Methods and system of a digital transmitter with reduced quantization noise

Patent metadata

Field	Value
Publication number	US-10128875-B1
Application number	US-201815941054-A
Country	US
Kind code	B1
Filing date	Mar 30, 2018
Priority date	Mar 30, 2018
Publication date	Nov 13, 2018
Grant date	Nov 13, 2018

Abstract

A digital transmitter includes baseband interfaces to generate digital baseband signals with baseband frequencies, digital-upconverting stages to upconvert the baseband frequencies to first radio frequencies having a predetermined frequency range, a M-Band ΔΣM modulator to modulate the up-stage signals based on noise shaping and noise quantization processes, delay registers to align phases of the modulated up-stage signals, a noise canceler to generate noise canceling signals with a converted polarity, a Switch Mode Power Amplifier to amplify the phase aligned modulated up-stage signals up to a predetermined power level, a linear power amplifier to amplify the noise canceling signals up to the predetermined power level, a power combiner to combine to generate transmitting signals by combining the amplified phase aligned modulated up-stage signals and the amplified noise canceling signals, and an antenna to transmit the transmitting signals.

First claim

We claim:

1. A noise canceler for reducing quantization noises of transmitting signals, comprising:
a comparator having first and second input ports, wherein the first input port receives an input signal of a first quantizer and the second input port receives an output signal of the first quantizer, wherein the input and output signals of the first quantizer are subtracted to extract a noise component of the input signal of the first quantizer;
a noise transfer function (NTF) block to apply a noise transfer function to the noise component of the input signal to generate an NTF noise signal;
a polarity convertor to reverse a polarity of the NTF noise signal into an opposite polarity; and
a second quantizer to generate an N-bit quantization noise signal by quantizing the converted NTF noise signal by N bits, wherein N is a natural number.

2. The noise canceler of claim 1 , wherein the N is equal to or greater than 2.

3. The noise canceler of claim 1 , wherein the first quantizer is disposed outside the canceler.

4. The noise canceler of claim 1 , wherein the first quantizer is included in a Delta-Sigma Modulator disposed outside the canceler.

5. The noise canceler of claim 1 , wherein an output of the second quantizer is connected to a linear power amplifier (PA).

6. The noise canceler of claim 1 , wherein the N-bit quantizer generates one of uniform and non-uniform distribution levels.

7. The noise canceler of claim 6 , wherein the distribution levels are chosen so as to reduce a number of bits.

8. The noise canceler of claim 1 , wherein the polarity converter is arranged after the second quantizer, wherein the second quantizer is arranged after the NTF block.

9. A digital transmitter comprising:
baseband interfaces to generate digital baseband signals with baseband frequencies;
digital-upconverting stages to upconvert the baseband frequencies to first radio frequencies (RFs) having a predetermined frequency range;
a M-Band ΔΣ modulator to modulate the up-stage signals based on noise shaping and noise quantization processes;
delay registers to align phases of the modulated up-stage signals;
a noise canceler of claim 1 to generate noise canceling signals with a converted polarity;
a Switch Mode Power Amplifier (SMPA) to amplify the phase aligned modulated up-stage signals up to a predetermined power level;
a linear power amplifier (linear PA) to amplify the noise canceling signals up to the predetermined power level;
a power combiner to combine to generate transmitting signals by combining the amplified phase aligned modulated up-stage signals and the amplified noise canceling signals; and
an antenna to transmit the transmitting signals.

10. The digital transmitter of claim 9 , wherein the N is equal to or greater than 2.

11. The digital transmitter of claim 9 , wherein the first quantizer is disposed outside the canceler.

12. The digital transmitter of claim 9 , wherein the first quantizer is included in a Delta-Sigma Modulator disposed outside the canceler.

13. The digital transmitter of claim 9 , wherein an output of the second quantizer is connected to a linear power amplifier (PA).

14. The digital transmitter of claim 9 , wherein the N-bit quantizer generates one of uniform and non-uniform distribution levels.

15. The digital transmitter of claim 14 , wherein the distribution levels are chosen so as to reduce a number of bits.

16. The digital transmitter of claim 9 , wherein the polarity converter is arranged after the second quantizer, wherein the second quantizer is arranged after the NTF block.

17. The digital transmitter of claim 9 , wherein the power combiner is integrated in the SMPA.

18. The digital transmitter of claim 9 , wherein the power combiner is integrated in the antenna.

Assignees

• Mitsubishi Electric Res Laboratories Inc

Inventors

• Ma Rui
• Da Costa Dinis Daniel Antonio

Classifications

• H04B1/0475 Primary

  with means for limiting noise, interference or distortion (H04B1/0483 takes precedence) · CPC title

• H03M3/472

  Shared, i.e. using a single converter for multiple channels · CPC title

• H03F3/217

  Class D power amplifiers; Switching amplifiers · CPC title

• H03M3/402

  Arrangements specific to bandpass modulators · CPC title

• H03F3/211

  using a combination of several amplifiers (H03F3/60 takes precedence) · CPC title