Data stream transmission preprocessing

• US 7,430,163 B2
• Filed: 07/19/2004
• Issued: 09/30/2008
• Est. Priority Date: 07/19/2004
• Status: Expired due to Fees

• Current Assignee: Novanta Inc.
• Original Assignee: TZero Technologies Incorporated (Novanta Inc.)
• Inventors: Chari, Sujai, Krishnomoorthy, Rajeev
• Primary Examiner(s): Yao; Kwang B.
• Assistant Examiner(s): Kao; Jutai
• Application Number:
  US10/893,810
• Publication Number:
  US 20060013259A1
• Time in Patent Office: 1,534 Days
• Field of Search: None
• US Class Current: 370/208
• CPC Class Codes: H04B 1/71632 Signal aspects H04B1/7172 and H04B1/7176 take precedence
• CPC Class Codes: H04L 27/2602 Signal structure

Abstract

Embodiments of transmission data stream pre-processing are disclosed. A method includes receiving the data stream for transmission, forming blocks of samples from the data stream, inverse Fourier transforming the blocks of samples forming multi-carrier signal symbols, selecting sets of k multi-carrier signal symbols and time expanding each of the sets of the k multi-carrier signal symbols into sets of n multi-carrier signal symbols, where n is greater than k, and transmitting each of the n multi-carrier signal symbols. The time expansion can be accomplished by coding the coding the sets of k multi-carrier signal symbols.

Claims

1. A method of pre-processing a data stream for transmission, comprising:

receiving the data stream for transmission;

forming blocks of samples from the data stream;

inverse Fourier transforming the blocks of samples forming multi-carrier signal symbols; and

selecting sets of k multi-carrier signal symbols, and time expanding each of the sets of the k multi-carrier signal symbols into sets of n multi-carrier signal symbols, where n is greater than k;

wherein

time expanding comprises selecting coding of the sets of the k multi-carrier signal symbols based upon a chip offset and a fractional symbol offset of a desired symbol and an interfering symbol.

2. The method of pre-processing a data stream of claim 1, transmitting each of the n multi-carrier signal symbols.

3. The method of pre-processing a data stream of claim 1, wherein the multi-carrier signal symbols include OFDM symbols.

4. The method of pre-processing a data stream of claim 1, wherein k=1.

5. The method of pre-processing a data stream of claim 1, further comprising frequency expanding the multi-carrier signal symbols.

6. The method of pre-processing a data stream of claim 5, wherein the frequency expansion expands the multi-carrier symbols into more than one designated frequency band, and different frequency bands are transmitted at different times.

7. The method of pre-processing a data stream of claim 5, wherein frequency expanding the multi-carrier signal symbols comprises coding the multi-carrier signal symbols, thereby increasing a bit length of the multi-carrier signal symbols.

8. The method of pre-processing a data stream of claim 1, further comprising space expanding the multi-carrier signal symbols.

9. The method of pre-processing a data stream of claim 8, wherein space expanding comprises space coding the multi-carrier signal symbols for transmission through spatially separate antennas.

10. The method of pre-processing a data stream of claim 5, further comprising space expanding the multi-carrier signal symbols.

11. The method of pre-processing a data stream of claim 10, wherein space expanding comprises space coding the multi-carrier signal symbols for transmission through spatially separate antennas.

12. The method of pre-processing a data stream of claim 1 wherein coding the sets of k multi-carrier symbols includes a set of 1 and −

1 multipliers of each of the multi-carrier signal symbols, forming n coded multi-carrier signal symbols for each of the sets of k multi-carrier signal symbols.

13. The method of pre-processing a data stream of claim 1, wherein the time expanding of each of the sets of the k multi-carrier signal symbols is dependent upon a required transmission data rate.

14. The method of pre-processing a data stream of claim 1, further comprising:

determining a level of synchronization between a transmitter of the sets of n multi-carrier signal symbols and a receiver of the sets of n multi-carrier signal symbols, and setting the time expanding to a desired code.

15. The method of pre-processing a data stream of claim 1, wherein the selected coding comprises a Gold code.

16. The method of pre-processing a data stream of claim 1, further comprising:

selecting the coding to minimize cross-correlation with interfering transmitters, wherein the interfering transmitters include coding of multi-carrier signal symbols according to a different code.

17. The method of pre-processing a data stream of claim 16, wherein the selected coding comprises a Gold code.

18. The method of pre-processing a data stream of claim 16, wherein code of interfering transmitters is deduced by comparing received symbols with known training sequences.

19. The method of pre-processing a data stream of claim 1, further comprising:

selecting a length of coding to minimize cross-correlation with interfering transmitters.

20. The method of pre-processing a data stream of claim 19, wherein the selection of the length is based upon a set of available lengths.

21. The method of pre-processing a data stream of claim 14, wherein the selected code comprises a Walsh code if the transmitter and the receiver are synchronized.

22. The method of pre-processing a data stream of claim 1, wherein the chip offset between transmitter and the receiver is adjusted to optimize cross-correlation gain.

33. The method of claim 1, further comprising adaptively selecting coding of the sets of the k multi-carrier signal symbols based upon a chip offset and a fractional symbol offset of a desired symbol and an interfering symbol.

34. The method of claim 1, wherein selecting the coding is additionally based on coding used by interfering transmitters.

35. The method of claim 1, further comprising detecting the chip offset, comprising detecting synchronization sequences within first multi-carrier symbols with in received packets.

36. The method of claim 1, further comprising controlling chip offset, comprising adjusting timing of transmission symbols.

23. A method of pre-processing a data stream for transmission, comprising:

receiving the data stream;

forming blocks of samples from the data stream;

generating coded patterns of each of the blocks of samples; and

inverse Fourier transforming the blocks of samples forming coded patterns of multi-carrier signal symbols;

wherein

the coded patterns of multi-carrier signal symbols are based upon a chip offset and a fractional symbol offset of a desired symbol and an interfering symbol.

24. The method of pre-processing a data stream of claim 23, wherein the multi-carrier signal symbols include OFDM symbols.

25. The method of pre-processing a data stream of claim 23, further comprising frequency expanding the multi-carrier signal symbols.

26. The method of pre-processing a data stream of claim 25, wherein frequency expanding the multi-carrier signal symbols comprises coding the multi- carrier signal symbols, thereby increasing a bit length of the multi-carrier signal symbols.

27. The method of pre-processing a data stream of claim 23, further comprising space expanding the multi-carrier signal symbols.

28. The method of pre-processing a data stream of claim 27, wherein space expanding comprises space coding the multi-carrier signal symbols for transmission through spatially separate antennas.

29. The method of pre-processing a data stream of claim 23, further comprising:

determining a level of synchronization between a transmitter of the sets of n multi-carrier signal symbols and a receiver of the sets of n multi-carrier signal symbols, and setting the time expanding to a desired code.

30. The method of pre-processing a data stream of claim 23, further comprising:

selecting the coding to minimize cross-correlation with interfering transmitters, wherein the interfering transmitters include coding of multi-carrier signal symbols according to a different code.

31. A wideband, low-power transmission system comprising:

a transmitter comprising;

means for receiving the data stream for transmission;

means for forming blocks of samples from the data stream;

means for inverse Fourier transforming the blocks of samples forming multi-carrier signal symbols;

means for selecting sets of k multi-carrier signal symbols, and time expanding each of the sets of the k multi-carrier signal symbols into sets of n multi-carrier signal symbols, where n is greater than k;

wherein

time expanding comprises selecting coding of the sets of the k multi-carrier signal symbols based upon a chip offset and a fractional symbol offset of a desired symbol and an interfering symbol;

means for transmitting each of the n multi-carrier signal symbols;

a receiver comprising;

means for receiving the n multi-carrier signal symbols;

means for time compressing n sets received multi-carrier signal symbols to k multi-carrier symbols;

means for Fourier transforming the multi-carrier symbols forming blocks of samples; and

means for forming a data stream from the blocks of samples.

32. A networked of electronic multi-media components, wherein each of the electronic components comprises a transmitter, each transmitter comprising:

means for receiving the data stream for transmission;

means for forming blocks of samples from the data stream;

means for inverse Fourier transforming the blocks of samples forming multi-carrier signal symbols;

means for selecting sets of k multi-carrier signal symbols, and time expanding each of the sets of the k multi-carrier signal symbols into sets of n multi-carrier signal symbols, where n is greater than k;

wherein

time expanding comprises selecting coding of the sets of the k multi-carrier signal symbols based upon a chip offset and a fractional symbol offset of a desired symbol and an interfering symbol;

means for transmitting each of the n multi-carrier signal symbol.