Time division multiplexed selective call system
First Claim
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1. In a selective call system, a method for generating and transmitting a signal comprising a plurality of phases at a baud rate comprising the steps of:
- receiving a plurality of selective call messages, each of said plurality of selective call messages having one of a plurality of selective call addresses corresponding thereto;
time division multiplexing said plurality of selective call messages into said plurality of phases to form said signal, which of said plurality of phases for placing one of said plurality of selective call messages determined in response to said baud rate and one of said plurality of selective call addresses corresponding to said one of said plurality of selective call messages, wherein said step of time division multiplexing comprises the steps of;
storing each of said plurality of selective call messages as a plurality of message bits in one of a predetermined number of phase queues, the one of said predetermined number of phase queues determined by said selective call addresses and the predetermined number determined by said baud rate; and
generating said signal comprising a bit stream, by serially inserting each of said plurality of message bits from each of said predetermined number of phase queues in a sequence starting with a first of said message bits stored in a first of said predetermined number of phase queues and thereafter sequentially inserting message bits in a wraparound manner such that after inserting a first of said message bits stored in a last of said predetermined number of phase queues, next inserting a second of said message bits stored in said first of said predetermined number of phase queues; and
transmitting said signal.
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Abstract
A signalling protocol comprising a plurality of interleaved phases is transmitted at various baud rates, the various baud rates being multiples of a base baud rate. The signalling protocol allows a selective call receiver to decode at an operating baud rate equivalent to the base baud rate irrespective of the transmission baud rate by decoding only a portion of the transmitted signal, the portion decoded determined by the baud rate and the address of the selective call receiver.
47 Citations
22 Claims
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1. In a selective call system, a method for generating and transmitting a signal comprising a plurality of phases at a baud rate comprising the steps of:
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receiving a plurality of selective call messages, each of said plurality of selective call messages having one of a plurality of selective call addresses corresponding thereto; time division multiplexing said plurality of selective call messages into said plurality of phases to form said signal, which of said plurality of phases for placing one of said plurality of selective call messages determined in response to said baud rate and one of said plurality of selective call addresses corresponding to said one of said plurality of selective call messages, wherein said step of time division multiplexing comprises the steps of; storing each of said plurality of selective call messages as a plurality of message bits in one of a predetermined number of phase queues, the one of said predetermined number of phase queues determined by said selective call addresses and the predetermined number determined by said baud rate; and generating said signal comprising a bit stream, by serially inserting each of said plurality of message bits from each of said predetermined number of phase queues in a sequence starting with a first of said message bits stored in a first of said predetermined number of phase queues and thereafter sequentially inserting message bits in a wraparound manner such that after inserting a first of said message bits stored in a last of said predetermined number of phase queues, next inserting a second of said message bits stored in said first of said predetermined number of phase queues; and transmitting said signal. - View Dependent Claims (2)
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3. A selective call system for transmitting selective call messages to a plurality of selective call receivers at one of a plurality of predetermined baud rates, each of said selective call messages having an address, the selective call system comprising:
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a selective call terminal comprising; multiplexing means for generating a signal having a plurality of phases by time division multiplexing each of said selective call messages into at least one of said plurality of phases in response to said address of said each of said selective call messages and said one of said plurality of predetermined baud rates, wherein said multiplexing means comprises; a number of phase queues, each of said number of phase queues for storing each of said plurality of phases; queue determining means for determining in which of said number of phase queues to store one of said plurality of selective call messages in response to said address of said one of said plurality of messages; and bit selection means for generating said signal by time division multiplexing said plurality of phases by selecting bits of said plurality of selective call messages serially from each of said number of phase queues in a sequence starting with a first of said bits stored in a first of said number of phase queues and thereafter sequentially selecting one of said bits in a wraparound manner such that after selecting a first of said bits stored in a last of said number of phase queues, next inserting a second of said bits stored in said first of said number of phase queues; and transmitting means for transmitting said signal at said one of said plurality of predetermined baud rates; and a plurality of selective call receivers having selective call addresses, each of said plurality of selective call receivers comprising; receiving means for receiving and demodulating said signal; storage means for storing predetermined information; and decoding means for decoding at least one of said plurality of phases of said signal, said at least one of said plurality of phases determined by said predetermined information. - View Dependent Claims (4, 5, 6, 7, 8)
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9. A selective call receiver comprising:
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receiving means for receiving and demodulating a first signal received at a first data baud rate to recover first bit stream information having said first data baud rate, said first bit stream information comprising a first plurality of bits; decoding means for decoding said first bit stream information at a second data baud rate to derive a selective call message, wherein said second data baud rate is different from said first data baud rate; control means coupled to said receiving means and said decoding means for providing only a first bit of every N bits of said first plurality of bits recovered by said receiving means to said decoding means such that said decoding means decodes said first bit of every N bits of said first plurality of bits, wherein N is an integer and is equivalent to said first data baud rate divided by said second data baud rate. - View Dependent Claims (10, 11, 12)
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13. A selective call receiver comprising:
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receiving means for receiving and demodulating a signal having a first portion received at a first data baud rate to recover first bit stream information having said first data baud rate and for receiving and demodulating a second portion received at a second data baud rate different from said first data baud rate to recover second bit stream information having said second data baud rate; decoding means for decoding said first and second bit stream information at said first data baud rate; and control means coupled to said receiving means and said decoding means for providing every bit of said first bit stream information recovered by said receiving means to said decoding means such that said decoding means decodes said every bit at said first data baud rate, and for providing only a first bit of every N bits of said second bit stream information recovered by said receiving means to said decoding means such that said decoding means decodes said first bit of every N bits of said second bit stream information at said first data baud rate, where N is integer and is equivalent to said second data baud rate divided by said first data baud rate. - View Dependent Claims (14)
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15. In a selective call system, a method for generating a signal for transmission at a baud rate comprising the steps of:
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receiving a plurality of selective call messages, each of said plurality of selective call messages having one of a plurality of selective call addresses corresponding thereto; determining a message traffic density in response to the number of said plurality of selective call messages received within a predetermined time duration; time division multiplexing said plurality of selective call messages into a number of phases to form said signal for transmission at said baud rate, said number of phases and said baud rate determined by said message traffic density and which of said number of phases for placing one of said plurality of selective call messages determined by said baud rate and one of said plurality of selective call addresses corresponding to said one of said plurality of selective call messages, wherein said step of time division multiplexing comprises the steps of; storing each of said plurality of selective call messages as a plurality of message bits in one of a number of phase queues, the number of phase queues corresponding to said number of phases and said one of said number of phase queues determined by said one of said plurality of selective call addresses corresponding to the one of said plurality of selective call messages; and generating said signal comprising a bit stream, by serially inserting each of said plurality of message bits from each of said number of phase queues in a sequence starting with a first of said message bits stored in a first of said number of phase queues and thereafter sequentially inserting message bits in a wraparound manner such that after inserting a first of said message bits stored in a last of said number of phase queues, next inserting a second of said message bits stored in said first of said number of phase queues; and transmitting said signal. - View Dependent Claims (16)
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17. A method in a communication system for transmitting a plurality of selective call messages at a first baud rate from a terminal to at least one receiver having at least one address assigned thereto, the method comprising the steps of:
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at said terminal receiving a plurality of messages, each of said messages having one of a plurality of selective call addresses corresponding thereto; combining each of said messages with said one of said plurality of selective call addresses corresponding thereto to form one of said plurality of selective call messages, each of said plurality of selective call messages having a plurality of message bits; time division multiplexing said plurality of selective call messages into a number of phases to form said number of phases each comprising bits by assigning the plurality of message bits of each of said plurality of selective call messages to one of said number of phases, said number of phases determined by said first baud rate and said one of said plurality of phases for assigning each of said plurality of selective call messages determined by said first baud rate and said one of said plurality of selective call addresses corresponding to said one of said plurality of selective call messages; encoding said plurality of selective call messages into a signal by serially inserting one of said bits from each of said number of phases in a manner starting with a first of said bits stored in a first of said number of phases and thereafter sequentially inserting ones of said bits in a wraparound manner such that after inserting a first of said bits stored in a last of said number of phases, next inserting a second of said bits stored in said first of said number of phases; and transmitting said signal at said first baud rate; at each of said at least one receiver receiving and demodulating said signal; decoding a first portion of each of said plurality of selective call messages of said signal in one of said number of phases at a second baud rate to determine whether said one of said plurality of selective call addresses corresponding thereto is the address assigned to said one of said at least one receiver, said first baud rate being an integer multiple of said second baud rate and said one of said number of phases determined by said first baud rate and the address assigned to said one of said at least one receiver; and decoding a remaining portion of one of said plurality of selective call messages in said one of said number of phases at said second baud rate if said step of decoding a first portion determines that said one of said plurality of selective call addresses corresponding to said one of said plurality of selective call messages is the address assigned to said one of said at least one receiver.
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18. A selective call system for transmitting selective call messages to a plurality of selective call receivers at one of a plurality of predetermined baud rates, each of said selective call messages having an address, the selective call system comprising:
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a selective call terminal comprising; input means for receiving message information; interleaving means for interleaving said message information to form said selective call messages; multiplexing means for generating a signal having a plurality of phases by time division multiplexing each of said selective call messages into at least one of said plurality of phases in response to said address of said each of said selective call messages and said one of said plurality of predetermined baud rates; and transmitting means for transmitting said signal at said one of said plurality of predetermined baud rates; and a plurality of selective call receivers having selective call addresses, each of said plurality of selective call receivers comprising; receiving means for receiving and demodulating said signal; storage means for storing predetermined information; and decoding means for decoding at least one of said plurality of phases of said signal, said at least one one of said plurality of phases determined by said predetermined information, said decoding means comprising; phase extracting means for extracting said at least one of said plurality of phases from said signal; deinterleaving means for deinterleaving said at least one of said plurality of phases; and processing means for decoding said selective call messages to derive said message information.
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19. A selective call receiver for receiving a signal having a plurality of baud rates, each of said plurality of baud rates being an integer multiple of a predetermined one of said plurality of baud rates, the signal comprising synchronization information having a first portion and a second portion, the selective call receiver comprising:
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receiving means for receiving and demodulating the signal; synchronizing means for processing the first portion of the synchronization information of the demodulated signal at the predetermined one of said plurality of baud rates to acquire coarse bit and frame synchronization to the signal and for processing the second portion of the synchronization information at one of said plurality of baud rates other than the predetermined one of said plurality of baud rates to acquire fine bit and frame synchronization to the signal; and decoding means for decoding the signal in accordance with said one of said plurality of baud rates other than the predetermined one of said plurality of baud rates. - View Dependent Claims (20, 21, 22)
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Specification