摘要:
Methods and apparatus are provided for secure communication techniques in a communication system. The system can include a first device which communicates with a second device over a channel. A security association can be established during a first session between the devices via an asymmetric key exchange. The security association comprises a Traffic Encryption Key (TEK) and a first state vector. The TEK comprises a shared, secret symmetric key. The security association is stored in each of the devices for use during a second session between the devices to expedite security association establishment during call set-up of the second session. The security association can be associated with the second device in the first device, and with the first device in the second device. An updated state vector can be generated at the first device. A second session can be established between the first device and the second device by using the TEKs from the first session and the updated state vector. The security association can be used to encrypt voice packets being sent from the first device to the second device. The security association and updated state vector can then be used to decrypt the encrypted voice packets received by the second device from the first device.
摘要:
An apparatus (213) and corresponding methods (FIG. 7) to facilitate maintaining crypto synchronization while processing communication signals in a communication unit includes a vocoder (215) configured to convert input audio band signals to vocoder output frames; a crypto processor (217) configured to encrypt the vocoder output frames to provide encrypted output frames; and a synchronizer (219) configured to substitute in a predetermined manner synchronization information corresponding to an encryption state of the crypto processor for a portion of the encrypted data in a portion of the encrypted output frames to provide resultant output synchronization frames suitable for synchronizing a decryption process at a target communication unit.
摘要:
Techniques are provided for secure group communications in a wireless dispatch system which includes a group of devices. The group of devices can include a first secure device which communicates with a plurality of second secure devices over a channel.
摘要:
A telephone (310) and a method for providing outbound audio when the telephone is operating in a speakerphone mode. A first data unit (350) including a first unit type identifier (360) can be received by the telephone. The first unit type identifier can be an indicator of a type of audio data contained in the first data unit. For instance, the first unit type identifier can indicate whether the audio data is music or non-music audio data. If the first unit type identifier has a first value, for example a value indicating that the audio data is music data, unmuted outbound audio reproduced from the first data unit can be provided and voice activity detection can be disabled. Additionally, inbound audio can be muted.
摘要:
A method of scaling polyphony can include identifying music data to be played (415), wherein the music data indicates instruments to be used and each instrument has an assigned priority. A measure of polyphony needed to play the music data can be compared with polyphony of a sound generating device (425). If the measure of polyphony exceeds the polyphony of the sound generating device, the music data can be played without using one or more instruments indicated by the music data according to the assigned priorities (440, 460).
摘要:
The invention concerns a method (300) and system (100) for improving voice quality of a vocoder (138, 158). The method includes the steps of monitoring (312) a pitch of a voice signal (400) at a transmitting unit (110); when the pitch of the voice signal reaches a predetermined threshold (840), shifting (326) the pitch of the voice signal to at least a portion of a predetermined range (810); transmitting (338) the pitch-shifted voice signal to a receiving unit (112); and at the receiving unit, reshifting (342) the pitch-shifted voice signal to a level that compensates the step of shifting the pitch of the voice signal at the transmitting unit.
摘要:
Human hearing perceives loudness based on critical bands corresponding to different frequency ranges. As a sound's frequency spectrum increases beyond a critical band into a previously unexcited critical band, the perception is that the sound has increased in loudness. To take advantage of this principle, a filter is applied to a speech signal so as to expand the formant bandwidths of formants in the speech sample.
摘要:
Methods for personalized listening which can be used with an earpiece are provided. A method includes capturing ambient sound from an Ambient Sound Microphone (ASM) of an earpiece partially or fully occluded in an ear canal, monitoring the ambient sound for a target sound, and adjusting by way of an Ear Canal Receiver (ECR) in the earpiece a delivery of audio to an ear canal based on a detected target sound. A volume of audio content can be adjusted upon the detection of a target sound, and an audible notification can be presented to provide a warning.
摘要:
At least one exemplary embodiment is directed to a method for personalized listening which can be used with an earpiece is provided that can include capturing ambient sound from an Ambient Sound Microphone (ASM) of an earpiece partially or fully occluded in an ear canal, monitoring the ambient sound for a target sound, and adjusting by way of an Ear Canal Receiver (ECR) in the earpiece a delivery of audio to an ear canal based on a detected target sound. A volume of audio content can be adjusted upon the detection of a target sound, and an audible notification can be presented to provide a warning.
摘要:
A speech filter (108) enhances the loudness of a speech signal by expanding the formant regions of the speech signal beyond a natural bandwidth of the formant regions. The energy level of the speech signal is maintained so that the filtered speech signal contains the same energy as the pre-filtered signal. By expanding the formant regions of the speech signal on a critical band scale corresponding to human hearing, the listener of the speech signal perceives it to be louder even though the signal contains the same energy.