Multicarrier transmit diversity

• US 8,767,523 B1
• Filed: 07/22/2009
• Issued: 07/01/2014
• Est. Priority Date: 06/03/2002
• Status: Active Grant

• Current Assignee: Marvell Asia Pte Limited (Marvell Technology Group Limited)
• Original Assignee: Marvell International Limited (Marvell Technology Group Limited)
• Inventors: Narasimhan, Ravi
• Primary Examiner(s): NGUYEN, STEVEN H D
• Application Number:
  US12/507,418
• Time in Patent Office: 1,805 Days
• Field of Search: None
• US Class Current: 370/208
• CPC Class Codes: H04B 7/068 using space frequency diversity space-frequency coding H04L1/0606
• CPC Class Codes: H04L 1/0606 Space-frequency coding
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems

Abstract

Method, apparatus, and data packet format to implement transmit diversity in a multicarrier environment is disclosed. For diversity transmission operations, space frequency encoding techniques are employed creating distinguishable first and second time domain signals from a multicarrier frequency domain symbol bearing data of interest, which are then broadcast in parallel over first and second transmission units respectively. For diversity reception operations, complementary space frequency decoding is used to recover a corrected multicarrier frequency domain symbol from a time domain signal containing either this symbol, a space frequency modified symbol based on the multicarrier symbol, or a possible partial/complete combination of both. The data packet format includes portions defining a transmission diversity semaphore, a preamble enabling training of a receiver receiving the data packet, and a payload.

Claims

1. A diversity transmitter, comprising:

a symbol encoder configured to encode data in a multicarrier frequency domain symbol (MFDS);

a space frequency encoder responsive to said symbol encoder, said space frequency encoder configured to modify the MFDS to generate a modified MFDS in a first transmission mode;

a conversion unit responsive to said space frequency encoder, said conversion unit configured to convert the MFDS and the modified MFDS into first time domain counterparts, respectively, in the first transmission mode, and convert the MFDS into a second time domain counterpart in a second transmission mode;

an RF transmission unit responsive to the conversion unit, said RF transmission unit configured to transmit the first time domain counterparts in the first transmission mode and transmit the second time domain counterpart in the second transmission mode; and

a controller configured to control operation of the diversity transmitter to one of a plurality of transmission modes comprising the first transmission mode and the second transmission mode, wherein the first transmission mode is a diversity mode and the second transmission mode is a legacy mode.

2. The diversity transmitter of claim 1, wherein the MFDS comprises an orthogonal frequency division multiplexing (OFDM) encoded symbol.

3. The diversity transmitter of claim 2, wherein the OFDM encoded symbol is encoded in compliance with at least one of IEEE Standard 802.11a and IEEE Standard 802.11g supplements to the IEEE Standard 802.11 (1999).

4. The diversity transmitter of claim 1, wherein the modified MFDS comprises at least in part a re-ordered subcarrier complex conjugate of the MFDS.

5. The diversity transmitter of claim 1, wherein said conversion unit comprises:

a first conversion unit configured to convert the MFDS into one of the first time domain counterparts corresponding thereto in the first transmission mode; and

a second conversion unit configured to convert the modified MFDS into another one of the first time domain counterparts corresponding thereto in the first transmission mode.

6. The diversity transmitter of claim 1, wherein the RF transmission unit comprises:

a first RF transmission unit comprising an RF upconverter to modulate one of the first time domain counterparts of the MFDS onto a first carrier signal in the first transmission mode; and

a second RF transmission unit comprising an RF upconverter to modulate another one of the first time domain counterparts of the modified MFDS onto a second carrier signal in the first transmission mode,

wherein the first and second carrier signals operate in a common frequency channel.

7. A diversity aware receiver, comprising:

a controller configured to control operation of the diversity aware receiver to one of a plurality of reception modes comprising a first reception mode and a second reception mode, wherein the first reception mode is a diversity mode and the second reception mode is a legacy mode;

an RF receiver configured to receive a first time domain signal capable of defining a multicarrier frequency domain symbol (MFDS) and a modified MFDS in the first reception mode, and receive a second time domain signal capable of defining the MFDS in the second reception mode;

a conversion unit responsive to said RF receiver and configured to generate a first composite signal based on the first time domain signal in the first reception mode and generate a second composite signal based on the second time domain signal in the second reception mode, the first composite signal including at least an incomplete analog sum of the MFDS and the modified MFDS; and

a space frequency decoder responsive to said conversion unit and configured to decode the first composite signal in order to recover the MFDS in the first reception mode, and decode the second composite signal in order to recover the MFDS from the second composite signal in the second reception mode.

8. The diversity aware receiver of claim 7, wherein the MFDS comprises an orthogonal frequency division multiplexing (OFDM) encoded symbol.

9. The diversity aware receiver of claim 8, wherein the OFDM encoded symbol is encoded in compliance with at least one of IEEE Standard 802.11a and IEEE Standard 802.11g supplements to the IEEE Standard 802.11 (1999).

10. The diversity aware receiver of claim 7, wherein the modified MFDS comprises at least in part a re-ordered subcarrier complex conjugate of the MFDS.

11. A diversity transceiver, comprising:

a receiver; and

a transmitter, comprising;

a first control logic configured to control operation of the transmitter to one of a plurality of transmission modes comprising a first transmission mode and a second transmission mode;

a symbol encoder to encode data in a first multicarrier frequency domain symbol (MFDS);

a space frequency encoder responsive to said symbol encoder, said space frequency encoder configured to modify the first MFDS to generate a modified first MFDS in the first transmission mode;

a conversion unit responsive to said space frequency encoder, said conversion unit configured to

convert the first MFDS and the modified first MFDS into first time domain counterparts respectively corresponding thereto in the first transmission mode, and

convert the first MFDS into a second time domain counterpart corresponding thereto in the second transmission mode; and

an RF transmission unit responsive to the conversion unit and configured to

transmit the first time domain counterparts in the first transmission mode and transmit the second time domain counterpart in the second transmission mode, wherein the first transmission mode is a diversity mode and the second transmission mode is a legacy mode.

12. The diversity transceiver of claim 11, wherein said receiver comprises:

a second control logic configured to control operation of the receiver to one of a plurality of reception modes comprising a first reception mode and a second reception mode, wherein the first reception mode is a diversity mode and the second reception mode is a legacy mode;

an RF receiver configured to receive a first time domain signal in the first reception mode and receive a second time domain signal in the second reception mode, the first time domain signal defining a second MFDS and a modified second MFDS, and the second time domain signal defining the second MFDS;

a second conversion unit responsive to said RF receiver and configured to generate a first composite signal based on the first time domain signal in the first reception mode and generate a second composite signal based on the second time domain signal in the second reception mode, the first composite signal including at least an incomplete analog sum of the second MFDS and the modified second MFDS;

a space frequency decoder responsive to said second conversion unit and configured to recover the second MFDS from the first composite signal in the first reception mode and recover the second MFDS from the second composite signal in the second reception mode.

13. The diversity transceiver of claim 12, wherein the OFDM encoded symbol is encoded in compliance with at least one of IEEE Standard 802.11a and IEEE Standard 802.11g supplements to the IEEE Standard 802.11 (1999).

14. The diversity transceiver of claim 12, wherein the modified first MFDS comprises at least in part a re-ordered subcarrier complex conjugate of the first MFDS, and the modified second MFDS comprises a re-ordered subcarrier complex conjugate of the second MFDS.

15. A transmit diversity communication method, comprising:

controlling a transmission operation to one of a plurality of transmission modes comprising at least a first transmission mode and a second transmission mode;

encoding data in a first multicarrier frequency domain symbol (MFDS);

modifying the MFDS when operating in the first transmission mode;

converting the MFDS and the modified MFDS into first time domain counterparts respectively corresponding thereto when operating in the first transmission mode;

converting the MFDS into a second time domain counterpart corresponding thereto when operating in the second transmission mode;

transmitting the first time domain counterparts when operating in the first transmission mode, wherein the first transmission mode is a diversity mode; and

transmitting the second time domain counterpart when operating in the second transmission mode, wherein the second transmission mode is a legacy mode.

16. The method of claim 15, further comprising:

receiving one of the first time domain counterparts and the second time domain counterpart;

controlling a receiving operation to one of a plurality of reception modes comprising at least a first reception mode and a second reception mode;

generating a first composite signal based on the first time domain counterparts in the first reception mode, the first composite signal including at least an incomplete analog sum of the MFDS and the modified MFDS;

generating a second composite signal based on the second time domain counterpart in the second reception mode; and

recovering the MFDS from the first composite signal in the first reception mode; and

recovering the MFDS from the second composite signal in the second reception mode.

17. The method of claim 16, wherein the MFDS comprises an orthogonal frequency division multiplexing (OFDM) encoded symbol.

18. The method of claim 17, wherein the OFDM encoded symbol is encoded in compliance with at least one of IEEE Standard 802.11a and IEEE Standard 802.11g supplements to the IEEE Standard 802.11 (1999).

19. The method of claim 16, wherein the modified MFDS comprises at least in part a re-ordered subcarrier complex conjugate of the MFDS.