Low-complexity diversity using coarse FFT and subband-wise combining
View Patent ↗A wireless diversity receiver includes, in part, N signal processing paths, a bin-wise combiner, and an inverse transformation module. Each signal processing path includes, in part, a mixer adapted to downconvert a frequency of an RF signal received by that path, an analog-to-digital converter adapted to convert the downconverted signal from an analog signal to a digital signal, and a transformation block adapted to transform the digital signal represented in time domain to an associated frequency domain signal having M subband signals. The bin-wise combiner is configured to combine the corresponding subband signals of the N paths. The inverse transformation block is configured to transform the output of the bin-wise combiner to an associated time-domain signal.
1. A wireless receiver comprising:
N signal processing paths, each signal processing path comprising:
a mixer adapted to downconvert a frequency of an RF signal received by the path;
an analog-to digital converter adapted to convert the downconverted signal from an analog signal to a digital signal; and
a transformation block adapted to transform the digital signal represented in time domain to an associated frequency domain signal having M subband signals;
a bin-wise combiner adapted to combine corresponding subband signals of the N paths; and
an inverse transformation block adapted to transform output of the bin-wise combiner to an associated time-domain signal.
2. The wireless receiver of claim 1 wherein each signal path further comprises an amplifier adapted to amplify the RF signal received by the path.
3. The wireless receiver of claim 2 wherein said amplifier is a low-noise amplifier.
4. The wireless receiver of claim 2 wherein said transformation block in each path is a Fourier transformer.
5. The wireless receiver of claim 2 further comprising:
a filter responsive to the inverse transformation block.
6. The wireless receiver of claim 5 further comprising:
a variable gain stage responsive to the filter.
7. A method of processing signals in a receiver having N signal processing paths, the method comprising:
downconverting an RF signal received in each path;
converting each downconverted RF signal to an associated digital signal;
transforming each digital signal represented in time domain to an associated frequency domain signal having M subband signals;
combining a plurality of the subband signals of each of the paths; and
performing an inverse transformation to transform the combined subband signals to an associated time-domain signal.
8. The method of claim 7 further comprising:
amplifying the RF signal received in each path.
9. The method of claim 8 wherein said amplifier is a low-noise amplifier.
10. The method of claim 7 further comprising:
transforming each digital signal represented in time domain to an associated frequency domain signal using a Fourier transform module.
11. The method of claim 8 further comprising:
filtering the time domain signal that is generated by performing the inverse transformation.
12. The method of claim 11 further comprising:
varying a gain of an amplification stage amplifying the filtered signal.