Abstract: A method of for aliasing suppression in a sub-band speaker-phone system, comprising receiving an analog audio signal from a near end analog audio input interface, converting said analog audio signal into a near end digital audio signal using an A2D; receiving N?2 sub-bands decoded digital audio data from a far-end, merging said N?2 sub-bands decoded digital audio data into a wideband (WB) decoded digital audio data to be converted by D2A unit and provided to analog audio output interface; splitting said near-end digital audio signal into N?2 near-end sub-bands digital audio signals; subtracting a simulated digital signal from said sub-band digital audio signal, wherein said simulated digital signal is created by an echo cancelling unit; and applying dynamic anti aliasing suppression (DAAS) with varying aggressiveness on each of said N?2 near-end sub-band digital audio signals.

Abstract: A method for reducing the transition rate of a pulse width modulated signal representing an original signal having a predetermined frequency range of interest and producing an output signal, the method including the steps of: combining pulses from a predetermined number of consecutive frames into a combined pulse; and positioning the combined pulse within the predetermined number of consecutive frames, such that the output signal has substantially the same Fourier Transform phase as the pulse width modulated signal, for at least the predetermined frequency range of interest of the original signal.

Abstract: A method of maintaining signal convergence of a transmitter and a receiver of an adaptive differential pulse code modulated (ADPCM) communication system during discontinuous transmission, by generating synchronized comfort noise frame in the transmitter and in the receiver during quiet periods and mutually updating the receiver's decoder and encoder on their states.

Abstract: A method for reducing the transition rate of a pulse width modulated signal representing an original signal, and thus reducing energy losses of devices such as class D amplifiers stimulated by the signal, while decreasing the jitter and thus the SNR of the output low passed signal. Within the method every R pulses of a signal having a frame duration of M, are summed to receive frames of R*M duration having a single pulse. Then, the odd pulses are mirrored within their respective time frames, so that each odd pulse is attached to the following even pulse. The combined pulse, which occurs in a window having a duration of 2*R*M is then optionally re-positioned within its time frame. The repositioning can be designed so as to position the pulse within the 2*R*M window, having the same moment as the original signal, or to receive a signal having the same phase of the Fourier transform as the original signal, at least for the frequency range of interest of the original signal, such as the low frequencies.

Abstract: An apparatus and method for testing a unit comprising of digital-to-analog converter and an analog-to-digital converter, by determining offset and gain-difference between the two converters, and then testing the pair using a wide range of values. During the testing, the gain-control is injected into the unit in order to set the unit size of one of the converters, and the offset is subtracted from the output signal of the unit, so that the transfer functions of the converters are matched. The gain-control is optionally determined using the successive approximation algorithm.

Abstract: The present invention relates to a method of replacing a sequence of one or more commands from a routine in a ROM of a device using a RAM. The method allows replacing part of a routine, for example a single command, while continuing to use the rest of the commands of the routine from the ROM. In an exemplary embodiment of the invention, a single command is replaced by adding only two additional commands or four additional commands as overhead in the replacement process.