Enhanced OFDM by use of alternating polarization states

• US 20040125880A1
• Filed: 12/30/2002
• Published: 07/01/2004
• Est. Priority Date: 12/30/2002
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola Mobility, Inc. (Lenovo Group Ltd.)
• Inventors: Sibecas, Salvador, Emami, Shahriar, Stratis, Glafkos, Rasor, Gregg, Corral, Celestino
• Granted Patent: US 7,933,343 B2
• Time in Patent Office: Days
• US Class Current: 375/260
• CPC Class Codes: H01Q 21/24 Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction circularly polarised patch antennas H01Q9/0428; circularly polarised horns H01Q13/0241; cross-polarised horns H01Q13/0258; polarisation converters H01Q15/242; cross-polarised rear feeds H01Q19/136; crossed polarisation dual antenna H01Q25/001
• CPC Class Codes: H04B 7/10 Polarisation diversity; Directional diversity
• CPC Class Codes: H04L 27/2602 Signal structure
• CPC Class Codes: H04L 27/26035 Maintenance of orthogonality, e.g. for signals exchanged between cells or users, or by using covering codes or sequences using different training sequence per antenna H04B7/0684; code allocation H04J13/16
• CPC Class Codes: H04L 27/2614 Peak power aspects

Abstract

An Orthogonal Frequency Division Multiplexer (OFDM) transmitter and receiver apparatus consistent with certain embodiments of the present invention receives data to be transmitted and maps (204) a first portion of the data to a first polarization state and a second portion of the data to a second polarization state. A first transmitter (216) transmits the first portion of the data as a set of first OFDM subcarriers using an antenna (230) exhibiting a first polarization. A second transmitter (234) transmits the second portion of the data as a set of second OFDM subcarriers using an antenna (240) exhibiting a second polarization, wherein the first polarization is orthogonal to the second polarization. A receiver apparatus uses a first antenna (302) exhibiting the first polarization and a second antenna (306) exhibiting the second polarization. A first OFDM receiver (310) receives a first set of polarized OFDM subcarriers from the first antenna (302) while a second OFDM receiver (324) receives a second set of polarized OFDM subcarriers from the second antenna (306). A decoder (330) decodes the first and second sets of OFDM subcarriers and combines them into a stream of data.

Claims

1. An Orthogonal Frequency Division Multiplexer (OFDM) transmitter apparatus, comprising:

a mapper that maps a first portion of data to be transmitted to a first polarization state and a second portion of data to be transmitted to a second polarization state;

a first transmitter that transmits the first portion of the data as a set of first OFDM subcarriers using a first antenna exhibiting a first polarization; and

a second transmitter that transmits the second portion of the data as a set of second OFDM subcarriers using a second antenna exhibiting a second polarization,

wherein the first polarization is orthogonal to the second polarization.

2. The OFDM apparatus according to claim 1, wherein the first polarization comprises horizontal polarization and wherein the second polarization comprises vertical polarization.

3. The OFDM apparatus according to claim 2, wherein the first set of OFDM subcarriers are separated in frequency by a frequency spacing, and wherein the second set of OFDM subcarriers are also separated by the frequency spacing.

4. The OFDM apparatus according to claim 2, wherein the first set of OFDM subcarriers are interleaved in at least one of frequency, time and polarization with the second set of OFDM subcarriers.

5. The OFDM apparatus according to claim 1, wherein the first set of OFDM subcarriers are separated in frequency by a frequency spacing, and wherein the second set of OFDM subcarriers are also separated by the frequency spacing.

6. The OFDM apparatus according to claim 1, wherein the first set of OFDM subcarriers are interleaved in at least one of frequency, time and polarization with the second set of OFDM subcarriers.

7. An Orthogonal Frequency Division Multiplexer (OFDM) receiver apparatus, comprising:

a first antenna exhibiting a first polarization;

a second antenna exhibiting a second polarization;

a first receiver receiving a first set of polarized OFDM subcarriers from the first antenna;

a second receiver receiving a second set of polarized OFDM subcarriers from the second antenna; and

a decoder receiving the first and second sets of OFDM subcarriers from the first and second receivers and decoding the first and second sets of OFDM subcarriers into a stream of data,

wherein the first polarization is orthogonal to the second polarization.

8. The OFDM apparatus according to claim 7, wherein the first polarization comprises horizontal polarization and wherein the second polarization comprises vertical polarization.

9. The OFDM apparatus according to claim 8, wherein the first set of OFDM subcarriers are separated in frequency by a frequency spacing, and wherein the second set of OFDM subcarriers are also separated by the frequency spacing.

10. The OFDM apparatus according to claim 8, wherein the first set of OFDM subcarriers are interleaved in at least one of frequency, time and polarization with the second set of OFDM subcarriers.

11. The OFDM apparatus according to claim 7, wherein the first set of OFDM subcarriers are separated in frequency by a frequency spacing, and wherein the second set of OFDM subcarriers are also separated by the frequency spacing.

12. The OFDM apparatus according to claim 7, wherein the first set of OFDM subcarriers are interleaved in at least one of frequency, time and polarization with the second set of OFDM subcarriers.

13. A transmitter apparatus, comprising:

a mapper that maps a first portion of data to be transmitted to a first polarization state and a second portion of data to be transmitted to a second polarization state;

a first transmitter that transmits the first portion of the data using a first antenna exhibiting a first polarization; and

a second transmitter that transmits the second portion of the data using a second antenna exhibiting a second polarization,

wherein the first polarization is orthogonal to the second polarization.

14. The apparatus according to claim 13, wherein the first polarization comprises horizontal polarization and wherein the second polarization comprises vertical polarization.

15. A receiver apparatus, comprising:

a first antenna exhibiting a first polarization;

a second antenna exhibiting a second polarization;

a first receiver receiving a first signal from the first antenna;

a second receiver receiving a second signal from the second antenna; and

a decoder receiving the first and second signals from the first and second receivers and decoding the first and second signals into a stream of data,

wherein the first polarization is orthogonal to the second polarization.

16. The apparatus according to claim 15, wherein the first polarization comprises horizontal polarization and wherein the second polarization comprises vertical polarization.

17. An Orthogonal Frequency Division Multiplexing (OFDM) transmitter method, comprising:

receiving data to be transmitted;

mapping a first portion of the data to a first polarization state and a second portion of the data to a second polarization state;

transmitting the first portion of the data as a set of first OFDM subcarriers using an antenna exhibiting a first polarization; and

transmitting the second portion of the data as a set of second OFDM subcarriers using an antenna exhibiting a second polarization,

wherein the first polarization is orthogonal to the second polarization.

18. The OFDM transmitter method according to claim 17, wherein the first polarization comprises horizontal polarization and wherein the second polarization comprises vertical polarization.

19. The OFDM transmitter method according to claim 17, wherein the first set of OFDM subcarriers are separated in frequency by a frequency spacing, and wherein the second set of OFDM subcarriers are also separated by the frequency spacing.

20. The OFDM transmitter method according to claim 17, wherein the first set of OFDM subcarriers are interleaved in at least one of frequency, time and polarization with the second set of OFDM subcarriers.

21. The OFDM transmitter method according to claim 17, wherein the data to be transmitted are multiplexed from a plurality of sources.

22. An Orthogonal Frequency Division Multiplexing (OFDM) receiver method, comprising:

receiving a first set of polarized OFDM subcarriers from a first antenna that exhibits a first polarization;

receiving a second set of polarized OFDM subcarriers from a second antenna that exhibits a second polarization; and

decoding the first and second sets of OFDM subcarriers into a stream of data,

wherein the first polarization is orthogonal to the second polarization.

23. The OFDM receiver method according to claim 22, wherein the first polarization comprises horizontal polarization and wherein the second polarization comprises vertical polarization.

24. The OFDM receiver method according to claim 22, wherein the first set of OFDM subcarriers are separated in frequency by a frequency spacing, and wherein the second set of OFDM subcarriers are also separated by the frequency spacing.

25. The OFDM receiver method according to claim 22, wherein the first set of OFDM subcarriers are interleaved in at least one of frequency, time and polarization with the second set of OFDM subcarriers.

26. The OFDM receiver method according to claim 22, further comprising demultiplexing the stream of data into a plurality data streams.