Abstract: A multi-channel transcoder with rate adapter converts the data rate of GSM and PSTN network data in a multi-channel network. A transcoder having echo-cancellation features uses the robust voice activity detection functions of the GSM transcoder functions to enhance the accuracy of echo-cancellation of near-end signals. A method for decoding a GSM signal in which the transmission of the audio data over the network is commenced prior to the completing of the decoding process. A transcoder unit having rate adaption and echo-cancellation with improved decoding is implemented in a single DSP and processes multiple traffic channels simultaneously.

Abstract: Disclosed is a modem including a transmitter having a convolutional encoder for transforming each group interval digital data into an expanded bit sequence having symbol-selecting bits and subset-selecting bits forming a plurality of bit groups, with each bit group designating a 2-dimensional subset and the symbol-selecting bits being used to select one 2-dimensional symbol from each of the selected subsets, the transmitter further providing modulation of a carrier signal, and a receiver wherein synchronization of received frames of subset-selecting bits is provided by applying a parity check equation to a plurality of possible received frames of subset-selecting bits.

Abstract: Disclosed is a modem including a transmitter having a convolutional encoder for transforming each group interval digital data into an expanded bit sequence having symbol-selecting bits and a frame of subset-selecting bits forming a plurality of bit groups, with each bit group designating a 2-dimensional subset and the symbol-selecting bits being used to select one 2-dimensional symbol from each of the selected subsets, the transmitter further providing modulation of a carrier signal, and a receiver wherein a commonality-seeking, branch cost calculator determines the candidate branch associated with the minimum cost N-dimensional symbol subset for each coset and a Viterbi decoder which determines the maximum likelihood path from a plurality of surviving paths formed from branches selected from the candidate branches.

Abstract: A system for transferring echo cancellation data is provided. The system includes an echo cancellation element, which has echo cancellation algorithm data that has been determined for a predetermined telecommunications channel. The system also includes another echo cancellation element. An echo cancellation controller module is connected to the echo cancellation element and the other echo cancellation element. The echo cancellation controller module retrieves the echo cancellation algorithm data from the echo cancellation element, and transfers the echo cancellation algorithm data to the other echo cancellation element when a telecommunications channel is transferred from a cell to another cell.

Abstract: An apparatus for processing wireless telecommunications is provided. The apparatus includes an echo canceller module. An echo canceller module controller is connected to the echo canceller module. The echo canceller module controller can receive echo canceller data, and can turn the echo canceller module on when the echo canceller data indicates that echo cancellation is required, such that echo cancellation may be controllably turned on only when it is needed.