Audiocodes Ltd.

Dsp Group Limited

Felix Flomen

Leon Bialik

Oren Klimker

Ilan D Shallom

Nitay Shiran

Raziel Haimi-Cohen

Omri Paiss

Device, system, and method of Voice over Internet Protocol (VoIP) communications, and particularly of Real Time Protocol (RTP) communication. In order to improve quality-of-service or quality-of-experience for a group of VoIP calls that are served by a VoIP router, each VoIP transmitter implements and adds a pseudo-random waiting-period prior to transmitting each outgoing RTP packet, or otherwise re-orders or mixes or shuffles the order of channels of RTP packets that are buffered or queued for transmission. Accordingly, no particular VoIP channel suffers from repeated drops of its RTP packets at the VoIP router. Additionally, VoIP network analyzers operate to measure the overall VoIP network overuse, or the average RTP packet loss rate of multiple VoIP channels, based on measuring RTP packet loss rate of a single VoIP channel which enforces a random pre-transmission waiting-period.

System, method, and device of RTP packet transmission for VoIP channels

System, device, and method of RTP packet transmission and analysis of voice-over-IP communications

Device, system, and method of RTP packet transmission and analysis of voice-over-IP communications

A method of providing a quality measure for an output voice signal generated to reproduce an input voice signal, the method comprising: partitioning the input and output signals into frames; for each frame of the input signal, determining a disturbance relative to each of a plurality of frames of the output signal; determining a subset of the determined disturbances comprising one disturbance for each input frame such that a sum of the disturbances in the subset set is a minimum; and using the set of disturbances to provide the measure of quality.

Apparatus and method of providing a quality measure for an output voice signal generated to reproduce an input voice signal

An improved speech processing system has a short-term analyzer, a target vector generator and a maximum likelihood, multi-pulse analyzer. The multi-pulse analyzer generates a plurality of sequences of equal amplitude, variable sign, variably spaced pulses. Each of the sequences have a different amplitude value and each of the pulses within each sequence have equal amplitudes but variable signs. The multi-pulse analyzer generates a signal corresponding to the sequence of equal amplitude, variable sign, variably spaced pulses which, according to maximum likelihood criteria, most closely represents the target vector. The maximum likelihood criteria are based on the cross-correlation of the target vector with an impulse response for the pulses in each sequence and on either a covariance matrix or an autocorrelation vector of the impulse response. In an alternative embodiment, the multi-pulse analyzer generates a plurality of sequences of variable sign trains of equal amplitude, uniformly spaced pulses and performs the analysis on the pulse trains. The pulses within each train have the same sign and each of the sequences of trains of pulses having a different amplitude value.

Speech processing system quantizer of single-gain pulse excitation in

A pitch determination device which separates at least each frame of the input speech signal into separate, lower resolution portions is provided. The pitch determination device includes a resolution lowering unit, a signal selecting unit and a pitch determination device. The resolution lowering unit has an input line on which the input speech signal is provided and K output lines, on each of which output lines, one of K lower resolution input signals is provided. The signal selecting unit has K input lines connected to the K output lines of the resolution lowering unit and has an output line on which is provided one of the K lower resolution signals which fulfill a predetermined quality criterion. The criterion is typically based on the energy content of the lower resolution signals. The pitch determination device has an input line connected to the output line of the signal selecting unit and an output line which provides a pitch value for the selected lower resolution input signal. The lower resolution signals are subsampled by K, where each ith lower resolution signal is offset from said input signal by i sample points, where i varies from 0 to K-1. The pitch determination is performed by cross-correlating or autocorrelating between two low resolution signals, that of the input signal and of a shifted and offset lower resolution signal. For cross-correlation, the shifted lower resolution signal is a previously received signal. For autocorrelation, the shifted lower resolution signal is a shifted version of the low resolution input signal.

Pitch determination using low time resolution input signals

A speech processing system and method are disclosed. In one embodiment of the present invention, the system includes at least a maximum likelihood quantization (MLQ) multi-pulse analysis unit operating on a target vector. The MLQ multi-pulse analyses unit typically determines an initial gain level for the multi-pulse sequence and performs single gain multi-pulse analysis (MPA) a number of times, each with a different gain level. The pulse sequence which most closely represents the target vector is provided as an output signal. In another embodiment, the system includes at least a pulse train multi-pulse analysis unit wherein the target vector is modeled as a series of pulse trains. Each pulse train comprises a plurality of single gain pulses, wherein each pulse is at a position which is a pitch value distance apart from the previous pulse in the pulse train. Combinations of maximum likelihood analyses with pulse trains are also part of the present invention.

Multi-pulse analysis speech processing System and method

A filter utilizes future and past information for at least some of the subframes. Specifically, the filter receives a frame of synthesized speech and, for each subframe of the frame of synthesized speech, produces a signal which is a function of the subframe and of windows of earlier and later synthesized speech. Each window is utilized only when it provides an acceptable match to the subframe.

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Rishon LeZion, Israel

Felix Flomen