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US 5,437,055 AGranted
Antenna system for multipath diversity in an indoor microcellular communication system
AssigneeQUALCOMM Incorporated
InventorCharles E. Wheatley, III
Life of this patent
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AssigneeQUALCOMM Incorporated
InventorCharles E. Wheatley, III
Estimating the term…
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.
In a microcellular digital communication system having one or more mobile transceivers and at least one stationary transceiver with at least one antenna element comprising a set of antennas for sending and receiving a data signal having a carrier frequency propagated between any of said mobile transceivers and said stationary transceiver through a channel having a plurality of paths, a method for limiting the maximum signal fading loss duration in said propagation channel to a predetermined threshold value, said method comprising the steps of:
The method of claim I wherein said modulating step comprises the step of moving the position a first antenna of said set of antennas relative to a second antenna of said set of antennas at said predetermined rate.
A microcellular cellular digital communications system in which information signals are communicated between a fixed location and one or more mobile transceivers, said system comprising:
Dependencies are inferred from the claim text.