Digital transmitter and method
First Claim
1. A transmitter, comprising:
- a digital upconverter for receiving a baseband digital signal having a first rate and upconverting the baseband digital signal to an upconverted digital signal having a second rate;
circuitry for receiving the upconverted digital signal and separating the upconverted digital signal to generate a plurality of parallel digital signals;
a modulator for receiving and modulating the parallel digital signals to generate a plurality of modulated digital signals;
a digital-to-digital modulator for receiving the plurality of modulated digital signals and generating a plurality of modulated digital signals; and
a multiplexer operable to generate a digital output signal.
4 Assignments
0 Petitions
Accused Products
Abstract
A transmitter and method is provided for digitally upconverting a baseband digital signal to a modulated intermediate frequency (IF) digital signal and sigma-delta modulating the IF digital signal. The baseband digital signal is split into N phases, as can be accomplished using a polyphase interpolation technique (polyphase filter), and modulated. The modulated N phases are not recombined and each phase is further modulated, as can be accomplished using a digital-to-digital sigma-delta modulator that generates digital output signals at the same rate. A high speed digital multiplexer multiplexes the digital output signals into a single bit stream at a higher rate for subsequent power amplification and RF transmission.
-
Citations
23 Claims
-
1. A transmitter, comprising:
-
a digital upconverter for receiving a baseband digital signal having a first rate and upconverting the baseband digital signal to an upconverted digital signal having a second rate;
circuitry for receiving the upconverted digital signal and separating the upconverted digital signal to generate a plurality of parallel digital signals;
a modulator for receiving and modulating the parallel digital signals to generate a plurality of modulated digital signals;
a digital-to-digital modulator for receiving the plurality of modulated digital signals and generating a plurality of modulated digital signals; and
a multiplexer operable to generate a digital output signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
-
-
14. A transmitter, comprising:
-
means for receiving a baseband digital signal having a first rate and upconverting the baseband digital signal to an upconverted digital signal having a second rate;
means for receiving the upconverted digital signal and separating the upconverted digital signal to generate a plurality of parallel digital signals;
means for receiving and modulating the parallel digital signals to generate a plurality of modulated digital signals;
means for receiving the plurality of modulated digital signals and generating a plurality of second modulated digital signals; and
means for receiving and multiplexing the plurality of second modulated digital signals to generate a digital output signal. - View Dependent Claims (15, 16)
-
-
17. A method of upconverting a digital signal for RF transmission, comprising:
-
receiving a baseband digital signal having a first rate;
upconverting the baseband digital signal to an upconverted digital signal having a second rate;
separating the upconverted digital signal into a plurality of phased digital signals;
modulating the phased digital signals to generate a plurality of modulated digital signals;
modulating the plurality of modulated digital signals to generate a plurality of second modulated digital signals; and
multiplexing the plurality of second modulated digital signals and to generate and output a digital output. - View Dependent Claims (18, 19, 20)
-
-
21. A wireless communications device, comprising:
a transmitter, comprising, a digital upconverter for receiving a baseband digital signal having a first rate and upconverting the baseband digital signal to an upconverted digital signal having a second rate, circuitry for receiving the upconverted digital signal and separating the upconverted digital signal to generate a plurality of parallel digital signals, a modulator for receiving and modulating the parallel digital signals to generate a plurality of modulated digital signals, a digital-to-digital modulator for receiving the plurality of modulated digital signals and generating a plurality of modulated digital signals, and a multiplexer operable to generate a digital output signal. - View Dependent Claims (22, 23)
Specification