving antenna and creating a fade. In an indoor system, moving either transmitter or receiver a short distance can shift a fade away from the frequency of interest. This invention provides an actual or perceived movement of an antenna such that the effects of fading can be averaged over a time interval. The signal processing capability of modern digital transceivers can correct errors due to the time varying fades using the present invention. Thus, a dual-antenna element using the system of this invention can provide diversity receive and transmit paths to maintain capacity. The present invention may also provide improved capacity to due enhanced stability in power control.

대표청구항 ▼

In a code division multiple access (CDMA) communication system in which system users communicate information signals with other system users through a base station using CDMA communication signals spread upon a carrier signal, said base station having an antenna system comprising: a set of antenna e

In a code division multiple access (CDMA) communication system in which system users communicate information signals with other system users through a base station using CDMA communication signals spread upon a carrier signal, said base station having an antenna system comprising: a set of antenna elements each having two antennas spaced apart by less than a wavelength of said carrier signal; a time variant phase shifting means, disposed between each of said two antennas of each of said antenna elements, for varying phase at a selected rate between said two antennas of each of said antenna elements; and signal distribution means for coupling CDMA communication signals between said base station and said set of antenna elements.