Methods and apparatus for carrier suppression in a radio modulator
US6058291A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 3, 1997 |
| Grant date | May 2, 2000 |
| Priority date | — |
| Expiry date | Dec 3, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2027/0018
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
Methods and apparatus for dynamically calibrating a modulator in a radio transmitter are provided. In a preferred embodiment an In-Phase and Quadrature (I/Q) modulator in a radio modem is calibrated by means of a modulator, a digital signal processor and a power sensor. The modulator being electrically adapted to receive a local oscillator input having a carrier frequency and a substantially direct current (DC) input having an amplitude in order to produce an output having a power magnitude at the carrier frequency in a frequency defined power spectrum. The power sensor being in electrically succession to the modulator to measure the power magnitude of the output to permit the digital signal processor (DSP), electrically between the modulator and the power sensor, to compare the measured power magnitude with a minimum threshold power magnitude to determine which is greater. If the power magnitude is greater, the DSP reiteratively alters the amplitude of the DC input until the measured power magnitude of the output is less than the minimum threshold power magnitude. The minimum threshold power magnitude is preferably stored in the digital signal processor and defines a suitable powe…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.