Motorola Corporation

Frederick G Atkinson

Gerald P Labedz

Barry J Menich

Duane C Rabe

Anthony Kobrinetz

Joseph J Schuler

Alton P Werronen

Gregory J Dettro

In a communications system having transmissions containing certain information-of-interest at predetermined intervals in the transmission, there is provided a method for isolating and processing that information-of-interest. The method comprises sensing the start of a transmission and isolating for processing as the information-of-interest, the information received about instant(s) predeterminally removed in time from the sensed start of transmission. Thus, the information-of-interest is isolated principally on the basis of elapsed time. The method for isolating and processing that information-of-interest is further characterized by sensing the start of a transmission from the received signal power of the transmission exceeding a predetermined threshold; AGCing the transmission and attenuating the AGC'd transmission from a maximum level to a desired level before the information-of-interest is expected to arrive; isolating for processing as the information-of-interest, the information received about instant(s) predeterminally removed in time from the sensed start of transmission, by timing the expected interval between the instant that the start of the transmission is sensed and the predetermined instant that the information-in-interest should arrive (whereby the information-of-interest is isolated principally on the basis of elapsed time); tagging the information isolated about that instant for processing; and beginning processing with information just preceeding the isolated information (whereby the reliability of the information detection is enhanced by one-to-several bits).

AGC isolation of information in TDMA systems

A method (300) and apparatus (200) provide for determining when a digital packet data signal and a voice signal are being concomitantly transmitted on a voice channel of a communication system. A sample of the transmitted signal (110) is compared (310) to a pre-transmitted sample of the digital packet data signal (108). In response to the comparison, a digital packet data transceiver hops (314-320) from the first voice channel to a different voice channel for transmitting the digital packet data signal when voice signals are present.

Method and apparatus for hopping digital packet data signals

A method and appartus for diversity reception in a communication system wherein at least a dual branch receiver is provided with a stored replica of expected reference information that is correlated with the received time-dispersed signals to obtain an estimate of the transmission channel's impulse response as seen by each branch, and determine, among other things, phase error between the branch local oscillators and the time-dispersed signals. Matched filters are constructed which then coherently align the time-dispersed signals from each branch with that branch's local oscillator, also constituting the first part of the equalization. The diversity processing stage may perform bit by bit selection on the re-aligned signals, maximal ratio combining of the re-aligned signals, or equal gain combining of the re-aligned signals, following each by a sequence estimation which uses similarly selected or combined channel distortion compensation parameters to complete the equalization process on the new signal. In digital modulated carrier systems, providing expected reference information eliminates the neeed for carrier recovery feedback for each branch while performing part of the equalization process.

Method and apparatus for diversity reception of time-dispersed signals

A method and apparatus for determining which sector antenna of a sectorized cellular radiotelephone system is receiving the strongest radio signal is disclosed. The signal strength of sector antennas is sequentially sampled, converted to digital representations, and stored according to which antenna received the signal. The digital representations are recalled from storage and the strongest signal along with an identification of the receiving antenna are determined. This determination may be used in the handoff process or in detecting when a remote unit requires a handoff.

Method and apparatus for signal strength measurement and antenna

A fixed site station for cellular systems is disclosed. A plurality of radio transceivers are removably disposed in apertures of the common equipment housing and are provided unique parameters of operation by the system controller dependent upon the aperture in which the transceiver is located and the antenna configuration of the cell being served.

Growing community of inventors

Winfield, IL, United States of America

Frederick G Atkinson