Arbitrary noise shaping transmitter with receive band notches

Patent metadata

Field	Value
Publication number	US-10044367-B1
Application number	US-201715671888-A
Country	US
Kind code	B1
Filing date	Aug 8, 2017
Priority date	Aug 8, 2017
Publication date	Aug 7, 2018
Grant date	Aug 7, 2018

Abstract

Techniques for generating signals with arbitrary noise shaping are discussed. One example apparatus configured to be employed within a transmitter can comprise a noise shaper configured to: receive an input signal x q ; and apply noise shaping to the input signal x q to generate a noise shaped output signal y q , wherein an in-band noise of the noise shaped output signal y q is below an in-band noise threshold of a spectral mask associated with the noise shaper, wherein an out-of-band noise of the noise shaped output signal y q is below an out-of-band noise threshold of the spectral mask, and wherein a noise of the output signal y q in each of a plurality of bandpass regions is below an associated noise threshold for that bandpass region of the spectral mask.

First claim

What is claimed is:

1. An apparatus configured to be employed within a transmitter, comprising:
a noise shaper configured to:
receive an input signal x q ; and
apply noise shaping to the input signal x q to generate a noise shaped output signal y q , wherein an in-band noise of the noise shaped output signal y q is below an in-band noise threshold of a spectral mask associated with the noise shaper, wherein an out-of-band noise of the noise shaped output signal y q is below an out-of-band noise threshold of the spectral mask, and wherein a noise of the output signal y q in each of a plurality of bandpass regions is below an associated noise threshold for that bandpass region of the spectral mask.

2. The apparatus of claim 1 , wherein the noise shaper is configured to compensate for DAC (Digital-to-Analog Converter) nonlinearities in the input signal x q .

3. The apparatus of claim 1 , wherein the noise shaper is further configured to employ delta-sigma modulation to apply noise shaping to the input signal x q .

4. The apparatus of claim 1 , wherein the noise shaper is further configured to employ pyramid encoding to apply noise shaping to the input signal x q .

5. The apparatus of claim 4 , wherein the noise shaper comprises:
a pyramid encoder configured to receive a signal e q comprising the B p LSB (least significant bits) of the input signal x q and to generate a B p bit noise-shaped signal p q based on the signal e q and a plurality of filter taps of the pyramid encoder; and
an adder configured to add the B p bit noise-shaped signal p q to a B c bit signal c q comprising the B c MSB (most significant bits) of the transmit signal to generate a combined signal c q +p q ,
wherein the noise shaper is configured to generate the noise shaped output signal y q based on the combined signal c q +p q .

6. The apparatus of claim 5 , wherein the noise shaper further comprises saturation circuitry configured to apply saturation arithmetic to the combined signal c q +p q to generate the noise shaped output signal y q .

7. The apparatus of claim 5 , wherein the B p bit noise-shaped signal p q and the B c bit signal c q overlap by at least one bit.

8. The apparatus of claim 1 , wherein the out-of-band noise for at least a portion of an out-of-band region of the noise shaped output signal y q is above the associated noise threshold for each bandpass region of the spectral mask.

9. The apparatus of claim 1 , wherein the noise shaper is configured to apply noise shaping to the input signal x q via a plurality of filter taps.

10. The apparatus of claim 9 , wherein the noise shaper is configured to generate the filter taps based on a look-up table of pre-computed values for the plurality of filter taps.

11. The apparatus of claim 9 , wherein the noise shaper is configured to generate the filter taps based on a M-level quantizer, wherein M is greater than or equal to 3.

12. An apparatus configured to be employed within a transmitter, comprising:
a quantizer configured to receive a signal x q and to generate a B c bit signal c q , wherein B c is a positive integer;
a first adder configured to subtract the B c bit signal c q from the signal x q to generate a difference signal e q ;
a noise shaper configured to receive the difference signal e q and to generate a noise-shaped B p bit signal p q , wherein B p is a positive number less than B c ;
a second adder configured to combine the B c bit signal c q and the noise-shaped B p bit signal p q to generate a noise shaped B y bit signal c q +p q , wherein B y is a positive integer greater than B c ; and
saturation circuitry configured to receive the noise shaped B y B bit signal c q +p q and to generate a saturated noise shaped B y bit signal y q .

13. The apparatus of claim 12 , further comprising a DAC (Digital-to-Analog Converter) model configured to compensate for DAC nonlinearities in the input signal x q .

14. The apparatus of claim 12 , wherein the noise shaper is further configured to employ delta-sigma modulation to apply noise shaping to the input signal x q .

15. The apparatus of claim 12 , wherein the noise shaper is further configured to employ pyramid encoding to apply noise shaping to the input signal x q .

16. A non-transitory machine readable medium comprising instructions that, when executed, cause a transmitter to:
receive an input signal x q ; and
apply noise shaping to the input signal x q to generate a noise shaped output signal y q , wherein an in-band noise of the noise shaped output signal y q is below an in-band noise threshold of a spectral mask associated with the noise shaper, wherein an out-of-band noise of the noise shaped output signal y q is below an out-of-band noise threshold of the spectral mask, and wherein a noise of the output signal y q in each of a plurality of bandpass regions is below an associated noise threshold for that bandpass region of the spectral mask.

17. The machine readable medium of claim 16 , wherein the instructions, when executed, further cause the transmitter to compensate for DAC (Digital-to-Analog Converter) nonlinearities in the input signal x q .

18. The machine readable medium of claim 16 , wherein the instructions, when executed, further cause the transmitter to employ delta-sigma modulation to apply noise shaping to the input signal x q .

19. The machine readable medium of claim 16 , wherein the instructions, when executed, further cause the transmitter to employ pyramid encoding to apply noise shaping to the input signal x q .

Assignees

• Intel Corp

Inventors

• Azadet Kameran
• Sanchez Ramon

Classifications

• H03M7/304

  with distributed feedback, i.e. with feedback paths from the quantiser output to more than one filter stage · CPC title

• H03M1/007

  among different resolutions · CPC title

• H03L7/20

  using a harmonic phase-locked loop, i.e. a loop which can be locked to one of a number of harmonically related frequencies applied to it (H03L7/22 takes precedence) · CPC title

• H03M3/33 Primary

  the dither being a random signal · CPC title

• H03M3/436

  characterised by the order of the loop filter, e.g. error feedback type · CPC title