58results about How to "Good echo cancellation" patented technology

The invention provides a robust convex combination type adaptive phone echo canceling method. The method comprises the main steps of A, filtering a far-end signal to obtain quick adaptive filter output y1(n) and low-error filter output y2(n); B, convex combination, namely, performing convex combination for the outputs of the two filters to obtain output y(n) of convex combination filters; c, canceling echo, namely, receiving a near-end signal d(n) with echo by a near-end microphone, subtracting y(n) and then transmitting to a far end as an echo-canceled near-end signal e(n); D, updating tap weight coefficients of the filters; E, updating the weights of the filter, and updating the hybrid parameter a (n) through a formula with sign functions; F, limiting the weight of the filters; G, enabling n to be n+1, and repeating A, B, C, D, E and F until the call is ended. The method is high in convergence rate, low in steady-state error, high in interference resistance, good in echo canceling effect, and maintains good working state under the condition of double-talk of a phone.

The invention discloses a low complexity phone echo self-adaption eliminating method. The method mainly comprises the steps of: A, far-end signal filtration: obtaining a large-step filtering value y1(n) and a small-step filtering value y2(n); B, convex combination: completing the convex combination of the large-step filtering value y1(n) and the small-step filtering value y2(n) so as to obtain a combined filtering value y(n), wherein y(n)=lambda(n)y1(n)+(1-lambda(n))y2(n); C, echo cancellation: completing the subtraction of a near-end signal d(n) which has echo and is picked by a near-end microphone and the combined filtering value y(n), and then sending the signal back to a far end, wherein a return signal is a total residual signal e(n), and e(n)=d(n)-y(n); D, updating the weight coefficient of filtering device taps; E, updating the weight of the filtering device, i.e. updating a hybrid parameter a(n) through a formula which is simplified by a sign function; F, defining the weight of the filtering device; and G, setting n=n+1, and repeating the steps of A, B, C, D, E and F until the conversation is over. The method has strong identification capability to sparse telephone communication systems, and particularly has quick convergence rate and small steady state error in a transition period; an echo eliminating effect is good; and moreover, the method is low in calculation complexity, low in hardware cost and easy to implement.

An improved convex combination decorrelation proportionate self-adaption echo cancellation method comprises the steps that first, far-end signal filtering is carried out, the input vector X(n) of a convex combination self-adaption echo cancellation filter is formed by the discrete value of a far-end signal, and after filtering is carried out on the input vector, a large-step-length filtering value y1(n) and a small-step-length filtering value y2(n) are obtained; second, decorrelation operation is carried out on the input vector X(n), the result of decorrelation operation serves as the weight coefficient updating direction vector Z(n) of the convex combination self-adaption echo cancellation filter; third, convex combination is carried out, the large-step-length filtering value y1(n) and the small-step-length filtering value y2(n) are subjected to convex combination through weight lambda (n), and a combination filter value y(n) is obtained; fourth, echo cancellation is carried out, the combination filter value y(n) is subtracted from a near-end signal d(n) with an echo, and the subtracted near-end signal d(n) is fed back to the far end; fifth, a filter tap weight coefficient is updated; sixth, the weight of the filter is updated; seventh, the weight of the filter is limited; eighth, n is made to be equal to n+1, the first step to the seventh step are repeated till a conversation is over. According to the method, a high rate of convergence can be obtained, the steady state error can be small, and a good anti-jamming capability is achieved.

A voice communication adaptive echo cancellation method based on S-type function, its main steps are: A, echo cancellation B, tap weight vector update: B1, calculate S-type function value, by error signal e (n) and tap weight vector W(n), the calculated S-type function value s(n), B2, the update of the filter tap weight vector, will s(n)‑s 2 (n) Introduce the subtraction term of the adjustment item into the weight vector update formula to obtain the filter tap weight vector W(n+1) at the next moment n+1; C, repeat. The method has fast convergence speed, low steady-state error, strong impact resistance and good echo cancellation effect.

The invention discloses an adaptive echo cancellation method adopting memory proportionate affine projection and based on M-estimation. The adaptive echo cancellation method comprises the following steps: A, a remote signal is sampled; B, in echo estimation, a filter input vector X(n) passes through an adaptive filter and an output value y(n), namely an echo estimation value y(n), is obtained and equal to XT(n)w(n); C, in echo cancellation, a near-end signal d(n) with the echo, acquired by a near-end microphone and the output value y(n) of the adaptive filter are subjected to subtraction operation, and a return signal, namely a residual signal e(n), is returned to a far end and equal to d(n)-y(n); D, in updating of a tap weight vector of the filter, the method adopting memory proportionate affine projection and based on M-estimation is used and the tap weight vector w(n+1) of the adaptive filter at next moment n+1 is calculated and equal to w(n)+mu P(n)(UT(n)P(n)+delta IK)-1 psi [E(n)]; E, n is set to be n+1, and the steps B, C and D are repeated until a call is ended. The method has a good cancellation effect on an acoustic echo of a communication system and is high in convergence speed and small in steady-state error.

A kind of self-adaptive echo cancellation method based on the set member of correlation entropy, its steps are as follows: A, far-end signal acquisition, the far-end signal that far-end transmits is sampled, can obtain the discreteness of the far-end input signal of current moment n Value x(n), whose filter input signal vector is x(n)=[x(n),x(n‑1),...,x(n‑L+1)] T ; B, echo signal estimation, pass the input signal vector x (n) of the current moment n through the adaptive filter, and its output value y (n) is the estimated value of the echo signal; C, echo cancellation, obtain with near-end microphone sampling Subtract the estimated value y(n) of the echo signal from the near-end signal d(n) at the current moment n with echo; D, update the filter tap weight coefficient, and calculate the tap weight vector of the filter at the next moment n+1 w(n+1), w(n+1)=w(n)+μ(n)U(n)(U T (n)U(n)) ‑1 E(n)-C(n); E. Let n=n+1, repeat the above-mentioned process of A, B, C, D, E until the call ends. This method can obtain faster convergence speed and low steady-state error, and the effect of echo cancellation is good.

The invention relates to the field of voice technology, and discloses an adaptive echo cancellation method based on a PC terminal and a mobile terminal. The equipment of the method includes a sending device, a receiving device, and a cloud cancellation server; both the sending device and the receiving device have their own echo cancellation services. Equipment, such as: mobile phone equipment, embedded equipment and PC equipment. The devices that have been processed by the cloud cancellation server do not collect voice data, and the devices that have not been processed will collect voice data. For devices that have problems with the echo cancellation effect when the user uses the device, the echo cancellation parameters will be adaptively adjusted. Through the design of the present invention, the integration of the mainstream echo cancellation technology is realized, the support of cloud services is added, the real intercom environment can be simulated and restored, and the echo cancellation parameters can be dynamically calculated in the cloud, which can well meet the echo requirements of various devices Elimination, to achieve the best effect of echo cancellation.

An adaptive communication echo cancellation method for voice communication, the steps are mainly: A, echo cancellation; B, tap weight vector update: B1, residual signal square sequence E 2 (n) calculation; B2, the calculation of the weighted median residual, to obtain the weighted median residual σ(n) at the current moment n; B3, the calculation of the estimated value of M, to obtain the M of the residual of the current moment n Estimated function value ψ(n); B4, calculation of zero attraction vector, obtains zero attraction factor of tap weight coefficient, thus constitutes zero attraction vector F(n) of current moment n, B5, update of filter tap weight vector, in Introduce the M estimation function value and the zero attraction vector into the update formula to obtain the filter tap weight vector W(n+1) at the next moment n+1; C, repeat. The method has fast convergence speed, low steady-state error and good impact resistance.