Device and method for detection and reduction of intermodulation distortion
US6009129A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 28, 1997 |
| Grant date | Dec 28, 1999 |
| Priority date | — |
| Expiry date | Feb 28, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/1027
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
In the front end of a CDMA cellular or broadband PCS mobile phone receiver, a switched bypass connection is provided to bypass the low noise amplifier, sending the received signal through an amplifier bypass connection. The amplifier bypass connection may include an attenuator. The switched bypass is activated by a control signal generated by a digital signal processor. The digital signal processor analyzes the received signal to detect and determine the relative contribution of the IMD interference to the total received signal power and, when the IMD interference exceeds a predetermined level, sends a control signal to bypass the low noise amplifier. Identification of the presence of IMD interference is by spectral estimation to discern when the mobile phone is in the presence of large near-band signals from an AMPS or other narrow-band base station which causes in-band IMD. In a preferred embodiment, the spectral estimation is performed by collecting a series of data samples from the received signal and, using a digital signal processor (DSP), computing a Discrete Fourier Transform (DFT) to generate frequency domain data, passing the data through a filter bank, then using a decis…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.