LMS adaptive filter for digital cancellation of second order inter-modulation due to transmitter leakage
US8855029B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 17, 2010 |
| Grant date | Oct 7, 2014 |
| Priority date | — |
| Expiry date | Jun 22, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/03878
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A transmit signal second-order inter-modulation (IM2) canceller for a portable handset using a full duplex mode of operation (e.g., WCDMA) is used to controllably reduce IM2 introduced by a transmit signal that appears in a received signal in a receive channel of the portable handset. The transmit signal IM2 canceller includes a delay estimator and a digital signal adjuster. The delay estimator receives a first input from a receive channel and a second input from a transmit channel. The delay estimator generates an estimate of the IM2 that the transmit channel introduces in the receive channel. The digital signal adjuster removes the estimate of the IM2 before forwarding a modified receive channel signal to a baseband subsystem of the portable handset.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.