Kumu Networks Patent applications |
Patent application number | Title | Published |
20140219139 | SIGNAL CANCELLATION USING FEEDFORWARD AND FEEDBACK PATHS - A circuit that cancels a self-interference signal includes, in part, a pair of signal paths that are substantially in phase, each of which paths includes a passive coupler, a delay element and a variable attenuator. The circuit further includes, in part, a first group of P signal paths each of which is substantially in phase with the pair of paths, a second group of M signal paths each of which is substantially out-of-phase relative to the pair of signal paths, and at least a pair of feedback paths. Each of the P and M signal paths, as well as the feedback paths includes a delay element and a variable attenuator. Optionally, each of the M signal paths is optionally 180° out-of-phase relative to the pair of signal paths. | 08-07-2014 |
20140204808 | TUNING ALGORITHM FOR MULTI-TAP SIGNAL CANCELLATION CIRCUIT - A self-interference signal cancellation circuit includes a transmitter for transmitting a transmit signal, a plurality of signal paths, a controller, and a receiver for receiving a signal. Each signal path includes a delay element and a variable attenuator having attenuation levels set by the controller. A combiner generates an output signal by combining outputs of the signal paths. The circuit computes a matrix based on first and second output signals associated with first and second attenuation levels. The controller concurrently varies the attenuation level of each signal path so that a product of the matrix and the attenuation levels of the signal paths is substantially equal to the received signal. The circuit may iteratively compute the matrix using different transmit signal frequencies or with an FFT. The controller iteratively varies the attenuation level of the attenuators until a sum of the product and the received signal satisfies a predefined condition. | 07-24-2014 |
20140169236 | FEED FORWARD SIGNAL CANCELLATION - A circuit that cancels a self-interference signal includes, in part, a pair of signal paths that are substantially in phase, each of which paths includes a passive coupler, a delay element and a variable attenuator. The circuit further includes, in part, a first group of P signal paths each of which is substantially in phase with the pair of paths, and a second group of M signal paths each of which is substantially out-of-phase relative to the pair of signal paths. Each of the P and M signal paths includes a delay element and a variable attenuator. Furthermore, (P−1) signal paths of the first group of P signal paths, and (M−1) signal paths of the second group of M signal paths include a passive coupler. Optionally, each of the M signal paths is optionally 180° out-of-phase relative to the pair of signal paths. | 06-19-2014 |