Method and apparatus for varying the number of pilot tones in a multiple antenna communication system
View Patent ↗Methods and apparatus are provided for varying the number of pilot tones in a multiple antenna communication system. Data is transmitted in a multiple antenna communication system by selecting a number of pilot tones to be employed to transmit the data; and transmitting an indication of the selected number of pilot tones in a preamble of a packet containing the data. Data is received in a multiple antenna communication system by receiving a preamble having an indication of a number of pilot tones embedded in the data; and processing the received data based on the indicated number of pilot tones. The indication of the selected number of pilot tones can be transmitted, for example, in a SIGNAL field of an exemplary IEEE 802.11 preamble. The number of pilot tones can be selected, for example, based on one or more of (i) a delay spread of a channel; (ii) the SNR at the receiver; or (iii) a number of antennas at a receiver.
1. A method for transmitting data in a multiple antenna communication system, said method comprising the step of:
selecting a number of pilot tones to be employed to transmit said data; and
transmitting an indication of a quantity of said selected number of pilot tones in a preamble of a packet containing said data.
2. The method of claim 1 , wherein said indication of said selected number of pilot tones is transmitted in a SIGNAL field.
3. The method of claim 1 , wherein said preamble is an IEEE 802.11 preamble.
4. The method of claim 1 , wherein said number of pilot tones is selected based on a delay spread of a channel.
5. The method of claim 1 , wherein said number of pilot tones is selected based on the SNR at the receiver.
6. The method of claim 1 , wherein said number of pilot tones is selected based on a number of antennas at a receiver.
7. A transmitter in a multiple antenna communication system, comprising:
a memory; and
at least one processor, coupled to the memory, operative to:
select a number of pilot tones to be employed to transmit said data: and
transmit an indication of a quantity of said selected number of pilot tones in a preamble of a packet containing said data.
8. The transmitter of claim 7 , wherein said indication of said selected number of pilot tones is transmitted in a SIGNAL field.
9. The transmitter of claim 7 , wherein said preamble is an IEEE 802.11 preamble.
10. The transmitter of claim 7 , wherein said processor is further con figured to select said number of pilot tones based on a delay spread of a channel.
11. The transmitter of claim 7 , wherein said processor is further configured to select said number of pilot tones based on the SNR at the receiver.
12. The transmitter of claim 7 wherein said processor is further configured to select said number of pilot tones based on a number of antennas at a receiver.
13. A method for receiving data in a multiple antenna communication system, said method comprising the steps of:
receiving a preamble having an indication of a quantity of pilot tones embedded in said data; and
processing said received data based on said indicated number of pilot tones.
14. The method of claim 13 , wherein said indication of said selected number of pilot tones is transmitted in a SIGNAL field.
15. The method of claim 13 , wherein said preamble is an IEEE 802.11 preamble.
16. The method of claim 13 , wherein said number of pilot tones is selected based on one or more of (i) a delay spread of a channel: (ii) the SNR at the receiver; or (iii) a number of antennas at a receiver.
17. A receiver in a multiple antenna communication system, comprising:
at least one receiver antenna for receiving a preamble having an indication of a quantity of pilot tones embedded in said data; and
means for processing said received data based on said indicated number of pilot tones.
18. The receiver of claim 17 , wherein said indication of said number of pilot tones is transmitted in a SIGNAL field.
19. The receiver of claim 17 , wherein said preamble is an IEEE 802.11 preamble.
20. The receiver of claim 17 , wherein said number of pilot tones is selected based on one or more of (i) a delay spread of a channel; (ii) the SNR at the receiver; or (iii) a number of antennas at said receiver.