Data stream transmission preprocessing
View Patent ↗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.
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.
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.
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.