A paging system is provided for transferring data and voice messages to a unique address of a paging receiver. The system includes a paging controller, an encoder, a transmitter, and a paging receiver. The paging controller receives voice and data information from an entry device. The encoder, coupled to the paging controller, encodes the voice and data information into a composite paging signal designated for the unique address of the paging receiver. The composite paging signal is transmitted to the paging receiver by the transmitter. The paging receiver receives and decodes the composite paging signal to receive the data and voice messages. The data are displayed simultaneously with the voice message being furnished to the paging receiver used. In one embodiment, a PBX system automatically provides the data message in the form of a telephone number. The paging system automatically provides the telephone number of the sender along with the voice message to the paging receiver user.
When a mobile station (4) staying in a first paging zone (1) begins communication with a network through a base station by using a paging channel (P1) which is specific to the paging zone (1) and one of speech channels (S11-S20), and finishes the communication in a paging zone (2) after moving from the zone (1) to the zone (2), the paging channel in the waiting state after the speech in the zone (2) is not (P1), but (P2) which is specific to the zone (2). In order to assure that paging channel (P2), a base station in the zone (2) informs the mobile station (4) the paging channel (P2) which should be used in the waiting state in the disconnect signal. Thus, no switching of a paging channel in waiting state because of low receive level of the paging channel signal is necessary, and a quick service after previous speech is possible.
A portable wireless voice message transmitter over packet switched network for transmitting a voice message is provided. The transmitter is capable of transmitting a voice message and text-based information when a user makes an emergency call to a special address with which the text-based information is associated. The transmitter includes text-based information setting circuit for setting text-based information, a first memory for storing the text-based information, a special address setting circuit for setting a special address which is associated with the text-based information and a second memory for storing the special address. The transmitter also includes a microphone for inputting a voice message, a third memory for storing the voice message, a destination setting circuit for setting a destination, a transmission start key operable by a user for generating a transmission start signal and a transmitter circuit responsive to the transmission start signal for transmitting the voice message stored to the destination address. When the destination address is coincident with the special address stored in the first memory, the transmitter circuit transmits the text-based information as well as the voice message to the destination address so that the message recipient receives both the voice message and the text-based information.
A radio pager receives from a base station a paging signal consisting of an address code group and a message code group including musical note data. The receiver separates the received paging signal into the address code group and message code group. Further, the receiver separates the message code group into message data and musical note data by using a melody start symbol and a melody end symbol. Then, the receiver generates melody frequencies corresponding to the consecutive musical note data, modulates the melody frequencies to output a melody, and drives a speaker therewith.
Error detection and correction of a received message, such as a digitized voice message is achieved by generating (318) interpolated vectors for each error vector corresponding to a codebook index in a sequence of codebook indexes representing parameters of portions of the message. A plurality of error corrected candidate vectors for the vector corresponding to the codebook index in error, are generated (322,324,326) by flipping one bit in a sequence of bits representing the codebook index in error. The error corrected candidate vector which has a minimal difference from its corresponding interpolated vector is used (338) to replace the error vector. In the case of digital voice, the vectors are spectral vectors which represent spectral information for a time sample of a voice message. An ordering property of vector components is exploited to detect errors in a received codebook index without parity bits.
An audio amplifier for providing a power boost for telephone-sourced audio signals that drive one or more paging speakers employs a class D amplifier and a state variable feedback network, which monitors voltage and current levels of an audio output filter to which the paging speakers are coupled, so as to adjust the operation of the amplifier circuit, as necessary, to compensate variations in the speaker loading of the audio output filter. The class D amplifier includes a pulse width modulator, which controls the switching of a power H-bridge-configured switching circuit. The switching circuit sources and sinks current with respect to the paging speaker load. The output of the power bridge switching circuit is a high energy square wave-type signal, which is filtered in a downstream audio filter to remove the switching transients and preserve the desired voice paging signal for application to the paging speakers. The state variable feedback network monitors variations in current flow and voltage at a plurality of circuit locations of the audio filter circuit and sums the monitored variations to produce an error signal, which is fed back to the input of the voice paging amplifier circuit and combined with the audio input signal.
