Systems and methods for generating preamble symbols in communication systems

• US 9,480,104 B2
• Filed: 01/30/2013
• Issued: 10/25/2016
• Est. Priority Date: 01/30/2012
• Status: Active Grant

• Current Assignee: Marvell Asia Pte Limited (Marvell Technology Group Limited)
• Original Assignee: Marvell World Trade Limited (Marvell Technology Group Limited)
• Inventors: Zhang, Hongyuan, Srinivasa, Sudhir
• Primary Examiner(s): Phillips, Hassan
• Assistant Examiner(s): GEORGE, AYANAH S
• Application Number:
  US13/753,752
• Publication Number:
  US 20130195092A1
• Time in Patent Office: 1,364 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: H04L 27/2613 Structure of the reference signals
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

A method for transmitting an 802.11ah packet is provided. A training field sequence is generated using control circuitry. A preamble for a packet is generated using the control circuitry. The preamble includes a training field symbol which includes the training field sequence. A portion of the training field sequence is within a plurality of guard tones of the training field symbol. The preamble is transmitted using transmit circuitry.

Claims

1. A method for transmitting a wireless packet, the method comprising:

generating, using control circuitry, a training field sequence;

generating, using the control circuitry, a preamble for a packet, wherein the preamble comprises a first training field symbol, wherein the first training field symbol comprises the training field sequence, wherein respective portions of the training field sequence are located at respective guard tone locations at both ends of the first training field symbol; and

transmitting, using transmit circuitry, the preamble, wherein the transmitting comprises transmitting tones of the first training field symbol with the same frequency domain power per tone as tones of a second training field symbol.

2. The method of claim 1, wherein the portion of the training field sequence located at the guard tone location of the first training field symbol is non-zero.

3. The method of claim 1, wherein the training field sequence is based on repetitions of a training field sequence substantially similar to that of a baseline bandwidth.

4. The method of claim 3, wherein the training field sequence of the baseline bandwidth comprises a bit sequence of {1, 1, LTF_left, 0, LTF_right, −

1, −

1}, wherein LTF_left and LTF_right are predetermined training field bit sequences.

5. The method of claim 3, wherein the baseline bandwidth is 2 MHz.

6. The method of claim 3, wherein generating the preamble for the packet comprises generating the preamble for a bandwidth greater than baseline bandwidth.

7. The method of claim 1, wherein the first and second training field symbols are within the packet.

8. The method of claim 1, wherein the second training field symbol comprises a second training field sequence bounded by guard tones of the second training field symbol.

9. A system for transmitting a wireless packet, the system comprising:

preamble circuitry configured to

(i) generate a training field sequence,

(ii) generate a preamble for a packet, wherein the preamble comprises a first training field symbol, wherein the first training field symbol comprises the training field sequence, wherein respective portions of the training field sequence are located at respective guard tone locations at both ends of the first training field symbol, and

(iii) provide the preamble for transmission, wherein the system comprises transmit circuitry configured to transmit tones of the first training field symbol with the same frequency domain power per tone as tones of a second training field symbol.

10. The system of claim 9, wherein the portion of the training field sequence located at the guard tone location of the first training field symbol is non-zero.

11. The system of claim 9, wherein the training field sequence is based on substantially similar repetitions of a training field sequence of a baseline bandwidth.

12. The system of claim 11, wherein the training field sequence of the baseline bandwidth comprises a bit sequence of {1, 1, LTF_left, 0, LTF_right, −

1, −

1}, wherein LTF_left and LTF_right are predetermined training field bit sequences.

13. The system of claim 11, wherein the baseline bandwidth is 2 MHz.

14. The system of claim 11, wherein the preamble circuitry is configured to generate the preamble for a bandwidth greater than the baseline bandwidth.

15. The system of claim 9, wherein the first and second training field symbols are within the packet.

16. The system of claim 9, wherein the second training field symbol comprises a second training field sequence bounded by guard tones of the second training field symbol.