Techniques and methods for aliasing digital beamformers for reduced computational loads

Patent metadata

Field	Value
Publication number	US-9628162-B1
Application number	US-201615271958-A
Country	US
Kind code	B1
Filing date	Sep 21, 2016
Priority date	Sep 21, 2016
Publication date	Apr 18, 2017
Grant date	Apr 18, 2017

Abstract

A phased array receiver for use with a first received analog signal and a second received analog signal, the phased array receiver including: a first analog to digital converter to generate a first received digital signal; a second analog to digital converter to generate a second received digital signal; a first down-sampler to generate a first down-sampled digital signal; a second down-sampler to generate a second down-sampled digital signal; a first polyphase low pass filter to generate a first filtered down-sampled received digital signal; a second polyphase low pass filter to generate a second filtered down-sampled received digital signal; and a beamforming core to generate a beamformed signal, wherein the first received signal is related to the first filtered down-sampled received digital signal, and wherein the second received signal is related to the second filtered down-sampled received digital signal.

First claim

What is claimed as new and desired to be protected by Letters Patent of the United States is:

1. A phased array receiver for use with a first received analog signal and a second received analog signal, said phased array receiver comprising:
a first analog to digital converter arranged to receive the first received analog signal and to generate a corresponding first received digital signal based on the first received analog signal;
a second analog to digital converter arranged to receive the second received analog signal and to generate a corresponding second received digital signal;
a first down-sampler operable to generate a first down-sampled digital signal based on the first received digital signal;
a second down-sampler operable to generate a second down-sampled digital signal based on the second received digital signal;
a first polyphase low pass filter operable to generate a first filtered down-sampled received digital signal based on the first down-sampled digital signal;
a second polyphase low pass filter operable to generate a second filtered down-sampled received digital signal based on the second down-sampled digital signal; and
a beamforming core operable to generate a beamformed signal based on a combination of a first received signal and a second received signal,
wherein the first received signal is related to the first filtered down-sampled received digital signal, and
wherein the second received signal is related to the second filtered down-sampled received digital signal.

2. The phased array receiver of claim 1 , wherein said beamforming core comprises an adder operable to generate the beamformed signal based on a summation.

3. The phased array receiver of claim 2 , wherein said beamforming core further comprises:
a first mixer operable to mix the first filtered down-sampled received digital signal and a first factor to generate the first received signal; and
a second mixer operable to mix the second filtered down-sampled received digital signal and a second factor to generate the second received signal.

4. The phased array receiver of claim 3 ,
wherein said first mixer is operable to mix the first filtered down-sampled received digital signal and a first complex weighting factor to generate the first received signal, and
wherein said second mixer is operable to mix the second filtered down-sampled received digital signal and a second complex weighting factor to generate the second received signal.

5. The phased array receiver of claim 3 ,
wherein said first mixer is operable to mix the first filtered down-sampled received digital signal and a first time delay factor to generate the first received signal, and
wherein said second mixer is operable to mix the second filtered down-sampled received digital signal and a second time delay factor to generate the second received signal.

6. The phased array receiver of claim 1 , wherein said beamforming core further comprises:
a first mixer operable to mix the first filtered down-sampled received digital signal and a first factor to generate the first received signal; and
a second mixer operable to mix the second filtered down-sampled received digital signal and a second factor to generate the second received signal.

7. The phased array receiver of claim 6 ,
wherein said first mixer is operable to mix the first filtered down-sampled received digital signal and a first complex weighting factor to generate the first received signal, and
wherein said second mixer is operable to mix the second filtered down-sampled received digital signal and a second complex weighting factor to generate the second received signal.

8. The phased array receiver of claim 6 ,
wherein said first mixer is operable to mix the first filtered down-sampled received digital signal and a first time delay factor to generate the first received signal, and
wherein said second mixer is operable to mix the second filtered down-sampled received digital signal and a second time delay factor to generate the second received signal.

9. A phased array transmitter for use with a driving signal, said phased array transmitter comprising:
a beamforming core operable to generate a first weighted driving signal and a second weighted driving signal based on the driving signal,
a first polyphase low pass filter operable to generate a first filtered weighted driving signal based on the first weighted driving signal;
a second polyphase low pass filter operable to generate a second filtered weighted driving signal based on the second weighted driving signal; and
a first up-sampler operable to generate a first up-sampled digital signal based on the first filtered weighted driving signal;
a second up-sampler operable to generate a second up-sampled digital signal based on the second filtered weighted driving signal;
a first digital to analog converter operable to generate a first analog signal based on the first up-sampled digital signal; and
a second digital to analog converter operable to generate a second analog signal based on the second up-sampled digital signal.

10. The phased array transmitter of claim 9 , wherein said beamforming core comprises a divider operable to generate a first driving signal and a second driving signal based on the driving signal.

11. The phased array transmitter of claim 10 , wherein said beamforming core further comprises:
a first mixer operable to mix the first driving signal and a first factor to generate the first weighted driving signal; and
a second mixer operable to mix the second driving signal and a second factor to generate the second weighted driving signal.

12. The phased array transmitter of claim 11 ,
wherein said first mixer is operable to mix the first driving signal and a first complex weighting factor to generate the first weighted driving signal, and
wherein said second mixer is operable to mix the second driving signal and a second complex weighting factor to generate the second weighted driving signal.

13. The phased array transmitter of claim 11 ,
wherein said first mixer is operable to mix the first driving signal and a first time delay factor to generate the first weighted driving signal, and
wherein said second mixer is operable to mix the second driving signal and a second time delay factor to generate the second weighted driving signal.

14. A method of receiving on a phased array receiver with a first received analog signal and a second analog received signal, said method comprising:
generating, via a first analog to digital converter arranged to receive the first received analog signal, a corresponding first received digital signal based on the first received analog signal;
generating, via a second analog to digital converter arranged to receive the second received analog signal, a corresponding second received digital signal;
generating, via a first down-sampler, a first down-sampled digital signal based on the first received digital signal;
generating, via a second down-sampler, a second down-sampled digital signal based on the second received digital signal;
generating, via a first polyphase low pass filter, a first filtered down-sampled received digital signal based on the first down-sampled digital signal;
generating, via a second polyphase low pass filter, a second filtered down-sampled received digital signal based on the second down-sampled digital signal; and
generating, via a beamforming core, a beamformed signal based on a combination of a first received signal and a second received signal,
wherein the first received signal is related to the first filtered down-sampled received digital signal, and
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Assignees

• Spawar Systems Ct Pacific
• Us Navy

Inventors

• Chieh Jia-Chi Samuel
• Civerolo Michael

Classifications

• H04B7/043

  using best eigenmode, e.g. beam forming or beam steering · CPC title

• H04B7/086

  using weights depending on external parameters, e.g. direction of arrival [DOA], predetermined weights or beamforming · CPC title

• H04B7/0617 Primary

  for beam forming · CPC title

• H04B1/0025 Primary

  using a sampling rate lower than twice the highest frequency component of the sampled signal (for demodulation of angle-modulated signals H03D3/006) · CPC title