A digital filter structure and related method of digital filtering are presented. The digital filter structure is arranged to receive one or more clocked input signals having a first clock rate, and which is driven at a second clock rate higher than said first clock rate. The digital filter structure has a plurality of delay elements and multiplexing circuitry arranged to selectively engage the delay elements such that, at every clock cycle of the digital filter structure, a filter operation is performed on a different stream of data. The disclosure can be applied in many different contexts. One particular implementation example is that of an adaptive noise cancellation (ANC) system using sigma-delta infinite impulse response filters. In this context the present disclosure minimizes latency and hardware implementation area by requiring only one filtering circuit for multiple channels of data to be filtered.

The present application relates to an adaptive filter using manageable resource sharing and a method of operating the adaptive filter. The adaptive filter comprises a cluster controller configured for allocating each of several computational blocks to one of several clusters and a routing controller for configuring the routing of tapped delay signals by a routing logic to the respective cluster in accordance with an allocation of the tapped delay signals to the clusters. Each of computational blocks is configured for adjusting one filter coefficient, c.sub.i(n), in one cycle of an iterative procedure according to an adaptive convergence algorithm. The number of computational blocks is less than an order of the adaptive filter.

The present application relates to an adaptive filter using resource sharing and a method of operating the adaptive filter. The filter comprises at least one computational block, a monitoring block and an offset calculation block. The computational block is configured for adjusting a filter coefficient, c.sub.i(n), in an iterative procedure according to an adaptive convergence algorithm. The monitoring block is configured for monitoring the development of the determined filter coefficient, c.sub.i(n), during the performing of the iterative procedure. The offset calculation block is configured for determining an offset, Off.sub.i, based on a monitored change of the filter coefficient, c.sub.i(n), each first time period, T.sub.1, and for outputting the determined offset, Off.sub.i, to the computational block if the determined filter coefficient, c.sub.i(n), has not reached the steady state. The computational block is configured to accept the determined offset, Off.sub.i, and to inject the determined offset, Off.sub.i, into the iterative procedure.

The present application relates to an adaptive filter using manageable resource sharing and a method of operating the adaptive filter. The adaptive filter comprises a cluster controller configured for allocating each of several computational blocks to one of several clusters and a routing controller for configuring the routing of tapped delay signals by a routing logic to the respective cluster in accordance with an allocation of the tapped delay signals to the clusters. Each of computational blocks is configured for adjusting one filter coefficient, c.sub.i(n), in one cycle of an iterative procedure according to an adaptive convergence algorithm. The number of computational blocks is less than an order of the adaptive filter.

The present application relates to an adaptive filter using resource sharing and a method of operating the adaptive filter. The filter comprises at least one computational block, a monitoring block and an offset calculation block. The computational block is configured for adjusting a filter coefficient, c.sub.i(n), in an iterative procedure according to an adaptive convergence algorithm. The monitoring block is configured for monitoring the development of the determined filter coefficient, c.sub.i(n), during the performing of the iterative procedure. The offset calculation block is configured for determining an offset, Off.sub.i, based on a monitored change of the filter coefficient, c.sub.i(n), each first time period, T.sub.1, and for outputting the determined offset, Off.sub.i, to the computational block if the determined filter coefficient, c.sub.i(n), has not reached the steady state. The computational block is configured to accept the determined offset, Off.sub.i, and to inject the determined offset, Off.sub.i, into the iterative procedure.