发明名称 |
DIGITAL TRANSMITTER SYSTEM AND METHOD |
摘要 |
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 removin g 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 sign al images produced from the DAC can be positioned in the desired frequency band(s). Fo r example, the digital transmitter can position the digital signals within non - overlapping portions of a conversion bandwidth defined as one-half the conversion rate f or the DAC. When the digital signals are converted into analog form, the DAC produc es 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.
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申请公布号 |
CA2369227(C) |
申请公布日期 |
2005.03.29 |
申请号 |
CA20022369227 |
申请日期 |
2002.01.23 |
申请人 |
LUCENT TECHNOLOGIES INC. |
发明人 |
GARCERAN, JULIO ANTONIO;KAMINSKI, WALTER JOSEPH;KOLSRUD, ARILD |
分类号 |
H03C1/00;H04B1/04;(IPC1-7):H04L27/00;H03M1/66 |
主分类号 |
H03C1/00 |
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