Ipr Licensing, Inc.

Tantivy Communications, Inc.

Alton S Keel, Jr

James Arthur Proctor, Jr

Bing Chiang

Kenneth Marvin Gainey

Griffin Keith Gothard

Christopher A Snyder

Douglas Harold Wood

Joe T Richeson

Stefan Haenggi

Mark J Takatz

An Automatic Gain Control (AGC) circuit as used in a digital receiver that utilizes a main loop filter that is of a relatively wide bandwidth. A pre-filter, wideband variance is determined from the input digital signal, and a post-filter, narrowband variance is also determined. The wideband and narrowband variances are then compared to determine if the wideband signal power indicates a variance level that is too great to permit normal loop operation. By reapplying this difference in the power levels to the filter output as needed, such as by a scaling operation, the loss in dynamic range is effectively recovered. In a preferred embodiment, an adjustable gain input amplifier feeds an intermediate frequency (IF) signal to an analog-to-digital converter (ADC). The digitized IF signal is then down-converted to a baseband frequency and subjected to digital filtering. A narrowband sample variance (P) of the digitally filtered (narrowband) data is then determined. A wideband sample variance (P) is also taken from the raw ADC output data over the same period as the time period used for P. In the presence of out-of-band signal components, Pwill be quite different from P. This difference indicates a desired proportional difference in a control voltage or a gain backoff amount.

Narrowband gain control of receiver with digital post filtering

An antenna apparatus, which can increase capacity in a cellular communication system or Wireless Local Area Network (WLAN), such as an 802.11 network, operates in conjunction with a mobile subscriber unit or client station. At least one antenna element is active and located within multiple passive antenna elements. The passive antenna elements are coupled to selectable impedance components for phase control of re-radiated RF signals. Various techniques for determining the phase of each antenna element are supported to enable the antenna apparatus to direct an antenna beam pattern toward a base station or access point with maximum gain, and, consequently, maximum signal-to-noise ratio. By directionally receiving and transmitting signals, multipath fading is greatly reduced as well as intercell interference.

Adaptive antenna for use in wireless communication systems

An antenna apparatus which can increase capacity in a cellular communication system. The antenna operates in conjunction with a mobile subscriber unit and provides a plurality of antenna elements. At least one active antenna element is active and essentially centrally located within multiple passive antenna elements. The passive antenna elements are coupled to selectable impedance components. Through proper control of the passive antenna elements, the cellular communication system directs an antenna beam pattern toward an antenna tower of a base station to maximize gain, and, consequently, signal-to-noise ratio. Thus, optimum reception is achieved during, for example, an idle mode which receives a pilot signal. The antenna array creates a beamformer for signals to be transmitted from the mobile subscriber unit, and a directional receiving array to more optimally detect and receive signals transmitted from the base station. By directionally receiving and transmitting signals, multipath fading is greatly reduced as well as intercell interference. Various techniques for determining the proper phase of each antenna element are accommodated.

Growing community of inventors

Hellam, PA, United States of America

Alton S Keel, Jr