Motorola Corporation

Other

Dennis R Schaeffer

Jeffrey D Bonta

Michael D Kotzin

Barry J Menich

Mark T Ahlenius

Daniel Richard Tayloe

Stephen Lee Spear

Gerald P Labedz

Valy Lev

Kenneth A Felix

Daniel Francis Tell

Dennis J Thompson

John S Csapo

Victor Graziano

Edward J Hofstra

A method and apparatus for implementing spatial diversity utilizing coaxial interconnections between a plurality of receivers, transmitters and radiating elements in a communication system is disclosed. The long coaxial line used for feeding associated receive antennas is used for creating delay of a signal for implementing downlink diversity. Similarly, the long coaxial lines used for feeding associated transmit antennas are used for creating delay of a signal for implementing uplink diversity. The method and apparatus, in particular, further includes utilization of at least one of the radiating elements for receiving a signal and transmitting a delayed version of a signal to be transmitted.

Method and apparatus for producing delay of a carrier signal for

A wireless communication system (200, 300, 400, 500) mitigates the effects of excess timing delay caused by varying lengths of communication paths. In one general implementation, a transition communication path (206, 323, 329) is used to transfer a time-advanced version of a timing reference signal so that the cumulative time delay at a transition cell (209, 325, 331) is reduced. In another general implementation, the timing reference signal is time-advanced in all communication paths (403-411), and selected communication paths (403-407) include a time delay means (423-427, 503-507) such that the cumulative time delay at an area (421) near a target coverage area (130) is reduced. By reducing the cumulative time delay at the area (421) near the target coverage area (130), a handoff of a communication of a mobile station (128) into the target coverage area (130) can be performed.

Apparatus and method for mitigating excess time delay in a wireless

A base site (100) employs a method and apparatus for selecting two of a plurality of antennas (101-106) from which to receive a communication signal. A first signal quality metric is measured for a communication signal received from a first antenna (102) and a second signal quality metric is measured for the communication signal received from a second antenna (103). When the first signal quality metric differs from the second signal quality metric by a threshold, a signal receiver (113) is coupled to a third antenna (e.g., 101) and a third signal quality metric is measured for the communication signal received from the third antenna (101). Based on the three signal quality metrics, a primary antenna and a secondary antenna are selected from which to receive the communication signal.

Method and apparatus for selecting two antennas from which to receive a

A method is provided of topographically displaying selected information of a plurality of cells within a cellular communication system through a display device. The method includes the steps of accessing the selected information from an information database and correlating the selected information to respective cells of the plurality of cells. The method further includes the step of creating a topographical display of the plurality of cells of the cellular system through the use of representative polygons, with each polygon representing a service coverage area of a cell of the plurality of cells and displaying the selected information as visually variable values within the representative polygons of the topographical display.

Method of topographically displaying selected information in a cellular

A method of allocating communication resources in a communication system includes retrieving (404) from the communication system a communication system resource allocation. An allocation parameter is set to an initial value (406) and communication resources are randomly selected from cells (414). A candidate communication resource is either swapped or mutated for the selected communication resource (416) and the system performance is evaluated with the candidate communication resource (422). If system performance is improved the candidate resource is retained as part of the allocation (426, 432), or if system performance is degraded, the candidate resource is retained with a probability (428, 432). The steps repeat while the allocation parameter is valid (408), and upon completion a new communication resource allocation is downloaded to the communication system (410).

Communication system resource allocation method

In a cellular radiotelephone network, there is provided a mechanism for dynamic frequency reuse. It comprises: allocating according to one reuse pattern during one time interval at least one of a plurality of hopped carriers and allocating according to another reuse pattern during another, substantially non-overlapping time interval that hopped carrier, all in substantially non-interfering time synchronism with any proximal reuse of that carrier. The attendant advantage is the realization of a dynamically allocatable frequency reuse, using shared carriers and frequency hopping to provide the desired C/I performance.

Hopped-carrier dynamic frequency reuse

A communication system having a site employing a plurality of communication channels. Each channel is assigned a desired received signal strength threshold. A channel is assigned to a subscriber unit based upon the strength of the signal received at the site and the power control range of the subscriber unit. The selection of a channel may be performed either by the site or the subscriber unit. In an FDMA environment, each separate frequency division channel may be assigned different received signal strength thresholds. In a non-overlapping time interval (TDMA) environment, each separate time division channel may be assigned different received signal strength thresholds. In another embodiment, a combination of FDMA and TDMA environments can be used.

Multiple user spread-spectrum communication system

A cellular radiotelephone communications system comprising a system of cells that are made up of an array of diretional sector antennas. These antennas are centrally located in the cell and radiates into a 60.degree. area of the cell. Each antenna in a cell has a group of frequencies assigned to it that is different than the group of frequencies assigned to the other antennas within that cell. These frequency groups are repeated either 2 or 8 times respectively in a 4 or 16 cell repeat pattern, effectively forming a two cell reuse pattern. The preferred embodiment of this invention is asymmetrically positioning the repeating frequency groups in an alternating fashion so that one row faces in the opposite direction of another row. The asymmetrical positioning of cells is possible only by departing from the prior art, cellular positioning rules. The positioning rules used in this invention create a 4 or 16 cell repeat pattern by locating co-channel cells closer in one direction than another.

Cellular radiotelephone communications system

A signal routing system for use in cellular RF communications systems wherein a signal can be routed to different antennas, effectively switching transmitters between antennas. The switching is accomplished by placing a frequency responsive device between a transmitter and each antenna. The transmitter is then coupled to an antenna through the frequency responsive device that has a resonant frequency equal to the transmitter's frequency. If the transmitter changes frequency, it will be switched to the appropriate antenna through the corresponding frequency responsive device. This system permits a sector of a cell to increase the number of frequencies in that sector to handle increased mobile traffic loads.

Signal routing system

An improved TDMA radiotelephone cellular communication system employs an improved cell site scan monitoring technique. The technique includes monitoring radiotelephone calls, and tracking and recording their signal qualities. The records are used to maintain and determine which frequencies and which time partitions at the base site equipment are being utilized for radiotelephone communication. When a new call assignment is required at a cell site, it is assigned to a time partition of a base site equipment frequency in a frequency prioritized manner such that radiotelephone calls are concentrated within each frequency so as to reduce the number of frequencies carrying radiotelephone calls.

Reuse groups for scan monitoring in digital cellular systems

A cellular radiotelephone system (101) includes a control terminal (420) coupled by in trunks and out trunks to the telephone central office (110) and by data and voice lines to base sites (411-416) in corresponding cells (401-406) for providing telephone coverage to mobiles located throughout a geographical area. In order accommodate additional voice channels in each cell (401-405), base sites (441-446) are colocated with corresponding existing base sites (401-405). Paging/access channels are assigned to existing base sites (411-416) for paging mobiles for all outgoing originations and processing all incoming mobile originations and page responses. Access-only channels are assigned to colocated base sites (441-446) for processing mobile originations and page responses transferred thereto by a directed retry message from corresponding existing base sites (401-405). The additional voice channels assigned to colocated base sites (441-446) may be voice channels in new radio frequency bands allocated to cellular radiotelephone systems. If both existing and additional voice channels are assigned to existing base sites (411-416) and/or colocated base sites (441-446), new voice channels are assigned to requesting mobiles before assigning existing voice channels, provided that the requesting mobile operates on both existing and new voice channels.

Cellular radiotelephone system having colocated base sites

A cellular radiotelephone system providing service to remote units having a voice operated transmitter (VOX) is disclosed. If the regularly scheduled periodic signal quality measurements made by fixed site equipment indicate that the remote unit signal has not been received for a predetermined number of measurements, an audit request is transmitted to the remote unit. The remote unit responsively keys its transmitter for a predetermined period of time. A first special scan is programmed into the regular process such that the fixed site equipment may continue with its regular process until the signal quality measurement must be made. A second measurement is made following the first and if the two signal quality measurements made while the VOX remote unit is known to be transmitting agree, system reconfiguration for the service of this remote unit may be implemented by the cellular system.

VOX remote unit control in a cellular system

A method and apparatus for utilizing voice channel transceivers as temporary scanning receivers in a handoff event for a cellular radiotelephone system is disclosed. Voice channel transceiver identifications are stored in link lists according to priority, sectorization, and last use. When a signal strength measurement is required, those cell sectors having available voice channel transceivers are identified and a table providing optimum transceiver selection is utilized to select those voice channel transceivers which will make the signal strength measurement.

Scanning receiver allocation method and apparatus for cellular

A data message transmission system for a cellular radiotelephone system is disclosed. Data to be transmitted is converted into a format compatible with radio transmission prior to transmission. The data is reconverted to its original format following reception. Handoff is accomplished by halting the data transmission prior to handoff and resuming data transmission after handoff. Call supervision occurs via busy-idle bit coding.

Growing community of inventors

Buffalo Grove, IL, United States of America

Dennis R Schaeffer