| 摘要 |
A radio transmitter within a transceiver includes a digital processor and analog circuitry for modulating and transmitting an outgoing digital signal in multiple modes of operation. The digital processor digitally modulates the outgoing digital signal to produce one of a constant envelope modulated digital signal and a variable envelope modulated digital signal based on the particular modulation scheme being used to modulate the outgoing digital signal. In addition, the digital processor filters the outgoing digital signal using filter values selected based on the signal bandwidth of the outgoing digital signal. The analog circuitry converts digital envelope and phase signals of the modulated digital signal to analog envelope and phase signals, and up-converts the analog phase signal from an IF signal to an RF signal, using a loop filter that is programmable based on the signal bandwidth of the outgoing digital signal.
|
