Patent · US Expired

Compensated .DELTA..SIGMA. controlled phase locked loop modulator

US6011815A · kind A · utility

21Cited by

13References

17Claims

0Family size

Assignee

Telefonaktiebolaget LM Ericsson (Publ) · SE

Inventors

Håkan Eriksson · Täby, SE
Kjell Gustafsson · Lund, SE
Bjorn Lindquist · Bjärred, SE

Key dates

Filing date	Sep 16, 1997
Grant date	Jan 4, 2000
Priority date	—
Expiry date	Sep 16, 2017

Classification

Technology area (CPC H)Electricity
CPC primaryH03L7/1976
WIPO fieldBasic communication processes
WIPO sectorElectrical engineering

Abstract

A .DELTA..SIGMA. controlled phase locked loop modulation is used with limited oversampling factors while fulfilling the spectrum and/or phase noise requirements on the modulation in the phase locked loop. By filtering the quantization noise sufficiently then compensating for the distortion of the modulation at the input of the .DELTA..SIGMA. modulator, the required oversampling factor of the .DELTA..SIGMA. controlled phase locked loop modulators can be reduced without loss of performance. The distortion is mitigated by performing a compensation at the input to the .DELTA..SIGMA. modulator. The noise reduction obtained by lowering the bandwidth of the phase locked loop can then be traded to reduce the oversampling factor.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.