105results about How to "Reduce echo" patented technology

A speech signal processing system combines acoustic noise reduction and echo cancellation to enhance acoustic performance. The speech signal processing system may be used in vehicles or other environments where noise-suppressed communication is desirable. The system includes an adaptive beamforming signal processing unit, an adaptive echo compensating unit to reduce acoustic echoes, and an adaptation unit to combine noise reduction and adaptive echo compensating.

The present invention comprises a method for audio / video conferencing. In a preferred embodiment, the method comprises using a dynamic threshold value to determine whether there is speech on a line. One aspect, the method comprises determining a dynamic threshold value based on one or more characteristics of signals received on a port, associating that dynamic threshold value with the port; and comparing one or more characteristics of signals subsequently received on the port to the dynamic threshold value. Signals received over a plurality of ports are summed, but for ports whose signal characteristics have a specified relationship to the dynamic threshold value associated with that port, signals are not contained in the sum.

A speech signal processing system combines acoustic noise reduction and echo cancellation to enhance acoustic performance. The speech signal processing system may be used in vehicles or other environments where noise-suppressed communication is desirable. The system includes an adaptive beamforming signal processing unit, an adaptive echo compensating unit to reduce acoustic echoes, and an adaptation unit to combine noise reduction and adaptive echo compensating.

The invention provides a wing with changeable trailing edge camber driven by a shape memory spring, relating to a wing with a changeable trailing edge camber, and aiming at the problems of traditional airplanes that a mechanism is complex and heavy, airflow breakaway is quite early and aerodynamic efficiency is low. The front end face and the back end face of an upper metal plate are fixedly connected with the front end faces of a connecting plate and the trailing edge; the front end face and the back end face of the lower metal plate are fixedly connected with the front end face of the connecting plate and the trailing edge; the same side surface of the upper metal plate and the lower metal plate are fixed with an upper prop stay and a lower prop stay; the two ends of a first shape memory spring are fixedly connected with a fixed plate and the upper metal plate; the two ends of a second shape memory spring are fixedly connected with the front end faces of the upper prop stay and the trailing edge; the two ends of a third shape memory spring are fixedly connected with the fixed plate and the lower metal plate; and the two ends of a fourth shape memory spring are fixedly connected with the front end faces of the lower prop stay and the trailing edge. The invention has the advantages of light weight, simple structure and high aerodynamic efficiency.

An echo cancellation technique that can process multi-input microphone signals with only a small increase in the overall CPU consumption compared to implementing the algorithm for a single channel microphone signal. Furthermore, the invention provides an architecture that provides for echo cancellation for multiple applications in parallel with only a small increase in CPU consumption compared to a single instance of echo cancellation with a single microphone input and multi-output channel playback.

A separation circuit, method of determining a residual level of an echo, and an echo canceling system, bit pump and transceiver employing the circuit and method. The echo canceling system employing the separation circuit is couplable between a transmit and receive path of the bit pump and generates an echo canceling signal. In one embodiment, the separation circuit includes a symbol determination circuit that accepts a receive signal, propagating along the receive path, substantially free of an echo and determines a symbol associated with the receive signal. The separation circuit also includes an estimator stage, coupled to the symbol determination circuit, that receives the symbol and provides an estimated receive signal. The separation circuit generates data representing a residual level of the echo as a function of the estimated receive signal and the echo canceling signal.

The invention discloses an explosion experimental device for simulating an underground free field environment. The device comprises a spherical pressure container, an inner wall sprayed layer, an operation sealing head, a detonation line interface, a pressure sensor test interface, an explosive fixing rod, a fixing groove, a water inlet, a water outlet, an installation base, a flange plate, toughened glass and a base support. The explosion experimental device has the beneficial effects that the spherical pressure container is used as a main body, meeting the requirement of certain amount of explosive for many experiments; the device can be pressurized so as to simulate a certain deep water environment; a spherical tank is provided with an observation window which allows an operator to observe shapes of bubbles in the tank in experiment; the interior of the tank is treated by spraying or pasting multiple layers of material better in wave impedance matching, so as to absorb or suppress reflected impulse load to realize an underground free field environment.

The invention provides a complex-hinge transformable trailing edge mechanism based on planar linkage closed-loop units. The complex-hinge transformable trailing edge mechanism comprises at least three closed-loop linkage units and a drive mechanism. Each closed-loop linkage unit is a planar linkage structure based on a 6R closed-loop unit and has one freedom degree. The closed-loop linkage units include a tail-end unit, at least one middle unit and a starting-end unit which are parallelly arranged, and the middle units are arranged between the starting-end unit and the tail-end unit. Compared with the prior art, the complex-hinge transformable trailing edge mechanism has the advantages that the basic units of the complex-hinge transformable trailing edge mechanism are independent 6R closed-loop units, the units influence on another, and the output of the previous unit is the input of the next unit; the whole mechanism contains few linkages and is lightweight; the freedom degree of the whole mechanism is 1, the mechanism can be driven by only one drive motor, the weight of the mechanism is reduced, system control difficulty is lowered, and the gradual bending effect of a transformable wing is good due to the fact that multiple basic unit modules are used.

An echo canceler includes an recursive least squares lattice to whiten a far-end signal s1(t) and provide whitened time delays. The echo canceler further decorrelates a microphone signal based on the whitened time delays to reduce echoes of the far-end signal s1(t) that are contained in the microphone signal x2(t). The echo canceler does not use a double-talk detector and avoids all problems inherent with their use. Thus, speaker phones, and other communication devices, can continuously operate in full-duplex mode of operation thereby providing natural conversational hands-free communication.

A packet voice transceiver adapted to reside at a first end of a communication network and to send an ingress communication signal comprising voice packets to, and receive an egress communication signal comprising voice packets from, a second packet voice transceiver residing at a second end of the communication network. The packet voice transceiver includes a far-end echo canceller that reduces echo that is present in the egress communication signal. The far-end communicates with other functional components of the transceiver system and adapts its behavior based on the activity of the other functional components.

An echo canceler includes an adaptable filter that is updated during double-talk and far-end talk. The echo canceler receives a microphone signal that includes a near-end signal and echoes resulting from a far-end signal. The echo canceler whitens the far-end signal and decorrelates the microphone signal. The whitening and decorrelating is done as a preprocessing step for the one-unit blind source separation algorithm. A criterion of measure is used to emphasize the statistical independence of the echo canceled signal and the far-end signal. The echo cancellation problem is cast as a one-unit blind source separation problem. A one-unit blind source separation algorithm such as negentropy maximization can be used to extract the echo canceled signal.

The invention discloses a recording method, a terminal and a computer readable storage medium, and the method comprises the steps: obtaining a recording scene after obtaining a recording instruction;when the located recording scene is a call recording scene, entering a call recording mode; when the located recording scene is a recording playing scene, entering a recording playing mode; and when the located recording scene is a local recording scene, entering a local playing recording mode. The recording method, the terminal and the computer readable storage medium aim to solve technical problems that existing recording equipment cannot be suitable for various recording scenes, and the recording effect is poor. According to the method and the device, the targeted recording modes are designed for different recording scenes, the voice can be differentially recorded based on the characteristics of the recording scenes, the definition and the intelligibility of the voice are improved, incoherent noise and echoes are weakened, and in addition, a basis can be provided for subsequent voice-to-character conversion.

The invention discloses a radar / infrared compatible stealth metasurface, which belongs to the technical field of novel artificial electromagnetic materials. The metasurface comprises a conductive reflection layer, a dielectric layer and a conductor film functional layer which are sequentially arranged from bottom to top; the conductor film functional layer is of an M * M array structure of patch large units I and patch large units II; each patch large unit I is of an n1 * n1 array structure composed of patch small units I, and each patch large unit II is of an n2 * n2 array structure composedof patch small units II; M is an even number; the patch large units I and the patch large units II are the same in size and number; the patch small units I and the patch small units II are different in size. The metasurface is composed of a conductive reflection layer-dielectric layer-conductor film functional layer sandwich structure, the structure is simple, and radar and infrared stealth compatibility of the structure can be achieved at the same time only through one layer of artificial structure unit array.