Abstract: A method for transferring data over a communication link from a first unit to a second unit, the link comprising a first portion across which the data is carried by the transmission of data packets at regular intervals, and a second portion between the first portion and the first unit over which the data is carried in a form that is not synchronised with the transmission of data packets over the first portion; the method comprising transmitting to the first unit synchronisation information regarding the times at which packets are to be transmitted over the first portion.

Abstract: A negotiation unit for operation in a communication system whereby a first communication unit may transmit data to a second communication unit by means of a protocol including the step of negotiating a parameter for use in the operation of the protocol by the transmission of a first negotiation message to the second communication unit and in response thereto the transmission of a second negotiation message from the second communication unit to the first communication unit, the negotiation messages being configured to be capable of including data defining a value for the parameter, the negotiation unit comprising: storage means for storing information on a criterion on the parameter, interception means for intercepting at least one of the negotiation messages directed towards one of the first and second communication units; and message analysis means for analysing the intercepted negotiation message and if the message includes a value for the parameter f) checking whether the stored criterion on the value is m

Abstract: A method of noise suppression to suppress noise in a signal containing background noise (314) in a communications path between a cellular communications network and a mobile terminal. The method comprises the steps of: estimating and up-dating a spectrum of the background noise (332, 334); using the background noise spectrum to suppress noise in the signal; generating an indication to indicate the operation of at least one of a discontinuous transmission unit (DTX) and a bad frame handling unit (BFI); and freezing estimating and up-dating of the spectrum of the background noise when the indication is present.

Abstract: A method of noise suppression to suppress noise in a signal containing background noise (314) in a communications path between a cellular communications network and a mobile terminal. The method comprises the steps of: estimating and up-dating a spectrum of the background noise (332, 334); using the background noise spectrum to suppress noise in the signal; generating an indication to indicate the operation of at least one of a discontinuous transmission unit (DTX) and a bad frame handling unit (BFI); and freezing estimating and up-dating of the spectrum of the background noise when the indication is present.

Abstract: A method of noise suppression to suppress noise in a signal containing background noise (314) in a communications path between a cellular communications network and a mobile terminal. The method comprises the steps of: estimating and up-dating a spectrum of the background noise (332, 334); using the background noise spectrum to suppress noise in the signal; generating an indication to indicate the operation of at least one of a discontinuous transmission unit (DTX) and a bad frame handling unit (BFI); and freezing estimating and up-dating of the spectrum of the background noise when the indication is present.

Abstract: A negotiation unit for operation in a communication system whereby a first communication unit may transmit data to a second communication unit by means of a protocol including the step of negotiating a parameter for use in the operation of the protocol by the transmission of a first negotiation message to the second communication unit and in response thereto the transmission of a second negotiation message from the second communication unit to the first communication unit, the negotiation messages being configured to be capable of including data defining a value for the parameter, the negotiation unit comprising: storage means for storing information on a criterion on the parameter, interception means for intercepting at least one of the negotiation messages directed towards one of the first and second communication units; and message analysis means for analysing the intercepted negotiation message and if the message includes a value for the parameter f) checking whether the stored criterion on the value is m

Abstract: A method for transferring data over a communication link from a first unit to a second unit, the link comprising a first portion across which the data is carried by the transmission of data packets at regular intervals, and a second portion between the first portion and the first unit over which the data is carried in a form that is not synchronised with the transmission of data packets over the first portion; the method comprising transmitting to the first unit synchronisation information regarding the times at which packets are to be transmitted over the first portion.

Abstract: A method which comprises forming a first noise reduction frame (18) containing speech samples; which is windowed by a first window function. For the windowed frame, noise reduction is performed for producing a second noise reduction frame (19; 45). A speech coding frame (44) to be formed comprises noise-reduced samples of at least two successive second noise reduction frames (45, 46), partly summed with one another. On the basis of said speech coding frame (44), a set of speech coding parameters pj are determined. A lookahead part (42) of the speech coding frame is at least partly formed of a first slope (41), the first slope (10, 41) comprising a set of most recent noise-reduced samples of the second noise reduction frame, not summed with the samples of any other second noise reduction frame. The method reduces the delay caused by speech coding and noise reduction.

Abstract: An improved method converts a first sampling rate of signal values to a second sampling rate, the second sampling rate being a non-integer multiple of the first sampling rate. The method includes the steps of: interpolating between successive signal values occurring at the first sampling rate to derive further signal values at an integer multiple sampling rate thereof, the integer multiple sampling rate falling within a range that is a greater than 0.5 and less than two times an integer multiple of the second sampling rate; employing a method of weighted average interpolation or decimation to derive from the signal values occurring at an integer multiple sampling rate of the first sampling rate, signal value magnitudes occurring at the integer multiple of the second signal sampling rate; and decimating the signal values at the integer multiple of the second sampling rate by an integer multiple factor to derive second sampling rate.

Abstract: The invention relates to echo cancelling methods used in telephone systems, more specifically to echo cancelling methods based on two filters. The echo cancelling method according to the invention employs two adaptive filters, namely, a main filter (10) and a background filter (50). The purpose of the background filter (50) is to make sure that the main filter (10) model stays correct. The main and background filter coefficients are updated on different conditions, and the residual signals (L.sub.-- RES1, L.sub.-- RES2) produced by the filters are compared to each other. The set of filter coefficients used for generating the echo canceller's output signal (S.sub.-- OUT) is selected on the basis of said comparison of the residual signals. The selection of the set of filter coefficients is carried out either by copying the background filter coefficients to the main filter or by interchanging the background and main filter functions.

Abstract: The invention concerns a voice activity detection device in which an input speech signal (x(n)) is divided in subsignals (S(s)) representing specific frequency bands and noise (N(s)) is estimated in the subsignals. On basis of the estimated noise in the subsignals, subdecision signals (SNR(s)) are generated and a voice activity decision (V.sub.ind) for the input speech signal is formed on basis of the subdecision signals. Spectrum components of the input speech signal and a noise estimate are calculated and compared. More specifically a signal-to-noise ratio is calculated for each subsignal and each signal-to-noise ratio represents a subdecision signal (SNR(s)). From the signal-to-noise ratios a value proportional to their sum is calculated and compared with a threshold value and a voice activity decision signal (V.sub.ind) for the input speech signal is formed on basis of the comparison.

Abstract: The invention relates to a method of noise suppression, a mobile station and a noise suppressor for suppressing noise in a speech signal. The suppressor comprises means (20, 50) for dividing the speech signal into a first amount of subsignals (X, P), which subsignals represent certain first frequency ranges, and suppression means (30) for suppressing noise in a subsignal (X, P) based upon a determined suppression coefficient (G). The noise suppressor further comprises recombination means (60) for recombining a second amount of subsignals (X, P) into a calculation signal (S), which represents a certain second frequency range, which is wider than the first frequency ranges and determination means (200) for determining a suppression coefficient (G) for the calculation signal (S) based upon the noise contained by it.

Abstract: A method for adaptation to an echo location in an echo canceller comprising an output port, an input port, an adjustable delay unit (43) compensating for the pure delay component in the echo path between the echo location and the output port of the echo canceller, a digital filter (40) calculating, from a signal outgoing to the echo path, an echo location estimate which is shorter than the maximum allowed duration of the echo path. The echo location is determined by calculating the echo path location at which there is a high correlation between the signal outgoing to the echo path and the returned echo. The correlation is calculated in a sliding window having the length of the digital filter.