摘要 |
A transmitter shifts a baseband data signal having a bandwidth of 2omega<SUB>M </SUB>using a tone signal having a frequency omega<SUB>M</SUB>, which centers a sideband of the data signal at zero frequency. The transmitter then filters the shifted signal to filter out the non-centered sideband, and then adds the tone signal to form a composite signal. The transmitter upconverts the composite signal during a first operational mode using a RF signal having a frequency omega<SUB>C </SUB>equal to a center frequency of a channel. In a second operational mode, the transmitter upconverts a DC level using the same RF signal. The upconverted DC level can be used as a continuous wave carrier signal having a frequency omega<SUB>C</SUB>. The transmitter has a single RF oscillator to output both a SSB signal centered at frequency omega<SUB>C </SUB>during the first mode and a carrier signal of frequency omega<SUB>C </SUB>during the second mode.
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