1. A method of depositing silicon onto a carbon material to form an alloy for use in lithium ion batteries comprising: providing a carbon material selected from vapor grown carbon fibers, vapor grown carbon nanofibers, and PAN or pitch derived carbon fibers; wherein said carbon material further includes a carbide material selected from metal carbides, and silicon carbides; heating said carbon material at a temperature between about 100\xb0 C. to about 1200\xb0 C.; flowing a silicon-containing precursor gas in contact with said carbon material for a time sufficient for said gas to decompose and form a coating on at least the surface of said carbon material.
2. The method of claim 1 wherein said precursor gas comprises silane, a blend of silane and hydrogen, or a blend of silane and an inert gas.
3. The method of claim 1 wherein said carbon material comprises vapor grown carbon nanofibers.
4. The method of claim 3 wherein said vapor grown carbon nanofibers have been heated treated at a temperature above 700\xb0 C.
5. The method of claim 1 wherein said carbon material further includes a carbon or graphite additive selected from single-walled carbon nanotubes, multi-walled carbon nanotubes, exfoliated graphite flakes, graphite platelets, graphene particles, carbon black, and mesocarbon microbeads.
6. The method of claim 1 wherein said carbon material further includes a conductive additive comprising macroscopic vapor grown carbon nanofibers having a diameter of from about 500 nm to 10 micrometers.
7. The method of claim 1 wherein said carbon material has a length of from about 1 to about 500 micrometers.
8. The method of claim 1 wherein said carbon material is in the form of a composite or preform.
9. The method of claim 1 wherein said silicon is coated onto said carbon material at a thickness of about 0.001 and 100 microns.
10. The method of claim 1 wherein said silicon is coated onto said carbon material at a thickness of about 2 to 100 nm.
11. The method of claim 1 wherein said silicon-coated carbon material has a graded interface.
12. The method of claim 1 further including forming an anode by adding a binder to said silicon-coated carbon material.
13. The method of claim 12 wherein said binder is selected from polyvinylidene difluoride, EPDM, and polystyrene.
14. A method of depositing silicon onto a carbon material to form an alloy for use in lithium ion batteries comprising:
providing a carbon material selected from vapor grown carbon fibers, vapor grown carbon nanofibers, and PAN or pitch derived carbon fibers;
heating said carbon material at a temperature between about 100\xb0 C. to about 1200\xb0 C.;
flowing a silicon-containing precursor gas in contact with said carbon material for a time sufficient for said gas to decompose and form a coating on at least the surface of said carbon material; wherein said silicon-coated carbon material has a graded interface.
15. The method of claim 14 wherein said precursor gas comprises silane, a blend of silane and hydrogen, or a blend of silane and an inert gas.
16. The method of claim 14 wherein said carbon material comprises vapor grown carbon nanofibers.
17. The method of claim 14 further including forming an anode by adding a binder to said silicon-coated carbon material.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A receiver provided in a MC-CDMA (multi-carrier code division multiple access) communication system, comprising:
a CP (cyclic prefix) removal unit configured to remove a CP from a time-domain signal;
a fast Fourier transform (FFT) unit configured to generate a frequency-domain signal by means of performing Fourier transform for the time-domain signal without the CP;
a frequency-domain equalizer (FDE) configured to generate an equalized signal by means of performing frequency-domain equalization for the frequency-domain signal;
a CSOK despread spectrum unit configured to receive the equalized signal and a base code and to convert the equalized signal into a despread spectrum signal;
a CSOK decision unit configured to receive the despread spectrum signal and to convert the despread spectrum signal into a modulation symbol estimation value and a CSOK symbol estimation value according to a decision mechanism;
a modulation symbol demapping unit configured to receive the modulation symbol estimation value and to generate a first part of data bits by means of a demapping process;
a CSOK (cyclic-shift orthogonal keying) symbol demapping unit configured to receive the CSOK symbol estimation value and to generate a second part of data bits by means of a CSOK demapping process; and
a parallel-to-serial converter (PS converter) configured to generate a serial data bits based on addition of the first and second parts of data bits.
2. The receiver in accordance with claim 1, wherein the CSOK despread spectrum unit further comprises a code correlation bank when performing the time-domain despread spectrum.
3. The receiver in accordance with claim 1, wherein the CS OK despread spectrum unit further comprises a Fourier transform unit, a multiplier, a SP converter and an IFFT (inversed fast Fourier transform) unit when performing frequency-domain despread spectrum.
4. The receiver in accordance with claim 1, wherein the decision mechanism is determined based on a maximum likelihood based rule.
5. The receiver in accordance with claim 1, wherein the FDE is configured to perform frequency-domain equalization and to generate an equalized signal by means of using a maximum ratio combining (MRC) method.
6. A receiver provided in a MC-CDMA communication system, comprising:
a CP removal unit configured to remove a CP from a time-domain signal;
a FFT unit configured to generate a frequency-domain signal by means of performing Fourier transform to the time-domain signal without the CP;
a FDE configured to generate an equalized signal by means of performing frequency-domain equalization to the frequency-domain signal;
a CSOK despread spectrum unit configured to receive the equalized signal and a base code so as to generate a despread spectrum signal;
a CSOK decision unit configured to receive the despread spectrum signal and to convert the despread spectrum signal into a first modulation symbol estimation value, a first CSOK symbol estimation value, a second modulation estimation value and a second CSOK symbol estimation value according to a decision mechanism;
a first modulation symbol demapping unit configured to receive the first modulation symbol estimation value and to demap the first modulation symbol estimation value;
a second modulation symbol demapping unit configured to receive the second modulation symbol estimation value and to demap the second modulation symbol estimation value;
a first CSOK symbol demapping unit configured to receive the first CSOK symbol estimation value and to demap the first CSOK symbol estimation value;
a second CSOK symbol demapping unit configured to receive the second CSOK symbol estimation value and to demap the second CSOK symbol estimation value; and
a PS converter configured to generate an estimated first set of data bits and an estimated second set of data bits in a serial manner after performing the first and second modulation symbol demapping units and the first and second CSOK symbol demapping units.
7. The receiver in accordance with claim 6, wherein the despread spectrum signal further comprises a real despread spectrum signal and an imaginary despread spectrum signal.
8. The communication system in accordance with claim 6, wherein the FDE is configured to perform the frequency-domain equalization by means of using a MRC method.