Training prefix modulation method and receiver

• US 6,885,708 B2
• Filed: 07/18/2002
• Issued: 04/26/2005
• Est. Priority Date: 07/18/2002
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Baum, Kevin L., Nangia, Vijay, Vook, Frederick W., Thomas, Timothy A.
• Primary Examiner(s): Vo, Don N.
• Application Number:
  US10/198,487
• Publication Number:
  US 20040013084A1
• Time in Patent Office: 1,013 Days
• Field of Search: 370/203, 370/204, 370/208, 370/210, 375/260, 375/231, 375/295, 375/346, 375/348, 375/350, 342/372, 342/378, 342/368, 342/383
• US Class Current: 375/260
• CPC Class Codes: H04L 2025/03414 Multicarrier
• CPC Class Codes: H04L 2025/03522 Frequency domain
• CPC Class Codes: H04L 25/0226 sounding signals per se
• CPC Class Codes: H04L 25/03006 Arrangements for removing intersymbol interference
• CPC Class Codes: H04L 27/2605 Symbol extensions, e.g. Zero Tail, Unique Word [UW]
• CPC Class Codes: H04L 27/2607 Cyclic extensions

Abstract

A receiver for implementing a training prefix modulation method in response to a reception of a signal propagating through a channel is disclosed. The signal as received includes training blocks with each training block having a data inter-block-interference therein, and data blocks with each data block having a training inter-block-interference therein. The signal is selectively reconstructed to provide a circular appearance of the channel over the data blocks. Specifically, an estimate of the training inter-block-interferences is generated and subtracted from the data blocks. And, an estimate of the data inter-block interferences is generated and added to the data blocks.

Claims

1. A method for reconstructing a signal including a data block having a first inter-block-interference and a training block having a second inter-block-interference, said method comprising:

reconstructing the data block to exclude the first inter-block-interference; and

reconstructing the data block to include the second inter-block-interference.

2. The method of claim 1, further comprising;

transforming the reconstructed data block into a frequency domain data block; and

detecting symbols based on at least the frequency domain data block.

3. The method of claim 1,

wherein the reconstruction provides a reconstructed data block having a characteristic of circular convolution with a channel pulse response;

and

further comprising processing the reconstructed data block based on the circular convolution property and an estimate of the channel pulse response to facilitate data detection.

4. The method of claim 1, wherein the estimate of the channel pulse response is represented in the frequency domain.

5. A receiver, comprising:

a buffer operable to store a signal including a data block having a first inter-block-interference and a training block having a second inter-block-interference; and

one or more modules operable to reconstruct the data block to exclude the first inter-block-interference and to include the second inter-block-interference.

6. A method for reconstructing a signal including a data block having a first inter-block-interference and a training block having a second inter-block-interference, said method comprising:

replacing the training block with a null block; and

constructing the null block to include the second inter-block-interference.

7. The method of claim 6, wherein the step of constructing the null block to include the second inter-block-interference includes:

generating an estimate of the second inter-block-interference; and

adding the estimate of the second inter-block-interference to the null block.

8. The method of claim 6, further comprising reconstructing the data block to exclude the first inter-block-interference.

9. The method of claim 8, wherein the step of reconstructing the data block to exclude the first inter-block-interference includes:

generating an estimate of the first inter-block-interference; and

subtracting the estimate of the first inter-block-interference from the data block.

10. A receiver, comprising:

a buffer operable to store a signal including a data block having a first inter-block-interference and a training block having a second inter-block-interference; and

one or more modules operable to replace the training block with a null block and to construct the null block to include the second inter-block-interference.

11. The receiver of claim 10, wherein said one or more modules are further operable to generate an estimate of the second inter-block-interference, and to add the estimate of the second inter-block-interference to the null block to construct the null block to include the second inter-block-interference.

12. The receiver of claim 10, wherein said one or more modules are further operable to reconstruct the data block to exclude the first inter-block-interference.

13. The receiver of claim 12, wherein said one or more modules are further operable to generate an estimate of the first inter-block interference and subtract the estimate of the first inter-block interference from the data block to reconstruct the data block to exclude the first inter-block-interference.

14. A method for processing a signal propagating through a channel, the signal including a data block and a training block, the data block including information and a first inter-block-interference, the training block including a second inter-block-interference, said method comprising:

receiving the signal;

selectively executing one or more reconstructions of the data block to exclude the first inter-block-interference and to include the second inter-block-interference; and

demodulating the signal as received or reconstructed whereby the information is detected.

15. A receiver for receiving a signal propagating through a channel, the signal including a data block and a training block, the data block including information and a first inter-block-interference, the training block including a second inter-block-interference, said receiver comprising:

a buffer operable to store the signal; and

one or more modules operable to executing one or more reconstructions of the data block to exclude the first inter-block-interference and to include the second inter-block-interference, said one or more modules further operable to demodulate the signal as received or as reconstructed whereby the information is detected.

16. A method for reconstructing a signal including a data block having a first inter-block-interference and a training block having a second inter-block-interference, said method comprising:

generating an estimate of the first inter-block interference;

subtracting the estimate of the first inter-block interference from the data block; and

reconstructing the data block to include the second inter-block-interference.

17. The method of claim 16, wherein the estimate of the first inter-block interference is generated according to:

$t_l^{\text{\hspace{1em}<br><br>}<br><br>\mathrm{ibi}}=\underset{m=0}{\overset{M}{\sum <br><br>}}<br><br>t_{l+v-m}·<br><br>{\hat{p}}_l^a<br><br>\text{\hspace{1em}<br><br>}<br><br>l=0<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{\dots <br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>\left(M-1\right).$

18. A method for reconstructing a signal including a data block having a first inter-block-interference and a training block having a second inter-block-interference, said method comprising:

reconstructing the data block to exclude the first inter-block-interference;

generating an estimate of the second inter-block interference; and

adding the estimate of the second inter-block interference to the data block.

19. The method of claim 18, wherein the estimate of the second inter-block interference is generated according to:

$d_l^{\text{\hspace{1em}<br><br>}<br><br>\mathrm{ibi}}=\left(1-\mathrm{\alpha <br><br>}\right)·<br><br>\left(y_{N+1}-\underset{m=0}{\overset{M}{\sum <br><br>}}<br><br>t_{l-m}·<br><br>{\hat{p}}_m^b\right)+\mathrm{\alpha <br><br>}<br><br>\underset{m=0}{\overset{M}{\sum <br><br>}}<br><br>{\hat{x}}_{l+N-m}·<br><br>{\hat{p}}_m^c<br><br>\text{\hspace{1em}<br><br>}<br><br>l=0<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{\dots <br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>\left(M-1\right).$

20. A receiver, comprising:

a buffer operable to a store a signal including a data block having a first inter-block-interference and a training block having a second inter-block-interference; and

one or more modules operable to generate an estimate of the first inter-block-interference, to subtract the estimate of the first inter-block-interference from the data block, and to reconstruct the data block to include the second inter-block-interference.

21. The receiver of claim 20, wherein said one or more modules generate an estimation of the first inter-block-interference according to:

$t_l^{\text{\hspace{1em}<br><br>}<br><br>\mathrm{ibi}}=\underset{m=0}{\overset{M}{\sum <br><br>}}<br><br>t_{l+v-m}·<br><br>{\hat{p}}_l^a<br><br>\text{\hspace{1em}<br><br>}<br><br>l=0<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{\dots <br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>\left(M-1\right).$

22. A receiver, comprising:

a buffer operable to store a signal including a data block having a first inter-block-interference and a training block having a second inter-block-interference; and

one or more modules operable to reconstruct the data block to exclude the first inter-block-interference, to generate an estimate of the second inter-block-interference, and to add the estimate of the second inter-block-interference to the data block.

23. The receiver of claim 22, wherein said one or more modules generate an estimation of the second inter-block interference according to:

$d_l^{\mathrm{ibi}}=\left(1-\mathrm{\alpha <br><br>}\right)·<br><br>\left(y_{N+l}-\underset{m=0}{\overset{M}{\sum <br><br>}}<br><br>\text{\hspace{1em}<br><br>}<br><br>t_{l-m}·<br><br>{\hat{p}}_m^b\right)+\mathrm{\alpha <br><br>}<br><br>\underset{m=0}{\overset{M}{\sum <br><br>}}<br><br>{\hat{x}}_{l+N-m}·<br><br>{\hat{p}}_m^c<br><br>\text{\hspace{1em}<br><br>}<br><br>l=0<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{\dots <br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>\left(M-1\right).$

24. A method for facilitating a detection of data symbols within a received signal block, said method comprising:

applying frequency-domain equalization to the received signal;

transforming the equalized frequency-domain signal from the frequency domain to an equalized time domain signal;

removing a guard period from the equalized time-domain signal; and

transforming the equalized time-domain signal without the guard period from the time domain to the frequency domain.

25. A receiver, comprising:

a buffer operable to store a signal including a data block and a guard period; and

one or more modules operable to apply frequency-domain equalization to the signal, to transform the equalized signal from the frequency domain to an equalized time-domain signal, to remove the guard period from the equalized time-domain signal, and to transform the equalized time-domain signal without the guard period from the time domain to the frequency domain.

26. A method for processing a signal including a data block having a first inter-block-interference and a training block having a second inter-block-interference, said method comprising:

generating an estimate of the first inter-block interference and the second inter-block interference;

detecting a plurality of symbols within the data block based upon the estimate of the first inter-block interference and the estimate of the second inter-block interference;

remodulating the detected symbols; and

resynthesizing the estimate of the first inter-block interference and the estimate of the second inter-block interference based upon the remodulation of the detected symbols.

27. The method of claim 26, wherein the detecting a plurality of symbols within the data block is further based on the output of a channel decoder.

28. A receiver, comprising:

a buffer operable to store a signal including a data block and a guard period; and

one or more modules operable to generate an estimate of the first inter-block interference and the second inter-block interference, to detect a plurality of symbols within the data block based upon the estimate of the first inter-block interference and the estimate of the second inter-block interference, to remodulate the detected symbols; and

to resynthesize the estimate of the first inter-block interference and the estimate of the second inter-block interference based upon the remodulation of the detected symbols.

29. A method for creating a multicarrier signal having no cyclic extensions, the method comprising the steps of:

generating a plurality of multicarrier data blocks, each multicarrier data block having no cyclic extension;

generating a plurality of training sequences that are not copies of portions of the plurality of multicarrier data blocks;

extending each of the plurality of multicarrier data blocks by adding one of the plurality of training sequences to create the multicarrier signal.

30. The method of claim 29 wherein the step of extending each of the multicarrier data blocks comprises the step of extending the multicarrier data blocks by adding one of the plurality of training sequences as either a prefix, a postfix, or a combination of a prefix and a postfix.

31. The method of claim 29 wherein the step of generating the plurality of multicarrier data blocks each multicarrier data block having no cyclic extension, comprises the step of generating the multicarrier data stream comprising the plurality of multicarrier data blocks each multicarrier data block having no cyclic prefix.

32. The method of claim 29 wherein the step of generating the plurality of training sequences comprises the step of generating a single training sequence that is not a copy of a multicarrier data block.

33. A method for creating a multicarrier signal, the method comprising the steps of:

generating a plurality of multicarrier data blocks;

generating a training sequence, that is not a copy of a portion of the multicarrier data blocks;

extending a multicarrier data block by adding the training sequence to create the multicarrier signal, wherein there exists no cyclic extension between the data block and the training sequence.

34. The method of claim 33 wherein the step of extending the multicarrier data block comprises the stop of extending the multicarrier data block by adding the training sequence as either a prefix, a postfix, or a combination of a prefix and a postfix.

35. The method of claim 33 further comprising the step of:

extending a plurality of the multicarrier data blocks by adding the training sequence to each of the plurality of multicarrier data blocks to create the multicarrier signal, wherein there exists no cyclic extension between each of the plurality of the data blocks and the training sequence.