Abstract: A paging system includes a receiver adapted for receiving paging signals at a fixed bit rate of N.multidot.R where N is an integer and R is a basic bit rate. A transmitter transmits at the N.multidot.R bit rate, N being adjustable to accommodate any signal for any particular receiver. The transmitter bit rate is selected according to serial data received from a telephone exchange with a message to be transmitted. The transmitter has a degree indicating system producing a first signal representative of a degree N when it receives a signal which is representative of a bit rate N.multidot.R. It has interleaving means for N-degree interleaving of input data having the bit rate N.multidot.R, in response to the first signal, to produce an interleaved signal; and transmitting means for transmitting said interleaved signal. The receiver has means for receiving a signal whose bit rate is N.multidot.

Abstract: In a radio display pager, each character of a received multi-character message is checked for error. A first message arrival or a first receive message is stored in a temporary memory and thereafter rewritten into one of main memories when the next message or second message arrival is received. The temporary memory stores the most recent message arrival and the main memories store a plurality of like messages, according to their successive order of earlier arrivals. Each of the messages in both memories contain both error-free and error-containing characters. The characters stored in the temporary memory respectively correspond in position to the characters stored in each of the main memories. A comparison is made between each error-free character in the temporary memory and each of the positionally corresponding error-free characters in one of the main memories in order to detect a match and mismatch.

Abstract: A paging receiver is capable of receiving message data. The receiver includes a data set and a hold circuit, the output logic of which is inverted in response to the detection of a control signal which follows a paging number individually assigned to that receiver. The receiver is inhibited and excluded from or enabled and restored into a data service which is provided in response to a common or group call number for paging many and unspecified receivers. The inhibit or enable signal is provided by the output of the data set and hold circuit. The data set and hold circuit are powered by a power source which is different from a main power source of the receiver. The receiver determines whether or not the power source associated with the data set and hold circuit is present and, if it is not present, the receipt of the data service based on the common number is inhibited.

Abstract: A paging receiver includes an improved battery saving circuit which reduces battery usage by powering the radio section and the waveform shaping circuitry only during intervals which include address codewords specific to the given receiver group. Power is not supplied during intervals containing synchronization code signals other than during the first such interval directly following the preamble code. Upon detecting a preamble code during said intervals, power is supplied continuously for a time period sufficient to encompass the synchronization code interval.

Abstract: A selective calling radio paging receiver includes a battery saving controller which activates the high power drain unit of the receiver at periodic intervals for allowing the detection of a preamble contained in a received digital paging signal and deactivates it for a period longer than the period of activation for power savings purposes. The power saving is disabled in response to the detection of a preamble for continued power activation to permit a sync detector and an address detector to be operated in succession. A window pulse is generated in synchronism with the clock timing of the received digital signal so that its binary level transition is time coincident with each window pulse. If noise occurs in the received signal, binary level transitions occurs which are out of coincidence with window pulses. The time-coincident binary level transitions and the noncoincident binary level transitions are counted to give first and second counts, respectively.

Abstract: A synchronizing circuit for synchronizing the phase of a clock signal to the phase of a received digital signal includes a phase monitoring circuit for detecting, during each bit period of the digital signal, the phase advance of delay of the clock signal relative to the digital signals. A phase signal is outputting which is indicative of the phase advance or delay of the clock signal. A phase control circuit responds to the phase signal to either advance, delay or leave unchanged the phase of the clock signal with respect to the received digital signal. An inhibiting circuit coupled to the phase control circuit operates to prevent the phase control circuit from reversing the sense of the phase adjustment from advance to delay or from delay to advance in consecutive bit positions, interposing instead one bit position during which the phase of the clock signal is left unadjusted.

Abstract: A selective paging receiver with message display has a receiver section, a number setting circuit, a paging number detector, and a display panel. The receiver section receives paging signals sent to the paging receiver, and recovers a paging number data signal and a message data signal from the paging signals. The message data signal includes both individual message data for the paging receiver, and common message data for the paging receiver in common with a preselected group of similar receivers. A number setting circuit assigns both a preselected individual paging number and a preselected common paging number to the receiver. The paging number detector searches for the individual paging number in a particular group time frame of the paging number signal. This time frame corresponds to a paging receiver group to which the paging receiver belongs. The paging number detector conducts a parallel search for the common paging number without regard for the particular group time frame.

Abstract: A radio pager receiver has a memory with a message area, and an additional area and a message processor for processing a message signal into messages and to store the messages in the message area. A specific datum is written (S6) in the additional area by the message processor. Although the message processor and the memory are activated by main electric power of a power supply circuit, only the memory is backed up by backup electric power of a backup power source. When the memory and the message processor are activated after once deactivated, the message processor judges (S2) whether or not the specific datum is correctly kept. The message processor controls display (S3 and S4) of a result of judgement. In the message area and the additional area, entries may be erased (S8) by the message processor when the specific datum is not correctly kept.

Abstract: A radio paging system, comprising a transmitting base station and a paging receiver with a battery-saving function. The paging receiver operates intermittently at different repetition periods, depending on the call traffic density. When there are fewer calls, the receiver operates less frequently, in order to avoid unnecessary operation and consequent battery drain. When there is a call to be sent, the period between attempted detections of a preamble code word is shortened. The receivers then lengthen the period for detecting a message, and receive a sync code word, followed by an address code word, which alerts the particular receiver being paged, an alert tone being generated. The message ends with a battery saving code word and ending code word. The battery saving code word alerts the receivers to lengthen the period between attempted detections of the preamble code word. The variation in length of periods between attempted detection is a battery-saving feature.

Abstract: A pager with a passive display, for example, a liquid crystal display, also has a sensor for sensing ambient light levels. The display is automatically illuminated when the ambient light level falls below a given threshold and the sensor is then either altered to detect a higher light level or disabled for a given time period so that the illumination does not falsely affect the sensor.