A network device for generating an expanded long training sequence with a minimal peak-to-average ratio. The network device includes a signal generating circuit for generating the expanded long training sequence. The network device also includes an inverse fourier Transform for processing the expanded long training sequence from the signal generating circuit and producing an optimal expanded long training sequence with a minimal peak-to-average ratio. The expanded long training sequence and the optimal expanded long training sequence are stored on more than 52 sub-carriers.
|
0. 21. A wireless communications device, comprising:
a signal generator that generates an extended long training sequence; and
an inverse fourier transformer operatively coupled to the signal generator,
wherein the inverse fourier transformer processes the extended long training sequence from the signal generator and provides an optimal extended long training sequence with a minimal peak-to-average ratio, and
wherein at least the optimal extended long training sequence is carried by a greater number of subcarriers than a standard wireless networking configuration for an orthogonal frequency division multiplexing scheme, and
wherein the optimal extended long training sequence is carried by exactly 56 active sub-carriers.
0. 1. A wireless communications device, comprising:
a signal generator that generates an extended long training sequence; and
an inverse fourier transformer operatively coupled to the signal generator,
wherein the inverse fourier transformer processes the extended long training sequence from the signal generator and provides an optimal extended long training sequence with a minimal peak-to-average ratio, and
wherein at least the optimal extended long training sequence is carried by a greater number of subcarriers than a standard wireless networking configuration for an orthogonal frequency division multiplexing scheme.
0. 2. The wireless communications device according to
0. 3. The wireless communications device according to
0. 4. The wireless communications device according to
0. 5. The wireless communications device according to
0. 6. The wireless communications device according to
0. 7. The wireless communications device according to
0. 8. The wireless communications device according to
0. 9. The wireless communications device according to
0. 10. The wireless communications device according to
0. 11. The wireless communications device according to
0. 12. The wireless communications device according to
0. 13. The wireless communications device according to
0. 14. The wireless communications device according to
0. 15. The wireless communications device according to
0. 16. The wireless communications device according to
0. 17. The wireless communications device according to
0. 18. The wireless communications device according to
0. 19. The wireless communications device according to
0. 20. The wireless communications device according to
a symbol mapper operatively coupled to the signal generator, wherein the symbol mapper receives coded bits and generates symbols for each of 64 subcarriers of an orthogonal frequency division multiplexing sequence.
0. 22. The wireless communications device according to claim 21, wherein the optimal extended long training sequence has a minimum peak-to-average power ratio of 3.6 dB.
0. 23. The wireless communications device according to claim 21, wherein a binary phase shift key encoding is used for each sub-carrier above the +26 indexed sub-carrier and below the −26 indexed sub-carrier.
0. 24. The wireless communications device according to claim 21, wherein the inverse fourier transformer comprises an inverse Fast fourier transformer or an inverse Discrete fourier transformer.
0. 25. The wireless communications device according to claim 21, wherein the wireless communications device comprises one or more of the following: a personal digital assistant, a laptop computer, a personal computer, a processor, and a cellular phone.
0. 26. The wireless communications device according to claim 21, wherein the wireless communications device comprises a wireless mobile communications device.
0. 27. The wireless communications device according to claim 21, wherein the wireless communications device comprises one or more of the following: an access point and a base station.
0. 28. The wireless communications device according to claim 21, wherein the wireless communications device is backwards compatible with legacy wireless local area network devices.
0. 29. The wireless communications device according to claim 21, wherein the optimal extended long training sequence is longer than a long training sequence used by a legacy wireless local area network device in accordance with a legacy wireless networking protocol standard.
0. 30. The wireless communications device according to claim 29, wherein the legacy wireless local area network device uses the optimal extended long training sequence to estimate a carrier frequency offset even though the optimal extended long training sequence is longer than the long training sequence that is specified by the legacy wireless networking protocol standard.
0. 31. The wireless communications device according to claim 30, wherein the long training sequence that is specified by the legacy wireless networking protocol standard is maintained in the extended long training sequence or the optimal extended long training sequence.
0. 32. The wireless communications device according to claim 29, wherein the legacy wireless networking protocol standard for the orthogonal frequency division multiplexing scheme corresponds to exactly 52 active subcarriers.
0. 33. The wireless communications device according to claim 32, wherein, for a long training sequence of the legacy wireless networking protocol standard, the indexed sub-carrier 0 is set to zero and encodings for the indexed sub-carriers −26 to +26 excluding the indexed sub-carrier 0 are:
0. 34. The wireless communications device according to claim 33, wherein:
the inverse fourier transformer comprises an inverse Fast fourier transformer or an inverse Discrete fourier transformer;
the wireless communications device comprises one or more of the following: a personal digital assistant, a laptop computer, a personal computer, a cellular phone, an access point, a processor, and a base station;
the wireless communications device is backwards compatible with the legacy wireless local area network device;
the legacy wireless local area network device uses the optimal extended long training sequence to estimate a carrier frequency offset even though the optimal extended long training sequence is longer than the long training sequence that is specified by the legacy wireless networking protocol standard;
the wireless communications device decreases power back-off;
the extended long training sequence or the optimal extended long training sequence is encoded using binary phase shift key encoding on each of the 56 active subcarriers; and
the wireless communications device further comprises a symbol mapper operatively coupled to the signal generator, wherein the symbol mapper receives coded bits and generates symbols for each of 64 subcarriers of an orthogonal frequency division multiplexing sequence.
0. 35. The wireless communications device according to claim 21, wherein the wireless communications device decreases power back-off.
0. 36. The wireless communications device according to claim 21, wherein the wireless communications device registers with one or more of the following: an access point and a base station.
0. 37. The wireless communications device according to claim 21, wherein the extended long training sequence or the optimal extended long training sequence is encoded using binary phase shift key encoding on each of the 56 active subcarriers.
0. 38. The wireless communications device according to claim 21, comprising:
a symbol mapper operatively coupled to the signal generator, wherein the symbol mapper receives coded bits and generates symbols for each of 64 subcarriers of an orthogonal frequency division multiplexing sequence.
0. 39. The wireless communications device according to claim 21, wherein at least one output of the inverse fourier transformer is operatively coupled to at least one digital-to-analog converter.
0. 40. The wireless communications device according to claim 21, wherein at least one output of the inverse fourier transformer is operatively coupled to multiple digital-to-analog converters.
0. 41. The wireless communications device according to claim 21, wherein an input of the signal generator is operatively coupled to a frequency-domain windower.
0. 42. The wireless communications device according to claim 21, wherein an output of the inverse fourier transformer is operatively coupled to a time-domain windower.
0. 43. The wireless communications device according to claim 42, wherein an output of the time-domain windower is operatively coupled to at least one digital-to-analog converter.
0. 44. The wireless communication device according to claim 21, wherein an output of the inverse fourier transformer is operatively coupled to a digital transmit filter.
0. 45. The wireless communications device according to claim 21, wherein an output of the inverse fourier transformer is operatively coupled to a parallel-to-serial convertor.
0. 46. The wireless communications device according to claim 21, wherein the optimal extended long training sequence is represented by encodings for indexed sub-carriers −28 to +28, excluding indexed sub-carrier 0 which is set to zero.
0. 47. The wireless communications device according to claim 21, wherein the wireless communications device is configured to convert parallel frequency-domain signals into serial time-domain signals.
|
utilized utilizes the same +1 or −1 binary phase shift key (BPSK) encoding for each new sub-carrier and the long training sequence of 802.11a or 802.11g systems is maintained in the present invention.
In a first embodiment of the invention, the expanded long training sequence is implemented in 56 active sub-carriers including sub-carriers −28 to +28 except the 0-index sub-carrier which is set to 0. In another embodiment, an expanded long training sequence is implemented using 63 active sub-carriers, i.e., all of the active sub-carriers (−32 to +31) except the 0-index sub-carrier which is set to 0. In both embodiments of the invention, orthogonality is not affected, since a 64-point orthogonal transform is used to generate the time-domain sequence. Additionally, the output of an auto-correlator for computing the carrier frequency offset is not affected by the extra sub-carriers.
It should be appreciated by one skilled in art, that the present invention may be utilized in any device that implements the OFDM encoding scheme. The foregoing description has been directed to specific embodiments of this invention. It will be apparent, however, that other variations and modifications may be made to the described embodiments, with the attainment of some or all of their advantages. Therefore, it is the object of the appended claims to cover all such variations and modifications as come within the true spirit and scope of the invention.
Trachewsky, Jason Alexander, Moorti, Rajendra T.
Patent | Priority | Assignee | Title |
Patent | Priority | Assignee | Title |
5479444, | Mar 09 1993 | Nokia Mobile Phones LTD | Training sequence in digital cellular radio telephone system |
5914933, | Mar 08 1996 | THE CHASE MANHATTAN BANK, AS COLLATERAL AGENT | Clustered OFDM communication system |
6438173, | Aug 05 1997 | LANTIQ BETEILIGUNGS-GMBH & CO KG | Multicarrier transmission system for irregular transmission of data blocks |
6696941, | Sep 04 2001 | Bell Northern Research, LLC | Theft alarm in mobile device |
6858930, | Oct 07 2002 | Bell Northern Research, LLC | Multi chip module |
6941156, | Jun 26 2001 | Bell Northern Research, LLC | Automatic handoff for wireless piconet multimode cell phone |
6963129, | Jun 18 2003 | Bell Northern Research, LLC | Multi-chip package having a contiguous heat spreader assembly |
7039435, | Sep 28 2001 | Bell Northern Research, LLC | Proximity regulation system for use with a portable cell phone and a method of operation thereof |
7203245, | Mar 31 2003 | Hewlett Packard Enterprise Development LP | Symbol boundary detector method and device for OFDM systems |
7254171, | Jan 20 2000 | Apple Inc | Equaliser for digital communications systems and method of equalisation |
7318185, | Aug 23 2001 | Apple Inc | Method and apparatus for scrambling based peak-to-average power ratio reduction without side information |
7319889, | Jun 17 2003 | Bell Northern Research, LLC | System and method for conserving battery power in a mobile station |
7324605, | Jan 12 2004 | SPREADTRUM COMMUNICATIONS SHANGHAI CO , LTD | High-throughput multicarrier communication systems and methods for exchanging channel state information |
7349436, | Sep 30 2003 | Intel Corporation | Systems and methods for high-throughput wideband wireless local area network communications |
7392015, | Feb 14 2003 | CALLAHAN CELLULAR L L C | Calibration methods and structures in wireless communications systems |
7394865, | Jun 25 2003 | Intellectual Ventures I LLC | Signal constellations for multi-carrier systems |
7433418, | Sep 28 2001 | Apple Inc | Method and apparatus for efficient storage of training sequences for peak to average power constrained modulation formats |
7444134, | Feb 13 2004 | AVAGO TECHNOLOGIES INTERNATIONAL SALES PTE LIMITED | Device and method for transmitting long training sequence for wireless communications |
7453793, | Apr 10 2003 | Qualcomm Incorporated | Channel estimation for OFDM communication systems including IEEE 802.11A and extended rate systems |
7539260, | May 27 2004 | Qualcomm Incorporated | Detecting the number of transmit antennas in wireless communication systems |
7564914, | Dec 14 2004 | Bell Northern Research, LLC | Method and system for frame formats for MIMO channel measurement exchange |
7599332, | Apr 05 2004 | Qualcomm Incorporated | Modified preamble structure for IEEE 802.11a extensions to allow for coexistence and interoperability between 802.11a devices and higher data rate, MIMO or otherwise extended devices |
7646703, | Jul 27 2004 | Bell Northern Research, LLC | Backward-compatible long training sequences for wireless communication networks |
7742388, | Jul 20 2004 | FLEET CONNECT SOLUTIONS LLC | Packet generation systems and methods |
7957450, | Dec 14 2004 | Bell Northern Research, LLC | Method and system for frame formats for MIMO channel measurement exchange |
7990842, | Jul 27 2004 | Bell Northern Research, LLC | Backward-compatible long training sequences for wireless communication networks |
8204554, | Jun 17 2003 | Bell Northern Research, LLC | System and method for conserving battery power in a mobile station |
8396072, | Feb 21 2011 | Bell Northern Research, LLC | Method and apparatus for channel traffic congestion avoidance in a mobile communication system |
8416862, | Apr 21 2005 | Bell Northern Research, LLC | Efficient feedback of channel information in a closed loop beamforming wireless communication system |
8457232, | May 27 2004 | Qualcomm Incorporated | Detecting the number of transmit antennas in wireless communication systems |
8477594, | Jul 27 2004 | Bell Northern Research, LLC | Backward-compatible long training sequences for wireless communication networks |
8792432, | Feb 14 2011 | Bell Northern Research, LLC | Prioritizing RACH message contents |
20030043887, | |||
20040008803, | |||
20040093545, | |||
20040264585, | |||
20050233709, | |||
20050265219, | |||
20050286474, | |||
20060002361, | |||
20060120447, | |||
20060209890, | |||
20060209892, | |||
20070002749, | |||
20070047671, | |||
20070060073, | |||
20100110876, | |||
RE48629, | Jul 27 2004 | Bell Northern Research, LLC | Backward-compatible long training sequences for wireless communication networks |
WO2004030265, |
Executed on | Assignor | Assignee | Conveyance | Frame | Reel | Doc |
Jul 06 2021 | Bell Northern Research, LLC | (assignment on the face of the patent) | / |
Date | Maintenance Fee Events |
Jul 06 2021 | BIG: Entity status set to Undiscounted (note the period is included in the code). |
Date | Maintenance Schedule |
Apr 25 2026 | 4 years fee payment window open |
Oct 25 2026 | 6 months grace period start (w surcharge) |
Apr 25 2027 | patent expiry (for year 4) |
Apr 25 2029 | 2 years to revive unintentionally abandoned end. (for year 4) |
Apr 25 2030 | 8 years fee payment window open |
Oct 25 2030 | 6 months grace period start (w surcharge) |
Apr 25 2031 | patent expiry (for year 8) |
Apr 25 2033 | 2 years to revive unintentionally abandoned end. (for year 8) |
Apr 25 2034 | 12 years fee payment window open |
Oct 25 2034 | 6 months grace period start (w surcharge) |
Apr 25 2035 | patent expiry (for year 12) |
Apr 25 2037 | 2 years to revive unintentionally abandoned end. (for year 12) |