Walter Kaminski

US Patent:

6944238, Sep 13, 2005

Filed:

Feb 16, 2001

Appl. No.:

09/784846

Inventors:

Julio Antonio Garceran - Randolph NJ, US
Walter Joseph Kaminski - Long Valley NJ, US
Arild Kolsrud - Bridgewater NJ, US

Assignee:

Lucent Technologies Inc. - Murray Hill NJ

International Classification:

H04L027/20
H04K001/02

US Classification:

375295, 375297, 375146

Abstract:

A digital transmitter converts a digital signal into analog form with a digital to analog converter (DAC) and uses an analog signal image produced from the DAC to provide an analog signal at a transmission frequency and/or uses a projected analog signal image to produce analog signals for transmission. Rather than removing analog signal images with a low pass filter at the output of the DAC and/or using analog signal images and analog mixers for frequency conversion, the digital transmitter uses the analog signal images from the DAC to produce the analog signals at the desired frequency/frequencies. By setting and/or adjusting the conversion rate for the DAC and/or the digital signal frequency/frequencies, the analog signal images produced from the DAC can be positioned in the desired frequency band(s). For example, the digital transmitter can position the digital signals within non-overlapping portions of a conversion bandwidth defined as one-half the conversion rate for the DAC. When the digital signals are converted into analog form, the DAC produces analog signal images periodically repeated at multiples of one-half the conversion rate such that analog signal images are produced at the appropriate frequency band(s) for amplification and transmission.