Radio communication system and transmitter and receiver equipment therefor

Claim 1

A system located at a first station to provide two-way radio communication with a second station wherein said second station is equipped to receive a radio signal and to transmit an interrogation radio signal and also an information-bearing radio signal having an information signal component and key signal component, said system comprising first means providing for the reception of said information-bearing signal but not said interrogation signal, second means for retrieving said information and key signal components from the information-bearing signal received by said first means, an electrically programmable read/write memory, third means for storing a preselected code, fourth means connected to said memory for enabling information to be written into and read out of said memory, said fourth means including a circuit for comparing the retrieved key signal component with said pre-selected code and for writing the information contained in said information signal component into said memory only if the retrieved key signal component corresponds to said code, fifth means for receiving said interrogation signal, but not said information-bearing signal and sixth means rendered effective upon the reception of said interrogation signal for transmitting the information stored in said memory in the form of a signal that is receivable by said second station.

Claim 2

A system located at a first station to provide two-way radio communication with a second station wherein said second station is equipped to receive a radio signal and to transmit an interrogation radio signal and also an information-bearing radio signal having an information signal component and key signal component, said system comprising first means providing for the reception of said information-bearing signal but not said interrogation signal, second means for retrieving said information and key signal components from the information-bearing signal received by said first means, an electrically programmable read/write memory, third means for storing a preselected code, fourth means connected to said memory for enabling information to be written into and read out of said memory, said fourth means including a circuit for comparing the retrieved key signal component with said pre-selected code and for writing the information contained in said information signal component into said memory only if the retrieved key signal component corresponds to said code, fifth means for receiving said interrogation signal, but not said information-bearing signal and sixth means rendered effective upon the reception of said interrogation signal for transmitting the information stored in said memory in the form of a signal that is receivable by said second station.

Claim 5

A system located at a first station to provide two-way radio communication with a second station wherein said second station is equipped to receive a radio signal and to transmit an interrogation radio signal and also an information-bearing radio signal having an information signal component and key signal component, said system comprising first means providing for the reception of said information-bearing and interrogation signals, second means for retrieving said information and key signal components from said information-bearing signal, an electrically programmable read/write memory, third means for storing a preselected code, fourth means connected to said memory for enabling information to be written into and read out of said memory, said fourth means including a circuit for comparing the retrieved key signal component with said pre-selected code and for writing the information contained in said information signal component into said memory only if the retrieved key signal component corresponds to said code, and fifth means rendered effective upon the reception of said interrogation signal for transmitting the information stored in said memory in the form of a signal that is receivable by said first station, said interrogating and information-bearing signals being dissimilarly polarized, and said first means including first antenna means oriented to receive said information-bearing signal but not said interrogation signal, and second antenna means oriented to receive said interrogation signal but not said information-bearing signal.

Claim 6

A system located at a first station to provide two-way radio communication with a second station wherein said second station is equipped to receive a radio signal and to transmit an interrogation radio signal and also an information-bearing radio signal having an information signal component and key signal component, said system comprising first means providing for the reception of said information-bearing and interrogation signals, second means for retrieving said information and key signal components from said information-bearing signal, an electrically programmable read/write memory, third means for storing a preselected code, fourth means connected to said memory for enabling information to be written into and read out of said memory, said fourth means including a circuit for comparing the retrieved key signal component with said pre-selected code and for writing the information contained in said information signal component into said memory only if the retrieved key signal component corresponds to said code, and fifth means rendered effective upon the reception of said interrogation signal for transmitting the information stored in said memory in the form of a signal that is receivable by said first station, said interrogating and information-bearing signals being dissimilarly polarized, and said first means including first antenna means oriented to receive said information-bearing signal but not said interrogation signal, and second antenna means oriented to receive said interrogation signal but not said information-bearing signal.

Claim 7

A system located at a first station to provide two-way radio communication with a second station wherein said second station is equipped to receive a radio signal and to transmit an interrogation radio signal and also an information-bearing radio signal having an information signal component and key signal component, said system comprising first means providing for the reception of said information-bearing signal but not said interrogation signal, second means for retrieving said information and key signal components from the information-bearing signal received by said first means, an electrically programmable read/write memory, third means for storing a pre-selected code, fourth means connected to said memory for enabling information to be written into and read out of said memory, said fourth means including a circuit for comparing the retrieved key signal component with said preselected code and for writing the information contained in said information signal component into said memory only if the retrieved key signal component corresponds to said code, said circuit of said fourth means comprising a comparator having an output connected to a read/write terminal of said memory, there being further means for applying said key signal component to said comparator, and said comparator providing for the comparison of said key signal component with said code and for the application of said write signal to the read/write terminal of said memory only when said key signal component corresponds to said code, said memory being conditioned by said write signal to store the information contained in said information signal component, and said comparator being effective to apply a read signal to said read/write terminal to place said memory in its read mode upon sensing the absence of a signal corresponding to said code, fifth means for receiving said interrogation signal, but not said information-bearing signal, and sixth means rendered effective upon the reception of said interrogation signal for transmitting the information stored in said memory in the form of a signal that is receivable by said second station when said memory is in its read mode.

Claim 8

A system located at a first station to provide two-way radio communication with a second station wherein said second station is equipped to receive a radio signal and to transmit an interrogation radio signal and also an information-bearing radio signal having an information signal component and key signal component, said system comprising first means providing for the reception of said information-bearing signal but not said interrogation signal, second means for retrieving said information and key signal components from the information-bearing signal received by said first means, an electrically programmable read/write memory, third means for storing a pre-selected code, fourth means connected to said memory for enabling information to be written into and read out of said memory, said fourth means including a circuit for comparing the retrieved key signal component with said preselected code and for writing the information contained in said information signal component into said memory only if the retrieved key signal component corresponds to said code, said circuit of said fourth means comprising a comparator having an output connected to a read/write terminal of said memory, there being further means for applying said key signal component to said comparator, and said comparator providing for the comparison of said key signal component with said code and for the application of said write signal to the read/write terminal of said memory only when said key signal component corresponds to said code, said memory being conditioned by said write signal to store the information contained in said information signal component, and said comparator being effective to apply a read signal to said read/write terminal to place said memory in its read mode upon sensing the absence of a signal corresponding to said code, fifth means for receiving said interrogation signal, but not said information-bearing signal, and sixth means rendered effective upon the reception of said interrogation signal for transmitting the information stored in said memory in the form of a signal that is receivable by said second station when said memory is in its read mode.

Claim 9

A system located at a first station to provide two-way radio communication with a second station wherein said second station is equipped to receive a radio signal and to transmit an interrogation radio signal and also an information-bearing radio signal having an information signal component and key signal component, said system comprising antenna means for emitting signals and also for receiving said information-bearing and interrogation signals, first means for retrieving said information and key signal components from the received information-bearing signal, an electrically programmable read/write memory, second means for storing a pre-selected code, third means connected to said memory for enabling information to be written into and read out of said said memory, said third means including a circuit for comparing the retrieved key signal component with said pre-selected code and for writing the information contained in said information signal component into said memory only if the retrieved key signal component corresponds to said code, and fourth means rendered effective upon reception of said interrogation signal for supplying the information stored in said memory in the form of a modulated signal that is receivable by said second station, said antenna means having an antenna electrically connected to said fourth means for emitting said modulated signal, and said fourth means including a pulse generator, a counter and a modulator, said memory having a data output connected to said generator for feeding information stored in the memory to said generator in the form of a digital signal when said memory is in its read mode, said generator being responsive to said digital signal for producing a further signal which is coded to contain the information read out of said memory and which is formed with serially occurring pulses, said counter being connected to said pulse generator for counting the pulses supplied by said generator and having an output connected to said memory for addressing different storage locations in said memory in accordance with the pulse count in the counter, and said modulator being connected to said generator to modulate a signal with said further signal to develop said modulated signal.

Claim 10

A system located at a first station to provide two-way radio communication with a second station wherein said second station is equipped to receive a radio signal and to transmit an interrogation radio signal and also an information-bearing radio signal having an information signal component and key signal component, said system comprising antenna means for emitting signals and also for receiving said information-bearing and interrogation signals, first means for retrieving said information and key signal components from the received information-bearing signal, an electrically programmable read/write memory, second means for storing a pre-selected code, third means connected to said memory for enabling information to be written into and read out of said said memory, said third means including a circuit for comparing the retrieved key signal component with said pre-selected code and for writing the information contained in said information signal component into said memory only if the retrieved key signal component corresponds to said code, and fourth means rendered effective upon reception of said interrogation signal for supplying the information stored in said memory in the form of a modulated signal that is receivable by said second station, said antenna means having an antenna electrically connected to said fourth means for emitting said modulated signal, and said fourth means including a pulse generator, a counter and a modulator, said memory having a data output connected to said generator for feeding information stored in the memory to said generator in the form of a digital signal when said memory is in its read mode, said generator being responsive to said digital signal for producing a further signal which is coded to contain the information read out of said memory and which is formed with serially occurring pulses, said counter being connected to said pulse generator for counting the pulses supplied by said generator and having an output connected to said memory for addressing different storage locations in said memory in accordance with the pulse count in the counter, and said modulator being connected to said generator to modulate a signal with said further signal to develop said modulated signal.

Claim 11

A system located at a first station to provide two-way radio communication with a second station wherein said second station is equipped to receive a radio signal and to transmit an interrogation radio signal and also an information-bearing radio signal having an information signal component and key signal component, said system comprising antenna means for emitting signals and also for receiving said information-bearing and interrogation signals, first means for retrieving said information and key signal components from the received information-bearing signal, an electrically programmable read/write memory, second means for storing a pre-selected code, third means connected to said memory for enabling information to be written into and read out of said memory, said third means including a circuit for comparing the retrieved key signal component with said pre-selected code and for writing the information contained in said information signal component into said memory only if the retrieved key signal component corresponds to said code, and fourth means rendered effective upon reception of said interrogation signal for supplying the information stored in said memory in the form of a modulated signal that is receivable by said second station, said antenna means having an antenna electrically connected to said fourth means for emitting said modulated signal, and said fourth means including a pulse generator, a counter and a modulator, said memory having a data output connected to said generator for feeding information stored in the memory to said generator in the form of a digital signal when said memory is in its read mode, said generator being responsive to said digital signal for producing a further signal which is coded to contain the information read out of said memory and which is formed with serially occurring pulses, said counter being connected to said pulse generator for counting the pulses supplied by said generator and having an output connected to said memory for addressing different storage locations in said memory in accordance with the pulse count in the counter, and said modulator being connected to said generator to modulate said interrogating signal with said further signal to develop said modulated signal.

Claim 12

A system located at a first station to provide two-way radio communication with a second station wherein said second station is equipped to receive a radio signal and to transmit an interrogation radio signal and also an information-bearing radio signal having an information signal component and key signal component, said system comprising antenna means for emitting signals and also for receiving said information-bearing and interrogation signals, first means for retrieving said information and key signal components from the received information-bearing signal, an electrically programmable read/write memory, second means for storing a pre-selected code, third means connected to said memory for enabling information to be written into and read out of said memory, said third means including a circuit for comparing the retrieved key signal component with said pre-selected code and for writing the information contained in said information signal component into said memory only if the retrieved key signal component corresponds to said code, and fourth means rendered effective upon reception of said interrogation signal for supplying the information stored in said memory in the form of a modulated signal that is receivable by said second station, said antenna means having an antenna electrically connected to said fourth means for emitting said modulated signal, and said fourth means including a pulse generator, a counter and a modulator, said memory having a data output connected to said generator for feeding information stored in the memory to said generator in the form of a digital signal when said memory is in its read mode, said generator being responsive to said digital signal for producing a further signal which is coded to contain the information read out of said memory and which is formed with serially occurring pulses, said counter being connected to said pulse generator for counting the pulses supplied by said generator and having an output connected to said memory for addressing different storage locations in said memory in accordance with the pulse count in the counter, and said modulator being connected to said generator to modulate said interrogating signal with said further signal to develop said modulated signal.

Claim 13

A system located at a first station to provide two-way radio communication with a second station wherein said second station is equipped to receive a radio signal and to transmit an interrogation radio signal and also an information-bearing radio signal having an information signal component and key signal component, said system comprising antenna means for emitting signals and also for receiving said information-bearing and interrogation signals, first means for retrieving said information and key signal components from the received information-bearing signal, an electrically programmable read/write memory, second means for storing a pre-selected code, third means connected to said memory for enabling information to be written into and read out of said memory, said third means including a circuit for comparing the retrieved key signal component with said pre-selected code and for writing the information contained in said information signal component into said memory only if the retrieved key signal component corresponds to said code, and fourth means rendered effective upon reception of said interrogation signal for supplying the information stored in said memory in the form of a modulated signal that is receivable by said second station, said antenna means having an antenna electrically connected to said fourth means for emitting said modulated signal, and said fourth means including a pulse generator, a counter and a modulator, said memory having a data output connected to said generator for feeding information stored in the memory to said generator in the form of a digital signal when said memory is in its read mode, said generator being responsive to said digital signal for producing a further signal which is coded to contain the information read out of said memory and which is formed with serially occurring pulses, said counter being connected to said pulse generator for counting the pulses supplied by said generator and having an output connected to said memory for addressing different storage locations in said memory in accordance with the pulse count in the counter, and said modulator being connected to said generator to phase modulate said interrogating signal with said further signal to develop said modulated signal.

Claim 14

A system located at a first station to provide two-way radio communication with a second station wherein said second station is equipped to receive a radio signal and to transmit an interrogation radio signal and also an information-bearing radio signal having an information signal component and key signal component, said system comprising antenna means for emitting signals and also for receiving said information-bearing and interrogation signals, first means for retrieving said information and key signal components from the received information-bearing signal, an electrically programmable read/write memory, second means for storing a pre-selected code, third means connected to said memory for enabling information to be written into and read out of said memory, said third means including a circuit for comparing the retrieved key signal component with said pre-selected code and for writing the information contained in said information signal component into said memory only if the retrieved key signal component corresponds to said code, and fourth means rendered effective upon reception of said interrogation signal for supplying the information stored in said memory in the form of a modulated signal that is receivable by said second station, said antenna means having an antenna electrically connected to said fourth means for emitting said modulated signal, and said fourth means including a pulse generator, a counter and a modulator, said memory having a data output connected to said generator for feeding information stored in the memory to said generator in the form of a digital signal when said memory is in its read mode, said generator being responsive to said digital signal for producing a further signal which is coded to contain the information read out of said memory and which is formed with serially occurring pulses, said counter being connected to said pulse generator for counting the pulses supplied by said generator and having an output connected to said memory for addressing different storage locations in said memory in accordance with the pulse count in the counter, and said modulator being connected to said generator to phase modulate said interrogating signal with said further signal to develop said modulated signal.