Method and apparatus for generating a simulcast response from a plurality of portable communication units
First Claim
1. A method of determining identities of respondents to a poll transmitted by a fixed communication unit in a radio communication system including a central controller, a plurality of portable communication units, and the fixed communication unit, wherein the fixed communication unit comprises a transmitter and a plurality of geographically disperse receivers, the method comprising the steps of:
- programming a plurality of bit patterns within a subset of the plurality of portable communication unit for identifying individual portable communication units of said subset, each bit pattern corresponding uniquely to a portable communication unit and chosen such that when a group of at least two of the portable communication units are received simultaneously by a receiver of the plurality of receivers, thereby producing an interference bit pattern in the receiver, the interference bit pattern provides a non-zero probability of correctly identifying at least a portion of said group, and a substantially zero probability of erroneously identifying a portable communication unit not in said group;
transmitting thereafter from said subset a plurality of simultaneous, co-channel responses to the poll, a response comprising one of said plurality of bit patterns transmitted without modification, exactly as programmed; and
determining therefrom identities of received portable communication units of said subset by the interference bit patterns received by the plurality of receivers.
1 Assignment
0 Petitions
Accused Products
Abstract
A method and apparatus identify (822) respondents to a poll transmitted (806) in a radio communication system (100) comprising a transmitter (104) and a plurality of receivers (103, 105). A subset of a plurality of portable communication units (PCUs) (108) are each programmed (804, 806) with a bit pattern (510, 512, 514) corresponding uniquely to each PCU (108) and chosen such that when a group of at least two PCUs (108) are received simultaneously, the resultant received interference bit pattern provides a non-zero probability of correctly identifying at least a portion of the group, and a substantially zero probability of erroneously identifying a PCU (108) not in the group. The method further comprises the steps of transmitting (808) thereafter from the subset of PCUs (108) simultaneous, co-channel responses to the poll, each response comprising one of the programmed bit patterns (510, 512, 514), and determining (822) therefrom identities of received PCUs (108) by the interference bit patterns received at the plurality of receivers (103, 105).
60 Citations
21 Claims
-
1. A method of determining identities of respondents to a poll transmitted by a fixed communication unit in a radio communication system including a central controller, a plurality of portable communication units, and the fixed communication unit, wherein the fixed communication unit comprises a transmitter and a plurality of geographically disperse receivers, the method comprising the steps of:
-
programming a plurality of bit patterns within a subset of the plurality of portable communication unit for identifying individual portable communication units of said subset, each bit pattern corresponding uniquely to a portable communication unit and chosen such that when a group of at least two of the portable communication units are received simultaneously by a receiver of the plurality of receivers, thereby producing an interference bit pattern in the receiver, the interference bit pattern provides a non-zero probability of correctly identifying at least a portion of said group, and a substantially zero probability of erroneously identifying a portable communication unit not in said group; transmitting thereafter from said subset a plurality of simultaneous, co-channel responses to the poll, a response comprising one of said plurality of bit patterns transmitted without modification, exactly as programmed; and determining therefrom identities of received portable communication units of said subset by the interference bit patterns received by the plurality of receivers. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. Apparatus in a radio communication system for transmitting a poll and determining identities of respondents to said poll, said apparatus comprising:
-
controller means for controlling said radio communication system; fixed communication means coupled to said controller means for transmitting said poll and further for receiving a response to said poll, wherein said fixed communication means comprises a transmitter and a plurality of receivers positioned in geographically disperse locations; a plurality of portable communication units coupled to said fixed communication means for receiving said poll and generating a response; and programmer means for coupling to ones of said plurality of portable communication units for programming therein a plurality of bit patterns for identifying each individual portable communication unit within a subset of said plurality of portable communication units, each bit pattern corresponding uniquely to a portable communication unit and chosen such that when a group of at least two of said portable communication units are received simultaneously by a receiver of said plurality of receivers, thereby producing an interference bit pattern in said receiver, said interference bit pattern provides a non-zero probability of correctly identifying at least a portion of said group, and a substantially zero probability of erroneously identifying a portable communication unit not in said group, wherein said plurality of portable communication units each comprise response transmitter means for transmitting from said subset, after programming by said programmer means, a plurality of substantially simultaneous, co-channel responses to said poll, a response comprising one of said plurality of bit patterns transmitted without modification, exactly as programmed by said programmer means, and wherein said controller means comprises processor means coupled to said response transmitter means for determining identities of received portable communication units of said subset by interference bit patterns received by said plurality of receivers. - View Dependent Claims (9, 10, 11, 12, 13, 14)
-
-
15. Apparatus in a radio communication system for transmitting a poll and determining identities of respondents to said poll, said apparatus comprising:
-
a central controller for controlling said radio communication system; a fixed communication unit coupled to said central controller for transmitting said poll and further for receiving a response to said poll, wherein said fixed communication unit comprises a transmitter and a plurality of receivers positioned in geographically disperse locations; a plurality of portable communication units coupled to said fixed communication unit for receiving said poll and generating a response; and a programmer for coupling to ones of said plurality of portable communication units for programming therein a plurality of bit patterns for identifying each individual portable communication unit within a subset of said plurality of portable communication units, each bit pattern corresponding uniquely to a portable communication unit and chosen such that when a group of at least two of said portable communication units are received simultaneously by a receiver of said plurality of receivers, thereby producing an interference bit pattern in said receiver, said interference bit pattern provides a non-zero probability of correctly identifying at least a portion of said group, and a substantially zero probability of erroneously identifying a portable communication unit not in said group, wherein said plurality of portable communication units each comprise a response transmitter for transmitting from said subset, after programming by said programmer, a plurality of substantially simultaneous, co-channel responses to said poll, a response comprising one of said plurality of bit patterns transmitted without modification, exactly as programmed by said programmer, and wherein said central controller comprises a processor coupled to said response transmitter for determining identities of received portable communication units of said subset by interference bit patterns received by said plurality of receivers. - View Dependent Claims (16, 17, 18, 19, 20, 21)
-
Specification