Frequency-domain MIMO processing method and system

• US 6,912,195 B2
• Filed: 10/28/2001
• Issued: 06/28/2005
• Est. Priority Date: 12/28/2001
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Vook, Frederick W., Thomas, Timothy A.
• Primary Examiner(s): Pezzlo, John
• Assistant Examiner(s): Tsegaye, Saba
• Application Number:
  US10/032,602
• Publication Number:
  US 20030095573A1
• Time in Patent Office: 1,339 Days
• Field of Search: 370/203, 370/208, 370/210, 370/310, 370/319, 370/321, 370/330, 370/344, 375/267, 375/299, 375/346, 375/347, 375/269, 375/278, 375/285, 375/296
• US Class Current: 370/208
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04L 2025/03382 Single of vestigal sideband
• CPC Class Codes: H04L 2025/03522 Frequency domain
• CPC Class Codes: H04L 25/03159 operating in the frequency domain H04L25/03165, H04L25/03178 take precedence

Abstract

A communication system based upon frequency-domain MIMO processing is disclosed. A transmitting device of the communication system transforms time-domain signals into frequency-domain signals, and weights each frequency-domain signal to form weighted frequency-domain signals with each weighted frequency-domain signal being a function of each frequency-domain signal. The transmitting device transmits weighted time-domain waveforms as a function of the weighted frequency-domain signals. In response thereto, a receiving device of the communication system provides frequency-domain samples that are a function of the one or more weighted time-domain waveforms and weights each frequency-domain sample to form one or more weighted frequency-domain samples with each weighted frequency-domain sample being a function of each frequency-domain sample. The receiving device decodes the weighted frequency-domain sample to obtain the information represented by the time-domain signals.

Claims

1. A transmitting device having one or more transmission branches, each transmission branch receiving a time-domain signal, said transmitting device comprising:

a first set of one or more modules operable to transform each time-domain signal into a frequency-domain signal;

a second set of one or more modules operable to apply a weight to each frequency-domain signal to form one or more weighted frequency-domain signals with each weighted frequency-domain signal being a function of each frequency-domain signal

a third set of one or more modules operable to transform each weighted frequency-domain signal into a weighted time-domain signal;

a fourth set of one or more modules operable to add a cyclic redundancy to each weighted time-domain signal to form a corresponding weighted redundant time-domain signal, wherein the cyclic redundancy is according to;

${\hat{x}}_j<br><br>\left[i\right]=\{\begin{array}{cc}<br><br>x_j<br><br>\left[i+N-L_{\mathrm{cp}}\right],& <br><br>0\le <br><br>i\le <br><br>L_{\mathrm{cp}}-1\\ <br><br>x_j<br><br>\left[i-L_{\mathrm{cp}}\right],& <br><br>L_{\mathrm{cp}}\le <br><br>i\le <br><br>N+L_{\mathrm{cp}}-1\end{array}$

or ${\hat{x}}_j<br><br>\left[i\right]=\{\begin{array}{cc}{\widehat{<br><br>x}}_j<br><br>\left[i\right],& <br><br>0\le <br><br>i\le <br><br>N-1\\ <br><br>x_j<br><br>\left[i-N\right],& <br><br>N\le <br><br>i\le <br><br>N+L_{\mathrm{cp}}-1\end{array}<br><br>\text{\hspace{1em}<br><br>}$

or any combination of the two; and

a fifth set of one or more modules operable to transmit the weighted time-domain signal.

2. The transmitting device for claim 1, wherein a transformation of each time-domain signal into a frequency-domain signal is according to:

$S_j<br><br>\left[k\right]=\underset{m=0}{\overset{N-1}{\sum <br><br>}}<br><br>s_j<br><br>\left[m\right]<br><br>{\mathrm{e<br><br>}}^{-\mathrm{j2\pi <br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>k<br><br>\text{\hspace{1em}<br><br>}<br><br>m/N}.$

3. The transmitting device for claim 1, wherein a weighting of each frequency-domain signal is according to:

$X<br><br>\left[k\right]=V<br><br>\left[k\right]<br><br>S<br><br>\left[k\right]=\underset{l=1}{\stackrel{N_S}{\sum <br><br>}}<br><br>V_l<br><br>\left[k\right]<br><br>S_l<br><br>\left[k\right]$

4. The transmitting device of claim 1, wherein a transformation of each weighted frequency-domain signal into a weighted time-domain signal is according to:

$x_j<br><br>\left[m\right]=\frac{1}{N}<br><br>\underset{k=0}{\stackrel{N-1}{\sum <br><br>}}<br><br>X_j<br><br>\left[k\right]<br><br>{\mathrm{e<br><br>}}^{+\mathrm{j2}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{\pi <br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{km}/N}$

5. The transmitting device of claim 1, further comprising:

a sixth set of one or more modules operable to shape each weighted redundant time-domain signal into a weighted time-domain waveform.

6. The transmitting device of claim 5, wherein a shaping of each weighted redundant time-domain signal into a weighted time-domain waveform is according to:

${\hat{x}}_j<br><br>\text{\hspace{1em}<br><br>}<br><br>\left(t\right)=\underset{n=0}{\overset{N+L_{\mathrm{cp}}-1}{\sum <br><br>}}<br><br>\text{\hspace{1em}<br><br>}<br><br>{\hat{x}}_j<br><br>\left[n\right]<br><br>p_{\mathrm{sr}}<br><br>\text{\hspace{1em}<br><br>}<br><br>\left(t-{\mathrm{nT}}_s\right)$