Case 1:22-cv-22706-RNS Document 1-20 Entered on FLSD Docket 08/25/2022 Page 1 of 12
`
`EXHIBIT C
`
`

`

`( 19 ) United States
`( 12 ) Reissued Patent
`Trachewsky et al .
`
`( 54 ) BACKWARD - COMPATIBLE LONG
`TRAINING SEQUENCES FOR WIRELESS
`COMMUNICATION NETWORKS
`( 71 ) Applicant : Bell Northern Research , LLC ,
`Chicago , IL ( US )
`( 72 ) Inventors : Jason Alexander Trachewsky , Menlo
`Park , CA ( US ) ; Rajendra T. Moorti ,
`Mountain View , CA ( US )
`( 73 ) Assignee : Bell Northern Research , LLC ,
`Chicago , IL ( US )
`( 21 ) Appl . No .: 16 / 686,468
`( 22 ) Filed :
`Nov. 18 , 2019
`Related U.S. Patent Documents
`
`7,990,842
`Aug. 2 , 2011
`12 / 684,650
`Jan. 8 , 2010
`
`Reissue of :
`( 64 ) Patent No .:
`Issued :
`Appl . No .:
`Filed :
`U.S. Applications :
`( 63 ) Continuation of application No. 11 / 188,771 , filed on
`Jul . 26 , 2005 , now Pat . No. 7,646,703 .
`( 60 ) Provisional application No. 60 / 634,102 , filed on Dec.
`8 , 2004 , provisional application No. 60 / 591,104 , filed
`on Jul . 27 , 2004 .
`( 51 ) Int . Cl .
`H04L 27/26
`H04L 5/00
`H04L 25/02
`( 52 ) U.S. CI .
`H04L 27/2613 ( 2013.01 ) ; H04L 27/262
`CPC
`( 2013.01 ) ; H04B 2201/70701 ( 2013.01 ) ; H04B
`2201/70706 ( 2013.01 ) ; H04L 5/0048
`( 2013.01 ) ; H04L 25/0226 ( 2013.01 )
`
`( 2006.01 )
`( 2006.01 )
`( 2006.01 )
`
`USOORE48629E
`
`US RE48,629 E
`( 10 ) Patent Number :
`( 45 ) Date of Reissued Patent :
`Jul . 6 , 2021
`
`( 56 )
`
`( 58 ) Field of Classification Search
`CPC . HO4L 27/2613 ; H04L 27/262 ; H04L 5/0048 ;
`H04L 25/0226 ; H04B 2201/70701 ; H04B
`2201/70706
`See application file for complete search history .
`References Cited
`U.S. PATENT DOCUMENTS
`12/1995 Malkamaki et al .
`5,479,444 A
`5,914,933 A
`6/1999 Cimini et al .
`( Continued )
`FOREIGN PATENT DOCUMENTS
`
`WO
`
`WO2004030265 Al
`
`4/2004
`
`OTHER PUBLICATIONS
`“ Part 11 : Wireless LAN Medium Access Control ( MAC ) and
`Physical Layer ( PHY ) specifications : High - speed Physical Layer in
`the 5 GHZ Band , ” IEEE Std 802.11a - 1999 ( Supplement to IEEE
`Std 802.11-1999 ) , Dec. 30 , 1999 , pp . 1-90 , IEEE , United States .
`( Continued )
`Primary Examiner Mark Sager
`( 74 ) Attorney , Agent , or Firm Mendelsohn Dunleavy ,
`P.C .; Steve Mendelsohn
`( 57 )
`ABSTRACT
`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 .
`
`25 Claims , 5 Drawing Sheets
`
`Case 1:22-cv-22706-RNS Document 1-20 Entered on FLSD Docket 08/25/2022 Page 2 of 12
`
`Subcarrier
`-26
`
`Subcarrier
`-25
`
`Subcamer
`
`1
`
`Subcanter
`25
`
`Subcorder
`28
`
`Subcarrier
`26
`
`Subcarrier
`26
`
`Subcarrier
`-25
`
`212
`
`
`
`Coded Bits
`
`NON
`
`AON
`
`on ON
`
`206
`
`208
`
`210
`
`212
`
`212
`
`Subcarrier
`+26
`
`Subcarrier
`+26
`
`Subcamlar
`+25
`
`Subcamar
`+28
`
`Subcamier
`+25
`
`Subcasier
`+26
`
`Subcamper
`+25
`
`Subcarier
`+26
`
`200
`
`

`

`US RE48,629 E
`Page 2
`
`( 56 )
`
`References Cited
`U.S. PATENT DOCUMENTS
`6,438,173 B1
`8/2002 Stantchev
`9/2005 Mooney
`6,941,156 B2
`4/2007 Murphy
`7,203,245 B1
`7,254,171 B2
`8/2007 Hudson
`7,318,185 B2
`1/2008 Khandani et al .
`7,319,889 B2
`1/2008 Goris et al .
`1/2008 Maltsev et al .
`7,324,605 B2
`7,349,436 B2
`3/2008 Maltsev et al .
`7,392,015 B1
`6/2008 Farlow et al .
`7,394,865 B2
`7/2008 Borran et al .
`10/2008 Dogan et al .
`7,433,418 B1
`7,444,134 B2
`10/2008 Hansen et al .
`7,453,793 B1
`11/2008 Jones , IV et al .
`7,539,260 B2
`5/2009 van Zelst et al .
`7,599,332 B2
`10/2009 Zelst et al .
`1/2010 Trachewsky et al .
`7,646,703 B2
`6/2010 Shearer et al .
`7,742,388 B2
`8,204,554 B2
`6/2012 Goris et al .
`4/2013 Aldana et al .
`8,416,862 B2
`6/2013 van Zelst et al .
`8,457,232 B2
`7/2013 Trachewsky et al .
`8,477,594 B2
`7/2014 Martin et al .
`8,792,432 B2
`3/2003 Hudson
`2003/0043887 A1
`1/2004 Aldrovandi et al .
`2004/0008803 A1
`5/2004 Khandani et al .
`2004/0093545 A1
`2004/0264585 A1
`12/2004 Borran et al .
`2005/0233709 Al
`10/2005 Gardner et al .
`12/2005 Murphy et al .
`2005/0265219 Al
`2005/0286474 Al
`12/2005 van Zelst et al .
`1/2006 Webster et al .
`2006/0002361 Al
`6/2006 Trachewsky et al .
`2006/0120447 A1
`2006/0209890 A1
`9/2006 Mac Mullan et al .
`9/2006 MacMullan et al .
`2006/0209892 Al
`2007/0002749 Al
`1/2007 Sondur et al .
`
`2007/0047671 Al
`2007/0060073 A1
`2010/0110876 Al
`
`3/2007 Chen
`3/2007 Boer et al .
`5/2010 Trachewsky et al .
`
`OTHER PUBLICATIONS
`Ogawa , Yasutaka et al . “ A MIMO - OFDM System for High - Speed
`Transmission , ” 2003 IEEE 58th Vehicular Technology Conference ,
`Oct. 9 , 2003 , pp . 493-497 , IEEE , Orland , United States .
`Abhayawardhana , V. S. et al . , “ Frequency Scaled Time Domain
`Equalization for OFDM in Broadband Fixed Wireless Access Chan
`nels , ” 2002 IEEE Wireless Communications and Networking Con
`ference Record , Mar. 21 , 2002 , pp . 67-72 , IEEE , Orland , United
`States .
`Liebetreu , John et al . , “ Modifications to OFDM FFT - 256 mode for
`supporting mobile operation , ” IEEE C802.16e - 03 / 12 , Mar. 3 , 2003 ,
`pp . 0-8 , IEEE .
`Decision : Settlement Prior to Institution of Trial ; IPR 2019-01174 ;
`dated Dec. 11 , 2019 .
`Decision : Settlement Prior to Institution of Trial ; IPR 2019-01345 ;
`dated Dec. 11 , 2019 .
`Decision : Settlement Prior to Institution of Trial ; IPR 2019-01437 ;
`dated Dec. 11 , 2019 .
`Order Granting Joint Motion for Dismissal as to Counts III and IV
`of BNR's Complaint and Partial Dismissal of Counts I and II of
`Coolpad's Counterclaims ; C.A. No. 3 : 18 - cv - 1783 - CAB - BLM ; dated
`Oct. 7 , 2019 .
`Order Granting Joint Morion to Dismiss ; Case No. 18 - CV - 1785
`CAB - BLM ; dated Aug. 5 , 2019 .
`Order Granting Joint Motion for Dismissal as to Counts 3 and 6 of
`BNR's Amended Complaint and Counts VI , VII , X , and XI of ZTE
`Corporation , ZTE ( TX ) , Inc. , and ZTE ( USA ) Inc.'s Counterclaims ;
`C.A. No. 3 : 18 - cv - 1786 - CAB - BLM ; dated Oct. 4 , 2019 .
`Order Granting Joint Motion for Dismissal as to Counts III and VI
`of BNR's Second Amended Complaint ; C.A. No. 3 : 18 - cv - 1784
`CAB - BLM ; dated Oct. 21 , 2019 .
`
`Case 1:22-cv-22706-RNS Document 1-20 Entered on FLSD Docket 08/25/2022 Page 3 of 12
`
`

`

`U.S. Patent
`
`Jul . 6 , 2021
`
`Sheet 1 of 5
`
`US RE48,629 E
`
`26
`
`30
`
`26
`
`Radioytower
`
`16
`
`34
`
`32
`
`Us
`
`Figure 1
`
`10
`
`20
`
`18
`
`12
`
`
`
`Radio tower
`
`Case 1:22-cv-22706-RNS Document 1-20 Entered on FLSD Docket 08/25/2022 Page 4 of 12
`
`14
`
`
`
`Radio tower !
`
`24
`
`?
`PADDALLARA .
`
`22
`
`TIT
`
`

`

`U.S. Patent
`
`Jul . 6 , 2021
`
`Sheet 2 of 5
`
`US RE48,629 E
`
`212
`
`212
`
`is
`
`212
`
`210
`
`208
`
`206
`
`an ON
`
`2 0 4
`
`.
`
`NON
`
`
`
`Coded Bits
`
`Subcarrier -26
`
`Subcarrier -25
`
`Subcarrier -26
`
`Subcarrier -25
`
`Subcarrier -26
`Subcarrier -26
`
`Subcarrier -25
`Subcarrier -25
`
`Figure 2
`
`200
`
`Subcarrier +25
`
`Subcarrier +26
`
`Subcarrier +25
`
`Subcarrier +25
`Subcarrier +25
`
`Subcarrier +26
`
`Subcarrier +26
`Subcarrier +26
`
`Case 1:22-cv-22706-RNS Document 1-20 Entered on FLSD Docket 08/25/2022 Page 5 of 12
`
`

`

`U.S. Patent
`
`Jul . 6 , 2021
`
`Sheet 3 of 5
`
`US RE48,629 E
`
`312
`
`312
`
`312
`
`310
`
`308
`
`306
`
`304
`
`302
`
`Bits
`
`Coded
`
`Subcarrier -26
`
`Subcarrier -23
`
`Subcarrier -26
`
`Subcarrier -23
`
`Subcarrier -26
`
`Subcarrier -23
`
`Figure 3
`
`300
`
`Subcarrier +23
`
`Subcarrier +26
`
`Subcarrier +23
`
`Subcarrier +26
`
`Subcarrier +23
`
`Subcarrier +26
`
`Case 1:22-cv-22706-RNS Document 1-20 Entered on FLSD Docket 08/25/2022 Page 6 of 12
`
`

`

`U.S. Patent
`
`Jul . 6 , 2021
`
`Sheet 4 of 5
`
`US RE48,629 E
`
`1 -15
`
`1 -16
`
`1 -17
`
`-1 -18
`
`1 -19
`
`-1 -20
`
`1 -21
`
`1 -22
`
`-1 -23
`
`-1 -24
`
`1 -25
`
`1 -26
`
`+1 -27
`
`+1 -28
`
`Case 1:22-cv-22706-RNS Document 1-20 Entered on FLSD Docket 08/25/2022 Page 7 of 12
`
`0 0
`
`1 -1
`
`1 -2
`
`1 -3
`
`1 -4
`
`-1 -5
`
`1 -6
`
`: - 1 -7
`
`1 -8
`
`1 -9
`
`-1 -10
`
`-1 -11
`
`1 -12
`
`1 -13
`
`1 -14
`
`
`
`Sub - carrier index
`
`-1 14
`
`- 1 13
`
`-1 12
`
`-1 11
`
`-1 10
`
`1 9
`
`-1 8
`
`1 7
`1
`
`-1 6
`
`1 5
`
`1 4
`
`-1 3
`
`-1 2
`
`-1 28
`
`-1 27
`
`1 26
`
`1 25
`
`1 24
`
`1 23
`
`22
`
`1 21
`
`-1 20
`
`19
`
`-1 18
`
`-1 17
`
`1 16
`
`
`
`Sub - carrier index
`
`
`
`
`
`LONG TRAINING SEQUENCE FOR 56 ACTIVE FIGURE 4
`
`
`
`Sub - carrier index
`
`
`
`Sub - carrier index
`
`+1 1
`
`1 15
`
`

`

`U.S. Patent
`
`Jul . 6 , 2021
`
`Sheet 5 of 5
`
`US RE48,629 E
`
`1 -15
`
`1 -16
`
`1 -17
`
`-1 -18
`
`1 -19
`
`-1 -20
`
`1 -21
`
`1 -22
`
`- 1 -23
`
`- 1 -24
`
`1 -25
`
`1 -26
`
`+1 -27
`
`+1 -28
`
`+1 -29
`
`+1 -30
`
`-1 -31
`
`-1 -32
`
`
`
`Sub - carrier index
`
`0 0
`
`1 -1
`
`1 -2
`
`1 -3
`
`-4
`
`1
`
`-1
`
`-6
`
`1
`
`-1 -7
`
`1 -8
`
`1
`
`-9
`
`-1 -10
`
`-1 -11
`
`1 -12
`
`1 -13
`
`1 -14
`
`Case 1:22-cv-22706-RNS Document 1-20 Entered on FLSD Docket 08/25/2022 Page 8 of 12
`
`-1 14
`
`-1 13
`
`-1 12
`
`-1 11
`
`-1
`
`10
`
`Stilo
`
`-1 8
`
`1 7
`
`-1 6
`
`1 5
`
`1 4
`
`- 1 3
`
`-1 2
`
`+1 1
`
`
`
`Sub - carrier index
`
`
`
`Sub - carrier index
`
`
`
`
`
`LONG TRAINING SEQUENCE FOR 63 ACTIVE FIGURE 5
`
`- 1 31
`
`+1 30
`
`-1 29
`
`-1 28
`
`-1 27
`
`1 26
`
`1 25
`
`1 24
`
`1 23
`
`-1 22
`
`1 21
`
`-1 20
`
`1 19
`
`-1 18
`
`-1 17
`
`1 16
`
`1 15
`
`
`
`Sub - carrier index
`
`

`

`US RE48,629 E
`
`1
`2
`developed to address , among other thins , higher throughput
`BACKWARD - COMPATIBLE LONG
`TRAINING SEQUENCES FOR WIRELESS
`and compatibility issues . An 802.11a compliant communi
`cations device may reside in the same WLAN as a device
`COMMUNICATION NETWORKS
`that is compliant with another 802.11 standard . When
`Matter enclosed in heavy brackets [ ] appears in the 5 devices that are compliant with multiple versions of the
`802.11 standard are in the same WLAN , the devices that are
`original patent but forms no part of this reissue specifica
`compliant with older versions are considered to be legacy
`tion ; matter printed in italics indicates the additions
`devices . To ensure backward compatibility with legacy
`made by reissue ; a claim printed with strikethrough
`devices , specific mechanisms must be employed to insure
`indicates that the claim was canceled , disclaimed , or held 10 that the legacy devices know when a device that is compliant
`invalid by a prior post - patent action or proceeding .
`with a newer version of the standard is using a wireless
`channel to avoid a collision . New implementations of wire
`CROSS - REFERENCE TO RELATED
`less communication protocol enable higher speed through
`APPLICATIONS
`15 put , while also enabling legacy devices which might be only
`compliant with 802.11a or 802.11g to communicate in
`The present application is a reissue application for U.S.
`systems which are operating at higher speeds .
`Pat . No. 7,990,842 , which was a CONTINUATION of U.S.
`application Ser . No. 11 / 188,771 , filed Jul . 26 , 2005 and
`Devices implementing both the 802.11a and 802.11g
`standards use an orthogonal frequency division multiplexing
`issued as U.S. Pat . No. 7,646,703 . Said U.S. application Ser .
`No. 11 / 188,771 makes reference to , claims priority to and 20 ( OFDM ) encoding scheme . OFDM is a frequency division
`claims benefit from U.S. Application No. 60 / 591,104 , filed
`multiplexing modulation technique for transmitting large
`Jul . 27 , 2004 ; and U.S. Application No. 60 / 634,102 , filed
`amounts of digital data over a radio wave . OFDM works by
`Dec. 8 , 2004. The above - identified applications are hereby
`spreading a single data stream ove a band of sub - carriers ,
`incorporated herein by reference in their entirety .
`each of which is transmitted in parallel . In 802.11a and
`25 802.11g compliant devices , only 52 of the 64 active sub
`carriers are used . Four of the active sub - carriers are pilot
`BACKGROUND OF THE INVENTION
`sub - carriers that the system uses as a reference to disregard
`frequency or phase shifts of the signal during transmission .
`1. Field of the Invention
`The present invention relates generally to wireless com-
`The remaining 48 sub - carriers provide separate wireless
`munication systems and more particularly to long training 30 pathways for sending information in a parallel fashion . The
`sequences of minimum peak - to - average power ratio which
`52 sub - carriers are modulated using binary or quadrature
`may be used by legacy systems .
`phase shift keying ( BPSK / QPSK ) , 16 Quadrature Amplitude
`2. Description of the Related Art
`Modulation ( QAM ) , or 64 QAM . Therefore , 802.11a and
`Each wireless communication device participating in
`802.11g compliant devices use sub - carriers -26 to +26 , with
`wireless communications includes a built - in radio trans- 35 the O - index sub - carrier set to 0 and 0 - index sub - carrier being
`ceiver ( i.e. , receiver and transmitter ) or is coupled to an
`the carrier frequency . As such , only part of the 20 Mhz
`associated radio transceiver . As is known to those skilled in
`bandwidth supported by 802.11a and 802.11g is use .
`the art , the transmitter typically includes a data modulation
`In 802.11a / 802.11g , each data packet starts with pre
`stage , one or more intermediate frequency stages , and a
`amble which includes a short training sequence followed by
`power amplifier . The data modulation stage converts raw 40 a long training sequence . The short and long training
`data into baseband signals in accordance with a particular
`sequences are used for synchronization between the sender
`wireless communication standard . The intermediate fre-
`and the receiver . The long training sequence of 802.11a and
`quency stages mix the baseband signals with one or more
`802.11g is defined such that each of sub - carriers -26 to +26 ,
`local oscillations to produce RF signals . The power amplifier
`except for the sub - carrier ( which is set to 0 , has one BPSK
`amplifies the RF signals prior to transmission via an antenna . 45 [ consellation ] constellation point , either +1 or -1 .
`The receiver is typically coupled to the antenna and
`There exists a need to create a long training sequence of
`includes a low noise amplifier , one or more intermediate
`minimum peak - to - average ratio that uses more sub - carriers
`frequency stages , a filtering stage , and a data recovery stage .
`without interfering with adjacent channels . The inventive
`The low noise amplifier receives , via the antenna , inbound
`long ?trains ] training sequence with a minimum peak - to
`RF signals and amplifies the inbound RF signals . The 50 average power ratio should be usable by legacy devices in
`intermediate frequency stages mix the amplified RF signals
`order to estimate channel impulse response and to estimate
`with one or more local oscillations to convert the amplified
`carrier frequency offset between a transmitter and a receiver .
`RF signal into baseband signals or intermediate frequency
`( IF ) signals . The filtering stage filters the baseband signals or
`SUMMARY OF THE INVENTION
`the IF signals to attenuate unwanted out of band signals to 55
`produce filtered signals . The data recovery stage recovers
`According to one aspect of the invention , there is pro
`raw data from the filtered signals in accordance with a
`vided a network device for generating an expanded long
`training sequence with a minimal peak - to - average ratio . The
`particular wireless communication standard .
`Different wireless devices in a wireless communication
`network device includes a signal generating circuit for
`system may be compliant with different standards or differ- 60 generating the expanded long training sequence . The net
`ent variations of the same standard . For example , 802.11a an
`work device also includes an Inverse Fourier Transform for
`extension of the 802.11 standard , provides up to 54 Mbps in
`processing the expanded long training sequence from the
`the 5 GHz band . 802.11b , another extension of the 802.11
`signal generating circuit and producing an optimal expanded
`standard , provides 11 Mbps transmission ( with a fallback to
`long training sequence with a minimal peak - to - average
`5.5 , 2 and 1 Mbps ) in the 2.4 GHz band . 802.11g , another 65 ratio . The expanded long training sequence and the optimal
`extension of the 802.11 standard , provides 20+ Mbps in the
`expanded long training sequence are stored on more than 52
`2.4 GHz band . 802.11n , a new extension of 802.11 , is being
`sub - carriers .
`
`Case 1:22-cv-22706-RNS Document 1-20 Entered on FLSD Docket 08/25/2022 Page 9 of 12
`
`

`

`US RE48,629 E
`
`5
`
`3
`4
`or access points 12-16 are operably coupled to network
`According to another aspect of the invention , there is
`hardware 34 via local area network connections 36 , 38 and
`provided a network device for generating an expanded long
`40. Network hardware 34 , for example a router , a switch , a
`training sequence with a minimal peak - to - average ratio . The
`bridge , a modem , or a system controller , provides a wide
`network device includes a signal generating circuit for
`area network connection for communication system 10 .
`generating the expanded long training sequence . The net
`Each of base stations or access points 12-16 has an associ
`work device also includes an Inverse Fourier Transform for
`ated antenna or antenna array to communicate with the
`processing the expanded long training sequence from the
`wireless communication devices in its area . Typically , the
`signal generating circuit and producing an optimal expanded
`wireless communication devices register with a particular
`long training sequence with a minimal peak - to - average
`ratio . The expanded long training sequence and the optimal 10 base station or access point 12-14 to receive services from
`expanded long training sequence are stored on more than 56
`communication system 10. Each wireless communication
`device includes a built - in radio or is coupled to an associated
`sub - carriers .
`According to another aspect of the invention , there is
`radio . The radio includes at least one radio frequency ( RF )
`transmitter and at least one RF receiver .
`provided a network device for generating an expanded long
`The present invention provides an expanded long training
`training sequence with a minimal peak - to - average ratio . The 15
`sequence of minimum peak - to - average power ratio and
`network device includes a signal generating circuit for
`thereby decreases power back - off . The inventive expanded
`generating the expanded long training sequence . The net
`work device also includes an Inverse Fourier Transform for
`long training sequence may be used by 802.11a or 802.11g
`devices for estimating the channel impulse response and by
`processing the expanded long training sequence from the
`signal generating circuit and producing an optimal expanded 20 a receiver for estimating the carrier frequency offset between
`long training sequence with a minimal peak - to - average
`the transmitter clock and receiver clock . The inventive
`ratio . The expanded long training sequence and the optimal
`expanded long training sequence is usable by 802.11a or
`802.11g systems only if the values at sub - carriers -26 to +26
`expanded long training sequence are stored on more than 63
`are identical to those of the current long training sequence
`sub - carriers .
`According to another aspect of the invention , there is 25 used in 802.11a and 802.11g systems . As such , the invention
`provided a method for generating an expanded long training
`[ utilized ] utilizes the same +1 or -1 binary phase shift key
`sequence with a minimal peak - to - average ratio . The method
`( BPSK ) encoding for each new sub - carrier and the long
`includes the steps of generating the expanded long training
`training sequence of 802.11a or 802.11g systems is main
`sequence and producing an optimal expanded long training
`tained in the present invention .
`sequence with a minimal peak - to - average ratio . The method 30
`In a first embodiment of the invention , the expanded long
`also includes the step of storing the expanded long training
`training sequence is implemented in 56 active sub - carriers
`sequence and the optimal expanded long training sequence
`including sub - carriers –28 to +28 except the 0 - index sub
`carrier which is set to 0. In another embodiment , an
`on more than 52 sub - carriers .
`expanded long training sequence is implemented using 63
`BRIEF DESCRIPTION OF THE DRAWINGS
`35 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
`The accompanying drawings , which are included to pro-
`embodiments of the invention , orthogonality is not affected ,
`since a 64 - point orthogonal transform is used to generate the
`vide a further understanding of the invention and are incor-
`porated in and constitute a part of this specification , illustrate
`time - domain sequence . Additionally , the output of an auto
`embodiments of the invention that together with the descrip- 40 correlator for computing the carrier frequency offset is not
`tion serve to explain the principles of the invention , wherein :
`affected by the extra sub - carriers .
`FIG . 2 illustrates a schematic block diagram of a proces
`FIG . 1 illustrates a communication system that includes a
`plurality of base stations , a plurality of wireless communi-
`sor that is configured to generate an expanded long training
`sequence . Processor 200 includes a symbol mapper 202 , a
`cation devices and a network hardware component ;
`FIG . 2 illustrates a schematic block diagram of a proces- 45 frequency domain window 204 , a signal generating circuit
`sor that is configured to generate an expanded long training
`205 , an inverse [ fast ] Fourier transform [ ( IFFT ) ] module
`206 , a [ serial to ] parallel to serial module 208 , a digital
`sequence ;
`FIG . 3 is a schematic block diagram of a processor that is
`transmit filter and / or time domain window module 210 , and
`configured to process an expanded long training sequence ;
`digital to analog converters ( D / A ) 212. For an expanded
`FIG . 4 illustrates the long training sequence that is used 50 long training sequence , symbol mapper 202 generates sym
`bols from the coded bits for each of the 64 subcarriers of an
`in 56 active sub - carriers ; and
`FIG . 5 illustrates the long training sequence that is used
`OFDM sequence . Frequency domain window 204 applies a
`weighting factor on each subcarrier . Signal generating cir
`in 63 active sub - carriers .
`cuit 205 generates the expanded long training sequence and
`55 if 56 active sub - carriers are being used , signal generating
`circuit generates the expanded long training sequence and
`stores the expanded long training sequence in sub - carriers
`-28 to +28 except the 0 - index sub - carrier which is set to 0 .
`Reference will now be made to the preferred embodi-
`If 63 active sub - carriers are being used , signal generating
`ments of the present invention , examples of which are
`illustrated in the accompanying drawings .
`60 circuit generates the expanded long training sequence and
`stores the expanded long training sequence in sub - carriers
`FIG . 1 illustrates a communication system 10 that
`-32 to +32 i.e. , all of the active sub - carriers ( -32 to +31 )
`includes a plurality of base stations and / or access points
`except the 0 - index sub - carrier which is set to 0. The inven
`12-16 , a plurality of wireless communication devices 18-32
`tive long training sequence is inputted into an Inverse
`and a network hardware component 34. Wireless commu-
`nication devices 18-32 may be laptop computers 18 and 26 , 65 Fourier Transform 206. The invention uses the same +1 or
`personal digital assistant hosts 20 and 30 , personal computer
`-1 BPSK encoding for each new sub - carrier . Inverse Fourier
`24 and 32 and / or cellular telephone 22 and 28. Base stations
`Transform 206 may be an inverse Fast Fourier Transform
`
`DETAILED DESCRIPTION OF THE
`INVENTION
`
`Case 1:22-cv-22706-RNS Document 1-20 Entered on FLSD Docket 08/25/2022 Page 10 of 12
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`

`

`-26
`+1
`-12
`+1
`3
`-1
`17
`-1
`
`-25
`+1
`-11
`-1
`4
`+1
`18
`-1
`
`-19
`+1
`-5
`-1
`10
`-1
`24
`+1
`
`-18
`-1
`-4
`+1
`11
`-1
`25
`+1
`
`-17
`+1
`-3
`+1
`12
`-1
`26
`+1
`
`-16
`+1
`-2
`+1
`13
`-1
`27
`-1
`
`US RE48,629 E
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`-27
`+1
`-13
`+1
`2
`-1
`16
`+1
`
`-20
`
`-6
`+1
`9
`+1
`23
`+1
`
`-21
`+1
`-7
`-1
`8
`-1
`22
`-1
`
`Case 1:22-cv-22706-RNS Document 1-20 Entered on FLSD Docket 08/25/2022 Page 11 of 12
`
`-24
`
`-10
`-1
`5
`+1
`19
`+1
`
`-23
`-1
`-9
`+1
`6
`-1
`20
`-1
`
`-22
`+1
`-8
`+1
`7
`+1
`21
`+1
`
`-15
`+1
`
`+1
`14
`-1
`28
`-1 .
`
`6
`wherein the optimal extended long training sequence is
`carried by exactly 56 active sub - carriers , and
`wherein the optimal extended long training sequence is
`represented by encodings for indexed sub - carriers -28
`to +28 , excluding indexed sub - carrier ( which is set to
`zero , as follows :
`-28
`Sub - carrier
`+1
`-14
`+1
`1
`+1
`15
`+1
`
`5
`( IFFT ) or Inverse Discrete Fourier Transform [ ( IFDT ) ]
`( IDF7 ) . Inverse Fourier Transform 206 processes the long
`training sequence from signal generating circuit 205 and
`thereafter produces an optimal expanded long training
`sequence with a minimal peak - to - average power ratio . The 5
`optimal expanded long training sequence may be used in
`either 56 active sub - carriers or 63 active subscribers . [ Serial
`to parallel ] Parallel to serial module 208 converts the
`[ serial ] parallel time domain signals from the Inverse Fou Encoding
`Sub - carrier
`rier Transform 206 into [ parallel ] serial time domain signals 10 Encoding
`that are subsequently filtered and converted to analog signals
`Sub - carrier
`Encoding
`via the D / A .
`Sub - carrier
`FIG . 3 is a schematic block diagram of a processor that is
`Encoding
`configured to process an expanded long training sequence .
`Processor 300 includes a symbol demapper 302 , a frequency 15 Sub - carrier
`Encoding
`domain window 304 , a fast Fourier transform ( FFT ) module
`Sub - carrier
`306 , a [ parallel to ] serial to parallel module 308 , a digital
`Encoding
`receiver filter and / or time domain window module 310 , and
`Sub - carrier
`analog to digital converters ( A / D ) 312. A / D converters 312
`Encoding
`convert the sequence into digital signals that are filtered via 20 Sub - carrier
`Encoding
`digital receiver filter 310. Parallel to ] Serial to parallel
`serial module 308 converts the digital time domain signals
`[ 2. The wireless communications device according to
`into a plurality of [ serial ] time domain signals . FFT module
`claim 1 , wherein at least the optimal extended long training
`306 converts the [ serial ] time domain signals into frequency
`domain signals . Frequency domain window 304 applies a 25 sequence is carried by at least 56 active sub - carriers . ]
`weighting factor on each frequency domain signal . Symbol
`[ 3. The wireless communications device according to
`demapper 302 generates the coded bits from each of the 64
`claim 2 , wherein the at least 56 active sub - carriers corre
`subcarriers of an OFDM sequence received from the fre-
`spond to at least indexed sub - carriers –28 to +28 . ]
`4. The wireless communications device according to
`quency domain window .
`FIG . 4 illustrates the long training sequence with a 30 claim [ 2 ] 1 , wherein the optimal extended long training
`minimum peak - to - average power ratio that is used in 56
`sequence has a minimum peak - to - average power ratio of 3.6
`active sub - carriers . Out of the 16 possibilities for the four
`dB .
`new sub - carrier positions , the sequence illustrated in FIG . 4
`[ 5. The wireless communications device according to
`has the minimum peak - to - average power ratio , i.e. , a peak-
`claim 1 , wherein at least the optimal extended long training
`35 sequence is carried by at least 63 active sub - carriers . ]
`to - average power ratio of 3.6 dB .
`FIG . 5 illustrates the long training sequence with a
`[ 6. The wireless communications device according to
`minimum peak - to - average power ratio that is used in 63
`claim 5 , wherein the at least 63 active sub - carriers corre
`active sub - carriers . Out of the 2048 possibilities for the
`spond to at least indexed sub - carriers -32 to +31 . ]
`eleven new sub - carrier positions , the sequence illustrated in
`[ 7. The wireless communications device according to
`FIG . 5 has the minimum peak - to - average power ratio , i.e. , a 40 claim 5 , wherein the optimal extended long training
`sequence has a minimum peak - to - average power ratio of 3.6
`peak - to - average power ratio of 3.6 dB .
`It should be appreciated by one skilled in art , that the
`dB . ]
`present invention may be utilized in any device that imple-
`8. The wireless communications device according to
`ments the OFDM encoding scheme . The foregoing descrip-
`claim 1 , wherein a binary phase shift key encoding is used
`tion has been directed to specific embodiments of this 45 for each sub - carrier above the +26 indexed sub - carrier and
`invention . It will be apparent , however , that other variations
`below the -26 indexed sub - carrier .
`and modifications may be made to the described embodi-
`9. The wireless communications device according to
`ments , with the attainment of some or all of their advantages .
`claim 1 , wherein the Inverse Fourier Transformer comprises
`Therefore , it is the object of the appended claims to cover all
`[ at least one of the following :) an Inverse Fast Fourier
`such variations and modifications as come within the true 50 Transformer [ and ] or an Inverse Discrete Fourier Trans
`spirit and scope of the invention .
`former .
`10. The wireless communications device according to
`claim 1 , wherein the wireless communications device com
`What is claimed :
`prises one or more of the following : a personal digital
`1. A wireless communications device , comprising :
`a signal generator that generates an extended long training 55 assistant , a laptop computer , a personal computer , a proces
`sequence ; and
`sor , and a cellular phone .
`an Inverse Fourier Transformer operatively coupled to the
`11. The wireless communications device according to
`signal generator ,
`claim 1 , wherein the wireless communications device com
`wherein the Inverse Fourier Transformer processes the
`prises a wireless mobile communications device .
`extended long training sequence from the signal gen- 60
`12. The wireless communications device according to
`erator and provides an optimal extended long training
`claim 1 , wherein the wireless communications device com
`sequence with a minimal peak - to - average ratio , and
`prises one or more of the following : an access point and a
`wherein at least the optimal extended long training
`base station .
`sequence is carried by a greater number of subcarriers
`13. The wireless communications device according to
`than a standard wireless networking configuration for 65 claim 1 , wherein the wireless communications device is
`an Orthogonal Frequency Division Multiplexing
`backwards compatible with legacy wireless local area net
`work devices .
`scheme ,
`
`

`

`US RE48,629 E
`
`Sub - carrier
`Encoding
`
`21
`+1
`
`24
`+1
`
`25
`+1
`
`26
`+1 .
`
`5
`
`20
`
`8
`-continued
`22
`23
`-1
`+1
`
`7
`14. The wireless communications device according to
`claim 1 , 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 .
`23. The wireless communications device according to
`15. The wireless communications device according to
`claim 22 , wherein :
`claim 14 , wherein the legacy wireless local area network
`the Inverse Fourier Transformer comprises an Inverse
`device uses the optimal extended long training sequence to
`Fast Fourier Transformer or an Inverse Discrete Fou
`estimate a carrier frequency offset even though the optimal
`rier Transformer ;
`extended long training sequence is longer than the long 10
`the wireless communications device comprises one or
`training sequence that is specified by the legacy wireless
`more of the following : a personal digital assistant , a
`networking protocol standard .
`laptop computer , a personal computer , a cellular
`16. The wireless communications device according to
`phone , an access point , a processor , and a base station ;
`claim 15 , wherein the long training sequence that is specified
`the wireless co