초록 ▼

A known cross-coupled adaptive noise cancelling arrangement uses an adaptive noise filter and an adaptive cross-talk filter in a feedback loop for cancelling correlated noise at a primary signal input and reference input. This known cross-coupled ANC does not operate satisfactorily, particularly not

A known cross-coupled adaptive noise cancelling arrangement uses an adaptive noise filter and an adaptive cross-talk filter in a feedback loop for cancelling correlated noise at a primary signal input and reference input. This known cross-coupled ANC does not operate satisfactorily, particularly not for acoustic noise cancellation. This leads to reverberant-like sound signals, in particular in a typical office room with remote noise sources. A different configuration of a cross-coupled adaptive noise cancelling arrangement gives rise to a better performance. The adaptive cross-talk filter is now split into a pre-filter section and an adaptive filter section, the sections using different input signals. The pre-filter section estimates the desired signal from the input signal of the noise cancelling arrangement, and the adaptive filter section has its input coupled to the output of the noise cancelling arrangement, a delay section being provided between the input and the output of the noise cancelling arrangement. In an embodiment, the pre-filter section and the adaptive filter section are separate filters.

대표청구항 ▼

[ We claim:] [1.] An adaptive noise cancelling arrangement for cancelling noise in a noise disturbed signal, said adaptive noise cancelling arrangement comprising:a primary signal input for receiving a primary signal which is disturbed with noise;at least one reference signal input;a signal output f

[ We claim:] [1.] An adaptive noise cancelling arrangement for cancelling noise in a noise disturbed signal, said adaptive noise cancelling arrangement comprising:a primary signal input for receiving a primary signal which is disturbed with noise;at least one reference signal input;a signal output for providing a noise cancelled signal;a first subtracter having a first input coupled to the reference signal input;an adaptive noise filter having an input coupled to to an output of the first subtracter;a second subtracter having a first input coupled to an output of the adaptive noise filter, a second input coupled to the primary signal input, and an output coupled to the signal output; andan adaptive cross-talk filter having an input coupled to the signal output, and an output coupled to a second input of the first subtracter, characterised in that the adaptive cross-talk filter comprises a pre-filter section for pre-filtering the primary signal, and an adaptive filter section for determining coefficients of the pre-filter section, an input of the pre-filter section being coupled to the primary signal input, and an input of the adaptive filter section being coupled to the signal output, the adaptive noise cancelling arrangement further comprising a first delay section and second delay section, the first delay section being coupled between the primary signal input and the second input of the second subtracter, and the second delay section being coupled between the input of the adaptive noise filter and a further input of the adaptive cross-talk filter.