Systems and methods for transmitter diversity expansion
View Patent ↗Methods and systems for transmitter diversity expansion are provided. The methods and systems include steps and modules for applying a number of data streams (K) to a larger number of antennas (N). This is performed by applying each of the data streams to a single base antenna, such that K data streams are applied to K base antennas, and by shifting and combining the K data streams to produce N-K data streams to apply to N-K extension antennas.
1. A method comprising:
receiving a first set of data streams;
generating a second set of one or more data streams based on a combination of the first set of data streams, wherein the combination of the first set of data streams is the product of a matrix multiplication of the data in the first set of data streams with a unitary matrix; and
transmitting each data stream of the first and second sets of data streams from a separate antenna.
2. The method of claim 1 , wherein the second set of data streams comprises at least one data stream corresponding to a cyclically-shifted combination of the data streams of the first set of data streams.
3. The method of claim 1 , wherein at least one data stream of the first set of data streams is cyclically-shifted before it is combined with the other data streams of the first set of data streams to generate the second set of data streams.
4. The method of claim 1 , wherein generating the second set of data streams based on a combination of the first set of data streams comprises:
combining the first set of data streams into a combined data stream; and
cyclically-shifting the combined data stream to generate at least one data stream of the second set of data streams.
5. The method of claim 1 , wherein generating the second set of data streams based on a combination of the first set of data streams comprises:
cyclically-shifting at least one data stream of the first set of data streams; and
combining the at least one cyclically-shifted data stream with at least one other data stream of the first set of data streams.
6. The method of claim 1 , wherein the unitary matrix is one of a Fourier Transform matrix or a Walsh matrix.
7. A system comprising:
a signal processor configured to receive a first set of data streams, and generate a second set of one or more data streams based on a combination of the first set of data streams, wherein the combination of the first set of data streams is the product of a matrix multiplication of the data in the first set of data streams with a unitary matrix; and
a plurality of antennas, wherein each antenna is configured to transmit a corresponding one data stream of the first and second sets of data streams.
8. The system of claim 7 , wherein the second set of data streams comprises at least one data stream corresponding to a cyclically-shifted combination of the data streams of the first set of data streams.
9. The system of claim 7 , wherein at least one data stream of the first set of data streams is cyclically-shifted before it is combined with the other data streams of the first set of data streams to generate the second set of data streams.
10. The system of claim 7 , wherein generating the second set of data streams based on a combination of the first set of data streams comprises:
combining the first set of data streams into a combined data stream; and
cyclically-shifting the combined data stream to generate at least one data stream of the second set of data streams.
11. The system of claim 7 , wherein generating the second set of data streams based on a combination of the first set of data streams comprises:
cyclically-shifting at least one data stream of the first set of data streams; and
combining the at least one cyclically-shifted data stream with at least one other data stream of the first set of data streams.
12. The system of claim 7 , wherein the unitary matrix is one of a Fourier Transform matrix or a Walsh matrix.
13. A computer-readable medium having instructions stored thereon that, if executed by a device, cause the device to perform a method comprising:
receiving a first set of data streams; and
generating a second set of one or more data streams based on a combination of the first set of data streams, wherein the combination of the first set of data streams is the product of a matrix multiplication of the data in the first set of data streams with a unitary matrix;
transmitting each data stream of the first and second sets of data streams from a separate antenna.
14. The computer-readable medium of claim 13 , wherein the second set of data streams comprises at least one data stream corresponding to a cyclically-shifted combination of the data streams of the first set of data streams.
15. The computer-readable medium of claim 13 , wherein at least one data stream of the first set of data streams is cyclically-shifted before it is combined with the other data streams of the first set of data streams to generate the second set of data streams.
16. The computer-readable medium of claim 13 , wherein generating the second set of data streams based on a combination of the first set of data streams comprises:
combining the first set of data streams into a combined data stream; and
cyclically-shifting the combined data stream to generate at least one data stream of the second set of data streams.
17. The computer-readable medium of claim 13 , wherein generating the second set of data streams based on a combination of the first set of data streams comprises:
cyclically-shifting at least one data stream of the first set of data streams; and
combining the at least one cyclically-shifted data stream with at least one other data stream of the first set of data streams.
18. The computer-readable medium of claim 13 , wherein the unitary matrix is one of a Fourier Transform matrix or a Walsh matrix.