Wi-lan Inc.

Cirrus Logic Inc.

Pacific Communication Sciences, Inc.

Rockwell Semiconductor Systems, Inc.

Ensemble Communications, Inc.

Spectrix Corporation

Sheldon L Gilbert

Israel Jay Klein

Kenneth L Stanwood

James F Mollenauer

James E Petranovich

Steven H Gardner

Rami Hadar

Carl Thomas Hardin

Francis James Canova, Jr

Benny Madsen

F Matthew Rhodes

Joseph T Lipowski

Bjorn E Bjerede

Carolyn L Heide

Dennis L Director

A method and apparatus for requesting and allocating bandwidth in a broadband wireless communication system. The method and apparatus includes a combination of techniques that allow a plurality of CPEs to communicate their bandwidth request messages to respective base stations. One technique includes a 'polling' method whereby a base station polls CPEs individually or in groups and allocates bandwidth specifically for the purpose of allowing the CPEs to respond with bandwidth requests. The polling of the CPEs by the base station may be in response to a CPE setting a 'poll-me bit' or, alternatively, it may be periodic. Another technique comprises &#x201c;piggybacking&#x201d; bandwidth requests on bandwidth already allocated to a CPE. Currently active CPEs request bandwidth using unused portions of uplink bandwidth that is already allocated to the CPE. The CPE is responsible for distributing the allocated uplink bandwidth in a manner that accommodates the services provided by the CPE.

Methods and systems for transmission of multiple modulated signals over wireless networks

The present invention is a method and apparatus for reducing co-channel interference. The present invention includes a powerful means for eliminating co-channel interference from base stations in a wireless communication system. The present co-channel interference reducing method and apparatus utilizes frame synchronization between selected time frames (e.g., odd and even time frames) to reduce co-channel interference. Advantageously, the present invention reduces co-channel interference and, thus, allows robust modulation schemes to operate even at worst case line-of-sight (LoS) interference scenarios of 100%. The present invention can also use an uplink/downlink ratio formula to further improve system capacity (i.e., reduce co-channel interference) in ATDD systems. The present inventive method and apparatus can be used in any type of frame based and frame synchronized communication system.

Method and apparatus for reducing co-channel interference in a frame-synchronized wireless communication system

A time sharing method and apparatus for frequency reuse in cellular communication systems. Frequency reuse is enhanced by synchronizing cell transmit/receive base stations in a cellular system to a common time base, and then sharing the available frequencies via allocated time slots. Cells using the same frequency that may interfere with each other are activated only during selected time intervals while same-frequency cells nearby are deactivated. The deactivated cells are then in turn activated while previously activated same-frequency cells nearby are deactivated. The frequency time slots may be of equal length, or longer time slots may be allocated to cells having higher usage rates, as determined in any of a number of ways. The time slots may be mutually exclusive, or may overlap. The time sharing technique of the present invention allows design of cell systems with many reuse patterns. Several particular cell reuse patterns are disclosed that provide good operational characteristics and low co-channel interference. The invention allows the use of a small number of cellular frequencies in a conventional cellular system without significant alteration of the existing system, and is particularly useful in two-way cellular paging systems. Improved reverse link data throughput is achieved via reuse of the reverse frequency channels.

Method and apparatus for frequency reuse in cellular communication systems

Reverse channel reuse scheme in a time shared cellular communication

An adaptive time division duplexing (ATDD) method and apparatus for duplexing transmissions on a communication link in wireless communication systems. Communication link efficiency is enhanced by dynamically adapting to the uplink and downlink bandwidth requirements of the communication channels. Time slots are flexibly and dynamically allocated for uplink or downlink transmissions depending upon the bandwidth needs of a channel. Communication link bandwidth requirements are continuously monitored using sets of pre-determined bandwidth requirement parameters. Communication channels are configured to have either symmetric or asymmetric uplink/downlink bandwidths depending upon the needs of the channel. Channel bandwidth asymmetry can be configured alternatively in favor of the uplink transmissions (i.e., more time slots are allocated for uplink transmissions than for downlink transmissions) or in favor of the downlink transmissions (i.e., more time slots are allocated for downlink transmissions than for uplink transmissions). A myriad of time slot allocation schemes are possible. One simplified time slot allocation scheme uses a 'frame-based' approach. A preferred channel bandwidth analysis technique is disclosed which monitors and updates bandwidth requirement parameters associated with communication sessions, base stations and cell cluster controllers. In accordance with this technique, a communication session is preferably assigned both an 'initial' and an 'actual' set of bandwidth parameters.

Adaptive time division duplexing method and apparatus for dynamic

A method and apparatus for multiplexing time-shared base stations between a plurality of radio communication systems in a cellular communication system. Each radio communication system in the cellular system is assigned a limited unique set of frequencies for communication therein. Base stations in the cellular system are synchronized to a common time base and frequency reuse is achieved by time-sharing the frequencies via allocated time slots. Base stations activated to communicate in a first radio communication system and using the same frequencies that may interfere with each other are activated in the first system only during selected time intervals while same-frequency base stations nearby are deactivated in the first system. The deactivated base stations are then in turn activated in the first system while previously activated same-frequency base stations nearby are deactivated. Enhanced base station efficiency is achieved using the present inventive method by activating the time sharing base stations to communicate in one or more additional radio communication systems during periods when the base stations are deactivated in the first system. The radio communication systems can use differing numbers of assigned frequencies having differing time slot durations. The transmission periods used by each system may be mutually exclusive, or may overlap.

Frequency re-used and time-shared cellular communication system having

A synchronized frequency hopping method and apparatus for use in a cellular communication system where the cellular communication systems has a plurality of cells and a plurality of frequencies available to be assigned to the cells. At predetermined times, cells in the system synchronously change or hop to a new frequency. The new frequency to which a cell hops to may be a function of the present frequency the cell is assigned. In addition, synchronized frequency hopping may occur at predetermined intervals and the pattern of hopping may periodically repeat. This technique limits the period of time a non-system source of interference may impair communications in any cell since the cell hops to different frequencies periodically.

Synchronized frequency hopping

An integrated circuit chip set is provided for use in a radio communication system in which a modulated digital input signal is processed for transmission and a modulated signal received from an antenna is processed to provide an output signal, wherein the modulation of the signals is either QPSK or FSK and the signal transmission and reception is by either TDD or FDD. The chip set includes an IF integrated circuit chip for processing a digital input signal to convert the digital input signal into an analog input signal and to provide the input signal at an intermediate frequency and for processing a received signal at the intermediate frequency to down convert the frequency thereof and to provide an output signal from the down-converted received signal; and an RF integrated circuit chip for processing the input signal provided by the IF chip at the intermediate frequency to up convert the frequency thereof to a transmission frequency and for processing a received signal provided at the reception frequency to down convert the frequency thereof to the intermediate frequency. The IF chip includes switches and terminals for enabling the IF chip to be connected for processing by the IF chip of QPSK-modulated signals or to be connected for processing by the IF chip of FSK-modulated signals; and the RF chip includes terminals for enabling the RF chip to be connected for processing by the RF chip of TDD transmitted and received signals or to be connected for processing by the RF chip of FDD transmitted and received signals.

Universal radio architecture for low-tier personal communication system

A wireless data communications network having a number of users communicating from individual remote stations to a central station over a single optical-infrared channel utilizing a two-stage noncontention-based multiple-access communications protocol. During the first stage of the reservation-based polling protocol, the central station provides a synchronization signal to the remote stations to define the start of a 'reservation request period,' and allocates fixed time slots during which any remote station having a data message to transmit may request access and reserve a portion of the channel for their data messages. During the second stage or 'polled data transfer period,' the central station polls only those remote stations that have a data message to transmit and have requested access to the channel. In response to the poll, the polled remote stations transmit their data message in their previously-reserved data slots. If desired, the central station may also return an acknowledgement signal to the remote stations upon successful reception of each data message.

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Los Gatos, CA, United States of America

Sheldon L Gilbert