Motorola Corporation

John Stephen Ruppel

Michael D Kotzin

John Douglas Reed

Stephen Lee Spear

Anthony P Van Den Heuvel

Valy Lev

Ronald H Chapman

Jona Cohn

Randall R Hillock

A communication system employs a method and apparatus for exchanging communicated signals between a communication unit (e.g., 17) and a central site (205). A remote base site (65) or the central site (205) determines whether a signal must be exchanged between the communication unit (17) and the central site (205). When a signal is to be exchanged, the remote base site (65) allocates a first radio frequency communication resource (75) for use in exchanging the signal between the communication unit (17) and the remote base site (65) and a second radio frequency communication resource (74) for use in exchanging the signal between the remote base site (65) and the central site (205).

Cellular radio system using common radio backbone

A method for improved frequency assignment includes recording communications events (130), for example handoff statistics, for subscriber units handing to and away from a base station (931). The handoff statistics include the IDs of the other base stations (932-937) involved in the handoff, preferably along with the date and time of the handoff. The statistics of the handoff count are applied based on the number of occurrences within a time period (140), and are used to accept or reject the potential frequency assignments obtained from an assignment process. In one embodiment of this process, using a Q estimate, obtained from residual powers recorded on each frequency (430-435), a candidate frequency is chosen based on the lowest Q value (440). This candidate is tested against the handoff statistics, and if rejected, a frequency with the next lowest Q level is tested (450-470). This process is repeated until a frequency is assigned.

Method and apparatus for frequency assignment of a base station

The radio frequency transceiver was developed for use in a time division duplex (TDD) radiotelephone communication system. The transceiver includes a local oscillator which generates at least two local oscillator signals at different times. Each local oscillator signal has a unique frequency. During a first time period, the radio frequency transceiver receives a radio frequency signal. The first radio frequency signal is combined with one of the local oscillator signals, forming an intermediate frequency signal. During a second time period and substantially during the first time period, the transceiver generates a frequency offset signal. The frequency offset signal is combined with the second local oscillator signal, forming a second radio frequency signal. The intermediate frequency signal and the offset frequency signal are designed to have different frequencies to avoid the self-quieting problem inherent in a TDD communication system.

Frequency offset method and apparatus for use in a transceiver

An improved arrangement and method for use in a radio communication system is disclosed which makes possible mobile radio channel assignments on narrower channel spacings with a minimum amount of adjacent channel interference or splatter occurring at an included base station receiver. In a first embodiment, the mobile radios modify at least one transmission parameter, such as maximum allowable deviation, a given amount of transmitter output power, and a modulation limiting bandwidth, if a processed value of receive signal strength exceeds at least one predetermined threshold value. The processed value of receive signal strength is taken from a plurality of sampled and stored receive signal strength values in the mobile radio. By determining that the processed value of receive signal strength exceeds a predetermined threshold value, the mobile radio is able to adaptively control the amount of splatter caused at the base station, thus keeping the amount of splatter within acceptable levels. In a second embodiment, the improved arrangement and method incorporated in a mobile radio progressively adapts the transmission parameters upon determining that the processed value of receive signal strength exceeds a first, a second, and a third threshold value to effect reduced maximum allowable deviation only, reduce the maximum allowable deviation and power output only, or to reduce the maximum allowable deviation, power output, and modulation limiting bandwidth upon exceeding one, two, or all of these threshold values. Moreover, in each of these embodiments, the base station includes apparatus and a method for compensating the level and bandwidth of recovered audio by sensing the relative level of received signal strength in the base station receiver.

Adaptive splatter control

In accordance with the present invention there is provided a common antenna signal path selectively coupled to a plurality of signal energy paths, including transmitter and receiver paths. The transmitter and receiver paths are selectively coupled to the common antenna signal path by semiconductive devices capable of being variably biased from conductive to nonconductive states. In the transmit mode, the magnitude of the RF signal energy is detected and developed to adaptively maintain the disabled semiconductive device in a reverse biased or nonconducting state.

Growing community of inventors

North Richland Hills, TX, United States of America

John Stephen Ruppel