Abstract: The invention provides a method and system for dynamically estimating background noise. The system includes a portable communication device, a vocoder, and a voice activated detector. Based on information received by the portable communication device, the vocoder determines parameters related to incoming information including a voicing mode indicative of the periodicity of incoming information. The voice activated detector then compares the voicing mode to a threshold to determine whether a background noise estimate should be updated.

Abstract: A communication system (100) for bridging talk groups includes private network communication devices (102) operating within a private network system, and public network communication devices (110, 122, 112) operating within a public network system. At least one communication subsystem (104) is operable with both the private and public network systems. The communication subsystem (104) relays information between the private network communication devices (102) and the public network communication devices (110, 122, 112).

Abstract: A mobile communication device (102) receives information in a broadcast control channel (108) including a page message (108). The mobile communication device measures certain parameters (210) of the control channel, such as received signal strength, channel quality, and the present automatic gain setting. These parameters are scored and weighted (300) to produce a signal quality metric (314) to determine the duration of time the mobile communication device can remain in a low power state to conserve battery charge before checking for page alert message in the broadcast control channel next.

Abstract: A system, method and computer readable medium are provided for segmenting a cache that is shared by multiple processors. According to the method, a first segment of the cache is allocated to a first processor and a second segment of the cache is allocated to a second processor. An execution time of at least one task on the first processor is monitored. If the execution time of the at least one task is greater than an allowed execution time minus a predetermined margin, the size of the first segment of the cache that is allocated to the first processor is increased. In one preferred method, if the execution time of the at least one task is significantly less than the allowed execution time minus the predetermined margin, the size of the first segment of the cache that is allocated to the first processor is decreased.

Abstract: Location information is acquired through a public network system (102, 106) and transferred over to a private network system (104, 108) in order to improve location accuracy and reduce search time for a two-way radio (104).

Abstract: A communication system (100) for bridging talk groups includes private network communication devices (102) operating within a private network system, and public network communication devices (110, 122, 112) operating within a public network system. At least one communication subsystem (104) is operable with both the private and public network systems. The communication subsystem (104) relays information between the private network communication devices (102) and the public network communication devices (110, 122, 112).

Abstract: A system, method and computer readable medium are provided for segmenting a cache that is shared by multiple processors. According to the method, a first segment of the cache is allocated to a first processor and a second segment of the cache is allocated to a second processor. An execution time of at least one task on the first processor is monitored. If the execution time of the at least one task is greater than an allowed execution time minus a predetermined margin, the size of the first segment of the cache that is allocated to the first processor is increased. In one preferred method, if the execution time of the at least one task is significantly less than the allowed execution time minus the predetermined margin, the size of the first segment of the cache that is allocated to the first processor is decreased.

Abstract: Location information is acquired through a public network system (102, 106) and transferred over to a private network system (104, 108) in order to improve location accuracy and reduce search time for a two-way radio (104).

Abstract: The invention relates to a system and method for use in wireless packet data mode communications for enabling communication between a source device (102a) and one or more target devices (102b) with a reduced set-up time. The invention captures in a control structure (600), one or more communication parameters (602-608) during the set up of the source device (102) and a base station (106). Then the control structure (600) is transmitted to the one or more target devices (102b) during the period of the source device's (102a) configuration and is utilized to configure the one or more target devices (102b) to communicate with the source device (102a) via the base station (106), thus reducing the total time required to set-up the communications.

Abstract: The invention provides a method and system for dynamically estimating background noise comprising. The system includes a portable communication device, a vocoder, and a voice activated detector. Based on information received by the portable communication device, the vocoder determines parameters related to incoming information including a voicing mode indicative of the periodicity of incoming information. The voice activated detector then compares the voicing mode to a threshold to determine whether a background noise estimate should be updated.

Abstract: The invention relates to a system and method for use in wireless packet data mode communications for enabling communication between a source device (102a) and one or more target devices (102b) with a reduced set-up time. The invention captures in a control structure (600), one or more communication parameters (602-608) during the set up of the source device (102) and a base station (106). Then the control structure(600) is transmitted to the one or more target devices (102b) during the period of the source device's (102a) configuration and is utilized to configure the one or more target devices (102b) to communicate with the source device(102a) via the base station (106), thus reducing the total time required to set-up the communications.

Abstract: A portable communication device (104), such as a cellular telephone, is operable in a speakerphone mode. The communication device uses a digital communication scheme, and both receives and generates vocoded signals. The speakerphone provides half duplex operation to eliminate echo. When voice activity is detected, the device activates a speaker and mutes a microphone to avoid echo. When no voice activity is detected in the received signal, the speaker is muted and the microphone activated. To determine when speech activity is present in the received signal, a novel voice activity detection (VAD) algorithm is used which takes advantage of parameters provided as part of the received vocoded signal. The new voice activity algorithm includes calculating a staggered average of the frame energy value for a sequence of received frames, and determining if the staggered average value exceeds a threshold.

Abstract: A digital signal processor (100) receives a digitally vocoded signal (102), and calculates a staggered average value (404) from the frame energy of each received frame, or the product of the frame energy and a voicing value. While the staggered average value is above a threshold voice indicator value, speech is declared present.

Abstract: In a communication device, a decoded audio signal is evaluated by a detection function (112). Two portions of the decoded audio signal spectrum are evaluated, a ringback band (206), and the remaining band(s). The signal strength in the ringback band is measured against a preselected ringback energy threshold level and the non-ringback signal strength is measured against a voice energy threshold level. Only if the ringback energy is above the ringback energy threshold level and the non-ringback band energy is below the voice energy threshold level will a ringback filter be applied to the audio signal.

Abstract: A digital communications system (10) includes a transmitting apparatus (12) and a receiving apparatus (14). In addition to a primary information signal (16), messages and control signals (24) are communicated for use by the equipment. To avoid the use of dedicated frequency spectrum, control channel time slots, or the degradation of forward error correction of the encoded information signal, the transmitting apparatus determines the occurrence of a silence period (28) in the information signal, then inserts the message or control signal information into the silence period. The resulting composite signal is transmitted to the receiving apparatus where message and control information is removed for use by the receiving equipment, leaving the information signal intact.

Abstract: An encoder provides enhanced data encoding by manipulating encoding formats for standard data to effect transfer of additional data (300). Data recovery of the additional data is provided through a corresponding detection of decoding formats for decoding the standard data (400).

Abstract: An electronic device (110) provides equalization and/or compensation for a coupled audio accessory device (120). The audio accessory device (120) has a memory (220) that contains equalizer parameters (304, 308, 310, 314) which helps in characterizing its audio response or impact on audio signals within the electronic device (110). When the audio accessory device (120) is coupled to the electronic device (110), the electronic device (110) reads the equalizer parameters (304, 308, 310, 314) from the audio accessory's memory (220) and processes audio signals with equalization and/or compensation based at least in part on the equalizer parameters (304, 308, 310, 314).

Abstract: Briefly, according to the invention, a receiver (100) for receiving and decoding a carder signal is described. A carrier signal is modulated with an information signal which has one of a plurality of formats. The receiver includes a circuit (104) for receiving and demodulating the carrier signal to produce a demodulated signal. The receiver (100) also includes a digital signal processing subsystem (108) for calculating the correlation function of the demodulated signal and based on this correlation function classifies the format of the demodulated signal. A decoder (118) is further included in the receiver (100) to decode the demodulated signal once it has been classified.

Abstract: A method of providing an inband secondary channel for a data modem includes encoding the main channel data using a convolutional encoder so that main channel data symbols are selected from a first constellation. The secondary channel data are encoded using a differential encoder and secondary channel data symbols are selected from a second constellation. The transmission of the main channel symbols takes place during 48 frames of a 49 frame master frame. The differentially encoded secondary channel data symbols are transmitted during the remaining frame. The symbols of the secondary channel constellation are selected to have a higher average energy than those of the main channel data so that the secondary channel is easily detected and may be used to obtain frame synchronization for the modem after brief dropouts without having to retrain the modem.

Abstract: Disclosed is a modem including a transmitter having a convolutional encoder for transforming each time unit digital data into an expanded bit sequence having symbol-selecting bits and subset-selecting bits, the transmitter further providing modulation of a carrier signal and a receiver wherein a Viterbi decoder determines the maximum likelihood path through a trellis from a plurality of surviving paths using a wraparound memory wherein in each addressable location indexed to a current state of a surviving path there is stored a previous state of that surviving path.