Abstract: During operation an input signal to be coded is received and coded to produce a coded audio signal. The coded audio signal is then scaled with a plurality of gain values to produce a plurality of scaled coded audio signals, each having an associated gain value and a plurality of error values are determined existing between the input signal and each of the plurality of scaled coded audio signals. A gain value is then chosen that is associated with a scaled coded audio signal resulting in a low error value existing between the input signal and the scaled coded audio signal. Finally, the low error value is transmitted along with the gain value as part of an enhancement layer to the coded audio signal.

Abstract: A method for decoding an audio signal in a decoder having a CELP-based decoder element including a fixed codebook component, at least one pitch period value, and a first decoder output, wherein a bandwidth of the audio signal extends beyond a bandwidth of the CELP-based decoder element. The method includes obtaining an up-sampled fixed codebook signal by up-sampling the fixed codebook component to a higher sample rate, obtaining an up-sampled excitation signal based on the up-sampled fixed codebook signal and an up-sampled pitch period value, and obtaining a composite output signal based on the up-sampled excitation signal and an output signal of the CELP-based decoder element, wherein the composite output signal includes a bandwidth portion that extends beyond a bandwidth of the CELP-based decoder element.

Abstract: A method for decoding an audio signal having a bandwidth that extends beyond a bandwidth of a CELP excitation signal in an audio decoder including a CELP-based decoder element. The method includes obtaining a second excitation signal having an audio bandwidth extending beyond the audio bandwidth of the CELP excitation signal, obtaining a set of signals by filtering the second excitation signal with a set of bandpass filters, scaling the set of signals using a set of energy-based parameters, and obtaining a composite output signal by combining the scaled set of signals with a signal based on the audio signal decoded by the CELP-based decoder element.

Abstract: A method for estimating a parameter for low bit rate stereo transmission that includes deriving estimate of any time delay between left and right audio channels in a multi-channel signal from a time delay subsystem. A cross-correlation between the left and right audio channels in the time delay subsystem is employed. Thereafter a normalized cross-correlation within an inter-channel intensity difference (IID) processor is employed before deriving estimate of panning gains for the left and right audio channels from the IID processor.

Abstract: A method for encoding audio frames by producing a first frame of coded audio samples by coding a first audio frame in a sequence of frames, producing at least a portion of a second frame of coded audio samples by coding at least a portion of a second audio frame in the sequence of frames, and producing parameters for generating audio gap filler samples, wherein the parameters are representative of either a weighted segment of the first frame of coded audio samples or a weighted segment of the portion of the second frame of coded audio samples.

Abstract: A method for processing an audio signal including classifying an input frame as either a speech frame or a generic audio frame, producing an encoded bitstream and a corresponding processed frame based on the input frame, producing an enhancement layer encoded bitstream based on a difference between the input frame and the processed frame, and multiplexing the enhancement layer encoded bitstream, a codeword, and either a speech encoded bitstream or a generic audio encoded bitstream into a combined bitstream based on whether the codeword indicates that the input frame is classified as a speech frame or as a generic audio frame, wherein the encoded bitstream is either a speech encoded bitstream or a generic audio encoded bitstream.

Abstract: An encoding apparatus comprises a frame processor (105) which receives a multi channel audio signal comprising at least a first audio signal from a first microphone (101) and a second audio signal from a second microphone (103). An ITD processor 107 then determines an inter time difference between the first audio signal and the second audio signal and a set of delays (109, 111) generates a compensated multi channel audio signal from the multi channel audio signal by delaying at least one of the first and second audio signals in response to the inter time difference signal. A combiner (113) then generates a mono signal by combining channels of the compensated multi channel audio signal and a mono signal encoder (115) encodes the mono signal. The inter time difference may specifically be determined by an algorithm based on determining cross correlations between the first and second audio signals.

Abstract: An apparatus and method for synchronization between uncoordinated Time Division Duplex (TDD) communication networks includes a first step (300) of measuring an interference level on channels available to a base station. A next step (302) includes choosing the channel having the lowest interference level. A next step (304) includes determining that the interference is from a base station. A next step (306) includes calculating an interference profile over the frame cycle. A next step (308) includes establishing a peak interference level. A next step (310) includes aligning the base station frame timing in response to the peak interference level.

Abstract: Apparatus (119) for encoding at least one parameter associated with a signal source for transmission over k frames to a decoder comprises a processor (119) which is configured in operation to assign a predetermined bit pattern to n bits associated with the at least one parameter of a first frame of k frames and set the n bits associated with the at least one parameter of each of k?1 subsequent frames to values, such that the values of the n bits of the k?1 subsequent frames represent the at least one parameter. The predetermined bit pattern indicates a start of the at least one parameter.

Abstract: An apparatus and method for synchronization between uncoordinated Time Division Duplex (TDD) communication networks includes a first step (300) of measuring an interference level on channels available to a base station. A next step (302) includes choosing the channel having the lowest interference level. A next step (304) includes determining that the interference is from a base station. A next step (306) includes calculating an interference profile over the frame cycle. A next step (308) includes establishing a peak interference level. A next step (310) includes aligning the base station frame timing in response to the peak interference level.

Abstract: In a selective signal encoder, an input signal is first encoded using a core layer encoder to produce a core layer encoded signal. The core layer encoded signal is decoded to produce a reconstructed signal and an error signal is generated as the difference between the reconstructed signal and the input signal. The reconstructed signal is compared to the input signal. One of two or more enhancement layer encoders selected dependent upon the comparison and used to encode the error signal. The core layer encoded signal, the enhancement layer encoded signal and the selection indicator are output to the channel (for transmission or storage, for example).

Abstract: During operation an input signal to be coded is received and coded to produce a coded audio signal. The coded audio signal is then scaled with a plurality of gain values to produce a plurality of scaled coded audio signals, each having an associated gain value and a plurality of error values are determined existing between the input signal and each of the plurality of scaled coded audio signals. A gain value is then chosen that is associated with a scaled coded audio signal resulting in a low error value existing between the input signal and the scaled coded audio signal. Finally, the low error value is transmitted along with the gain value as part of an enhancement layer to the coded audio signal.

Abstract: A method of enhanced tandem communication is provided between at least a first portion of a network suitable for voice communications and a second portion of a network suitable for voice communications. During operation, two representations of an encoded signal are transmitted from the first portion of a network. The two representations comprise the encoded signal produced by a first codec and a parameter translation of the first encoded signal into an encoded signal compatible with a single common compressed voice codec (CCVC) format.

Abstract: The invention encompasses a method of preparing data for transmission, which method comprises: multiplexing data from a plurality of sources (S1, . . . Si, . . . Sn), the multiplexing comprising, for at least one source (Si), classifying the data from the source (Si) into two or more classes (C1,f.Cj, . . . Cm) according to the data's priority, and mapping data from the sources into positions in a data structure (D) according both to the class (Cj) of the data and to a further priority assigned to the source (Si) from which the data originated, the division of data into classes (C1, . . . Cj, . . . Cm) and/or the prioritization of the sources (S1, . . . Si, . . . Sn) being done according to the potential impact of transmission errors on the data; and sub-dividing the data in the data structure (D) into frames while preserving the relative prioritization of the data. The sources may be various multi-media sources.

Abstract: A method as shown in FIG. 2 for allocating resources in a radio communications system having a plurality of communications resources for at least one receiver and transmitter to communicate over where the communications resources have signal levels which vary due to a multipath environment resulting in periods of poor communication quality over at least one particular communications resource including measuring at a first receiver a parameter indicative of a quality of communications between the first receiver and a first transmitter over a currently assigned communications resource and determining whether to allocate a different communications resource based on the measured parameter in order to effectively reduce periods of poor communications quality between the first receiver and the first transmitter.