`
`
`
`•••• •••• •••••
`ー-----
`
`l i l -----ー•
`
`掴掴掴掴岨岨ハリ---------nXu ------・戸、 J
`山川田山田川ハリ---------nxu HHHHHウん・・・・・・・司/岨岨岨岨岨岨ハリ|) 咽田山田山田山田 Qば
`l i l ----------l i l ----------l i l -----ー•
`
`
`
`ー----------
`
`I l -----l i l ----------I l -----I l ----------l i l -----I l -----HHHHHHHHHHH4EEA
`
`川川川 B
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 7,280,580 Bl
`Oct. 9,2007
`
`ーー
`
`(12) United States Patent
`Haartsen
`
`5,832,026 A 1111998 Li
`5,848,095 A 12/1998 Deutsch
`5,870,391 A 2/1999 Nago
`5,898,733 A 4/1999 Satyanarayana
`6,480,721 Bl * 11/2002 Sydon et al. ...・ H ・H ・H ・..455/464
`
`FOREIGN PATENT DOCUMENTS
`
`5/1986
`2/1999
`4/1999
`
`0182762 Al
`W099109671
`W099/19993
`* cited by examiner
`
`》 O O
`H W W
`
`Primary Examinerー-CurtisOdom
`(74) Attorneぁ Agent,or Firm-Potomac Patent Group
`PLLC
`
`(57)
`
`ABSTRACT
`
`A hop channel is selected for use in a channel hopping
`communication system that includes a sequence of hop
`channels, wherein the sequence comprises a set offorbidden
`hop channels and a remaining set of allowable hop channels.
`Selection involves selecting a hop channel from the
`sequence as a function of a present phase. If the selected hop
`channel is an allowable hop channel, then the selected hop
`channel is used for communication during the present phase.
`If the selected hop channel is a forbidden hop channel, then
`a time-varying parameter is used to select a substitute hop
`channel from the set of allowable hop channels. The sub-
`stitute hop channel is then used for communication during
`the present phase. The time-varying parameter may, for
`example, be a clock value. With this strategy, the resultant
`hopping sequence is identical to the original hopping
`sequence whenever the original sequence calls for an allow-
`able hop channel. In all other cases, a substitute hop channel
`is dynamically selected from the set of allowable hop
`channels.
`
`42 Claims, 15 Drawing Sheets
`
`(54) HOP SEQUENCE ADAPTATION IN A
`FREQUENCY-HOPPING COMMUNICATIONS
`SYSTEM
`
`(75) Inventor: Jacobus C. Haartsen, Hardenberg (NL)
`
`(73) Assignee: Telefonaktlebolaget L M Ericsson
`(pub1.), Stockholm (SE)
`
`( *) Notice: Subject to any disclaimer, the term ofthis
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 0 days.
`
`(21) Appl. No.: 09/418,562
`
`(22) Filed:
`
`Oct. 15, 1999
`
`(51) Int. C1.
`(2006.01)
`H04B 1/00
`(52) Uふ C1........................................ 375/138; 375/132
`(58) Field of Classification Search ...・ H ・H ・H ・... 375/200,
`375/202,130-153,267; 455/450,464; 370/338,
`370/333, 330
`See application file for complete search history.
`
`(56)
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`4,023,103 A
`5/1977 Malm
`4,476,566 A *
`10/1984 Dent .......................... 375/132
`4,606,040 A
`8/1986 David et al.
`4,716,573 A *
`12/1987 Bergstrom et al. ...・ H ・...375/132
`4,780,885 A *
`1011988 Paul et al. •••••••••••••••••• 375/267
`5,307,348 A
`4/1994 Buchholz et al
`5,323,447 A *
`6/1994 Gillis et al. ...・ H ・.....・ H ・.455/464
`5,408,496 A
`4/1995 Ritz et al
`5,515,369 A
`5/1996 Flanuner, III et al
`5,619,493 A
`4/1997 Ritz et al.
`5,737,358 A
`4/1998 Ritz et al.
`5,809,059 A
`9/1998 Souissi et al
`
`DETERMINE PRESET HOP
`CHANNEL AS FUNCTION OF PHASE
`
`901
`
`903
`
`905
`
`907
`
`909
`
`PRESENT HOP CHANNEL=TABLE(INDEX)
`
`USE PRESENT HOP CHANNEL
`
`0001
`
`Marvell Semiconductor, Inc.
`MediaTek Inc.
`MediaTek USA, Inc.
`Exh. 1006
`IPR of U.S. Pat. No. 7,477,624
`
`
`
`u.s. Patent
`
`Oct. 9,2007
`
`Sheet 1 of 15
`
`US 7,280,580 Bl
`
`一同
`
`MPOE
`
`守主邑守ghでさ
`
`企干l+。切守一円
`
`------E・E・---------------
`
`圃 同
`
`ga守♀N gマN g守N(cid:631)£可
`
`由 ー
`
`、‘‘
`
`廷-
`
`ー手
`
`高是
`
`毛
`
`~ 、、
`
`/ 司、
`
`J 司、
`
`/ 司、、
`
`J ' 司、
`
`/ 司、
`
`~・、
`
`... 司、
`
`0002
`
`
`
`u.s. Patent
`
`Oct. 9,2007
`
`Sheet 2 of 15
`
`US 7,280,580 Bl
`
`hS4ミ守aEhh
`
`(』)吋
`
`‘Jut
`
`∞』「守刊
`
`画-----a------------
`
`4・
`
`宮 守 刊 問 。 守 N
`
`守O守一円
`
`41ー
`
`開。守門
`
`+ 一時
`
`志子可
`
`+・ ... ‘'
`
`RNEミhvghh ‘h
`
` ~ 、
`
`'1!
`
`。国守刺
`
`∞円守利
`
`------z・・・・・・・・・・・・・
`
`sdl ‘を
`
`‘U
`
`U\札
`
`‘ー
`‘を
`
`曜を
`
`‘を
`
`4を
`
`事判明。罰
`
`守 寺 門
`
`包守
`JN
`
`ロ出可刊
`
`-huV向
`
`。
`
`0003
`
`
`
`u.s. Patent
`
`Oct. 9,2007
`
`Sheet 3 of 15
`
`US 7,280,580 Bl
`
`「N
`
`EESK状。言
`
`••••••••••.••••.•••••••••
`
`(γご mu
`
`~
`
`ーを
`
`‘手
`
`モ
`
`,U\は
`
`(cid:631) ‘c、、、
`
`"(
`
`ち高温高岡写制 守寺刊
`
`包サ制
`
`g誌
`
`、宏司
`
`、‘、
`
`RNEミhwむな(cid:631)述内 O等刊
`
`a干
`ト
`
`-EE-----EE---------
`
`i、。市内
`-KAh吋
`
`3haSN 守O司N m O守N SN吾、
`
`.、、
`
`〈と
`
`m,‘望日比
`
`曜を
`
`唱を
`
`モ
`
`‘ー
`
`0004
`
`
`
`u.s. Patent
`
`Oct. 9,2007
`
`Sheet 4 of 15
`
`US 7,280,580 Bl
`
`ハート
`NG\
`・・対勺
`
`\N也、
`
`(守、法
`
`国国国困仁1国
`
`LF88昌吉m
`
`自主同
`
`ハf
`
`ト対寸 U\ミル\に)
`
`(\占、・
`hw\江
`
`祖国国国国[:::;回国
`
`amt
`
`問。\守
`
`品 川 白 γ
`
`0005
`
`
`
`u.s. Patent
`
`U.S. Patent
`
`Oct. 9,2007
`Oct. 9, 2007
`
`Sheet 5 of 15
`Sheet 5 0f 15
`
`US 7,280,580 Bl
`US 7,280,580 B1
`
`向田O同【
`
`8‘
`.s:
`
`m凶MDO凶作阿
`
`E
`D
`O
`H
`LL
`
`In
`
`百四官官。凶百円四国一宮
`
`\
`
`\ G h
`
`C)“-50%
`回目白老若
`an
`3
`'E
`c
`{3*
`“5
`5
`
`h
`«L\
`~
`W
`
`。盟諸向島
`
`phase
`
`fキ
`in
`
`0006
`
`
`
`u.s. Patent
`
`U.S. Patent
`
`Oct. 9,2007
`Oct. 9, 2007
`
`Sheet 6 of 15
`Sheet 6 of 15
`
`US 7,280,580 Bl
`US 7,280,580 B1
`
`4。a2 ‘
`a 。
`N)
`、右 喝、
`、3 •
`
`mwGQXS«5:
`
`9553.,quanRV
`
`、リ-也
`ミqヒ;:,ドh
`
`@8693 \éFumflmwqot
`
`~
`
`をい
`
`三lf
`
`Q 句
`C \\~
`:ttn
`
`u-00向。
`
`Moo—o
`
`0007
`
`
`
`
`u.s. Patent
`
`Oct. 9,2007
`
`Sheet 7 of 15
`
`US 7,280,580 Bl
`
`じ \
`
`.えい
`
`|起¥|芸
`• 、
`‘ 、二
`さtミキ
`一巡叫
`ミミミ
`~~
`
`市W【
`
`m-
`
`寸 同 何 回 N H H a【
`
`で\た』 吋吋
`
`ゴ
`さ4ミ
`さい
`~Öo
`
`ミ主=
`
`o
`~
`。、
`。。
`
`|退治 1\0
`|述、 I~
`
`守
`
`|当吋 1C'l
`|ト|同
`
`一ーもぜまト
`
`hFIll-,
`‘f \もhu
`
`0008
`
`
`
`U .S. Patent
`U.S. Patent
`
`Oct. 9,2007
`Oct. 9, 2007
`
`Sheet 8 of 15
`Sheet 8 of 15
`
`US 7,280,580 Bl
`US 7,280,580 B1
`
`ら。
`
`、
`~ 、.....
`'rl
`
`m Et
`
`Aw
`
`戸、\剖
`
`|記ミ|ぎ
`‘ 、、
`‘且司
`a-
`rt 、』
`さ4と述、
`Xg,
`、、、』
`~~
`wk
`3.
`~~
`3.:3mw:0x3“
`述式
`Jヰミ
`道小
`巡らe
`05‘
`述。
`$3},
`Qv
`~\η
`逗ぺ
`In.Aon0%
`夫U、4
`
`~
`町、
`
`込哩
`
`れ
`
`
`
`d23~<§$m¢vAqumwflugufi
`
`(v)
`
`f'(
`
`~
`、.
`
`.IIIIII
`
`、3
`M
`コ、
`
`0009
`
`
`
`
`
`
`
`u.s. Patent
`
`Oct. 9,2007
`
`Sheet 9 of 15
`
`US 7,280,580 Bl
`
`DETERMINE PRESET HOP
`CHANNEL AS FUNCTION OF PHASE
`
`901
`
`903
`
`INDEX=MOD(CLOCK,N2)+BASE VALUE
`
`PRESENT HOP CHANNEL=TABLE(INDEX)
`
`USE PRESENT HOP CHANNEL
`
`905
`
`907
`
`909
`
`FIG.9
`
`0010
`
`
`
`u.s. Patent
`
`Oct. 9,2007
`
`Sheet 10 of 15
`
`US 7,280,580 Bl
`
`1001 __ 、
`
`IND
`
`(1
`
`(1005
`
`HC 1
`
`HC2
`
`HC 3
`
`HC4
`
`HC5
`
`HC6
`
`HC7
`
`HC8
`
`HC9
`
`.
`.
`.
`
`HC N1
`
`。
`。
`
`。
`。
`。
`。
`
`。
`
`FIG. 10
`
`0011
`
`
`
`u.s. Patent
`
`Oct. 9,2007
`
`Sheet 11 of 15
`
`US 7,280,580 Bl
`
`1107
`
`N2 = NUMBER OF ALLOWABLE
`HOPS
`
`1101
`
`PRESENT HOP CHANNEL =
`HOP CHANNEL (PHASE)
`
`OFFSET = MOD (CLOCK,N2)
`
`INDEX = 1
`
`1109
`
`1111
`
`PRESENT HOP CHANNEL = HOP CHANNEL(INDEX)
`
`1121
`
`FIG. 11
`
`0012
`
`
`
`u.s. Patent
`
`Oct. 9, 2007
`
`Sheet 12 of 15
`
`US 7,280,580 Bl
`
`1201 _、
`
`IND
`
`f 1 0 0 3 f f
`。 。
`。 。
`
`HC 1
`HC2
`HC3
`HC4
`HC5
`HC6
`HC7
`HC8
`HC9
`
`2
`
`。 2
`。 2
`。 3
`。 3
`
`3
`
`.
`
`。 3
`
`.
`
`HC N1
`
`FIG. 12
`
`0013
`
`
`
`u.s. Patent
`
`Oct. 9,2007
`
`Sheet 13 of 15
`
`US 7,280,580 Bl
`
`1307
`
`N2 = NUMBER OF ALLOWABLE
`HOPS
`
`1301
`
`PRESENT HOP CHANNEL =
`HOP CHANNEL (PHASE)
`
`OFFSET = MOD (CLOCK,N2) + 1
`
`LAST GAP COUNT = 0
`
`.1309
`
`1311
`
`PRESENT HOP CHANNEL=
`HOP CHANNEL(OFFSET +LAST GAP COUNT)
`
`1315
`
`1317
`
`LAST GAP COUNT =
`GAP COUNT(OFFSET + LAST GAP COUNT)
`
`FIG. 13
`
`0014
`
`
`
`u.s. Patent
`
`Oct. 9,2007
`
`Sheet 14 of 15
`
`US 7,280,580 Bl
`
`2さ
`
`匂明。k戸時
`
`内同O同 {
`
`~ でト
`旬。 ~ ミ
`..........
`、
`\:h
`|よ
`
`~
`-::r-‘、、
`
`。IIMII守 l四....1~II 四 11 門
`
`円、治、ρミ日円
`
`nkQ士()
`
`ミー
`、、ー
`
`N'\
`l~ 三
`〕ミ
`b
`そZ
`
`。Eoao凶
`
`問。司一
`uo向
`
`。凶同国59HO
`
`‘ • ・・・・・・・・ーーーーー・圃ーーーー・・・・・・・・-----------------・
`
`的司冨
`
`回a
`
`J
`
`沼 恒お凶個目
`
`0015
`
`
`
`u.s. Patent
`
`Oct. 9,2007
`
`Sheet 15 of 15
`
`US 7,280,580 Bl
`
`mv甲
`
`山UN.守Hmmo同
`
`門 戸 。 mu
`
`。∞
`
`N
`,......
`守、
`
`\0
`
`喝品川寸品川ト N
`
`
`
`F、
`
`ぞ~
`
`、リミ均三局、ω
`
`ミ弘
`
`治MV231WY
`
`(也、 \FW江
`
`••••
`。、
`
`\0
`
`町 寸 同 mmoH 。~
`
`F叫
`~
`
`
`
`A山∞
`
`N -一ト
`
`\0
`
`m品川守 N沼 N
`
`
`
`N
`('t')
`
`定 Y
`Eは さ-E1よ尽
`
`ロ~
`
`I."J ul
`
`(du(cid:631)‘主
`
`0016
`
`
`
`US 7,280,580 B1
`
`1
`HOP SEQUENCE ADAPTATION IN A
`FREQUENCY-HOPPING COMMUNICATIONS
`SYSTEM
`
`2
`signature sequence. At the receiver, the same unique signa-
`印 resequence is used to recover the underlying informa-
`tional data stream signal.
`In frequency hopping systems, the spreading is achieved
`5 by transmitting the informational data stream over ever-
`changing radio frequencies. For each communication, the
`Ihe invention relates tO COHmlullcat1011systems where particular frequenciesused by both the transmitter and
`receiver are determined by a predefined frequency hop
`trans111ltter a11d recelver make 118e of a hop sequence to sequalce.The use oftkeq11encyhoPPIng is attract1ve for the
`remain in contact. More particularlぁthei~v:ntion r
`to 10 radio ~pplications ~e~ti~~ed ;b~~~ rb~;ause it more readily
`techniques for dynamically skipping certain hops ofthe hop allows ~the use of cost effective radios.
`A system called Bluetooth was recently introduced to
`sequence.
`In the last several decades, progress in radio and Very provide pervasive connectivity especially between portable
`Large Scale Integrated circuit (VLSI) technology has fos- devices like mobile phones, laptops, personal digital assis-
`tered widespread use of radio communications in consumer 15 tants (PDAs), and other nomadic devices. This system
`applications. Portable devices, such as mobile radios, can applies frequency hopping to enable the construction of
`now be produced having acceptable cost, size and power low-power, low-cost radios with a small footprint. The
`consumption.
`system supports both data and voice. The latter is optimized
`b~ ap?lyi~g fast !requ~cy ~o~p~ng in combination with a
`Although wireless technology is today focused mainly on
`voice communications(e.g.,with respect to handheldmrobust voice coding-The fast frequency hopping has a
`radios), this field will likely expand in the near 印 刷reto nominal rate of 800 hops per second (hops/s) through the
`entire 2.4 GHz ISM band. Devices based on the Bluetooth
`provide greater information flow to and from other types of
`nomadIC deVIceS EU1daxed devicesMore speclacany,1t is system concept cmcreate SO called piconets,which com-
`orise a master device and one or more slave devices con-
`likely that further advances in technology will provide very _ _ l'
`inexpensive radio equipment that can easily be integrated 25nected via the FH piconet channel-The FH sequence used
`into many devices. 百;is--~iil r~duce the ~;mber of ~~bles for the piconet channel is completely determined by the
`C11rrently used-For instance rad10 communication Can address or identity of the device actmg as the master TIle
`th~~~~~~b~r~~f~~abk;:~~~U;;~~;:t system clock of the master d白ev吋lC印ed必耐eteぽrmm
`eliminate or redl悶
`maωst匂erde,町Vl叩ce凶s(伊e.g.,peぽTSωona札1c∞om甲pu凶lteぽrs吋)with their r閃es叩pe氏c- the hopping sequence (i.e., the designation ofwhich one of
`tive peripherals (e.g., printers)・
`30 the possible hops in the sequence is the“cu汀 ent"hop). In the
`Bluetooth system, each device has a free-running system
`~l~~k~ E~~hJ ;ith~ s-l~~~ d~vi~~s -~dd~ a-~~汀esponding time
`百leaforementioned radio communications will require
`an unlicensed band with suflicient capacity to allow for high of志向tto its clock that enables it to become aligned with the
`data rate transmissions. A suitable band is the Industrial clock of the master device. By using the master address to
`Sc制cα1陀悶len臼n凶1
`globa札llyavailable. The band provides 83.5 MHz of radio -- of志向tto align to the master clock, each slave device keeps
`in hop synchrony to the master device; that is, master a~d
`spectrum.
`To allow different radio networks to share the same radio slave -de~ices re~ain in contact by hopping synchronously to
`medium without coordination, 時I叫 spr回 dingis usually the制 nehop企eque即 yor hop carrier. For more details,
`applied. In fact, the Federal Communications Commission 40 reference is made to U.S. patent -application Ser. No. 08/932,
`(FCC) in the United States cu汀 entlyrequires radio equip- 911, filed on Sep. 18, 1997 in the name ofJ. C. Haartsen and
`ment operating in the 2.4 GHz band to apply some form of entitled“Frequency Hopping Piconets in an Uncoordinated
`spectrum spreading technique when the transmit power Wireless MuI1:i-user System," which is hereby incorporated
`exceeds about 0 dBm. Spread spectrum communication herein by reference in its entirety.
`techniques, which have been around since the days of World 45 The hop sequences used in the Bluetooth system are
`War II, are of interest in today's commercial applications generated -thro~gh a hop selection mechanism as described
`because they provide robustness against interference, and in U.S. patent applicati~n Ser. No. 08/950,068, filed on Oct.
`allow for multiple signals to occupy the same radio band at 24, 1997 in the name of J. C. Haartsen and entitled“Method
`the same time.
`and Apparatus for the Generation of Frequency Hopping
`Spreading can either be at the symbol level by applying 50 Sequences," which is hereby incorporated herein by refer-
`direct-sequence (DS) spread spectrum techniques or at the ence in its entirety. With this method, hop carriers are
`channel level by applying frequency hopping (FH) spread generated“on the fly". The mechanism has no inherent
`spectrum techniques. In DS spread spectrum, the informa- memory: address and clock information instantaneously
`tional data stream to be transmitted is impressed upon a determine the sequence and phase and therefore directly
`much higher rate data stream known as a signature sequence. 55 determine the desired hop carrier. The advantages of such a
`Typically, the signature sequence data are binary, thereby selection scheme are numerous. By changing address and
`providing a bit stream. One way to generate this signature clock, a device can jump from one FH piconet channel
`sequence is with a pseudo-noise (PN) process that appears controlled by one address/clock combination to another
`random, but can be replicated by an authorized receiver. The piconet controlled by another address/clock combination. In
`informational data stream and the high bit rate signature 60 this regard, reference is also made to the aforementioned
`sequence stream are combined to generate a stream of application U.S. Ser. No. 08/932,911 describing FH piconets
`so-called “chips" by multiplying the two bit streams in an uncoordinated wireless multi-user system.
`together, assuming the binary values of the two bit streams
`Radio communications intended for local connectivity
`are represe凶 edby +1 or -1. This combination ofthe 1首位er between consumer applications require the use of a free and
`bit rate signal with the lower bit rate data stream is called 65 unlicensed band. As mentioned before, the ISM band at 2.45
`spreading the informational data stream signal. Each infor- GHz is a suitable band because it is available globally
`mational data stream or channel is allocated a unique (although the specific part ofthe ISM band that may be used
`
`pel,ates
`
`BACKGROUND
`
`0017
`
`
`
`US 7,280,580 B1
`
`…r
`一u
`
`u日…一…一一一一………………一一………………一……日………一……一一………一一一口一h…一一………一一
`rr品川一山刊誌記山副知山叩山町出 J M叩日出向山札市町山口吋川町仰向日開古川
`抑 制 m m m叫 的 山 山 h M k m山出立川仙川町加山町仙忠一川町品計抑制出羽山町
`訂叫山氏自 J叫即日…に k m Z Z
`L出 町 pmnT山風 m M O K 即 MV岨 mWPEMMM 枕 札 山 肌 p m叫 削 畑 一 日 出 1 1的 問 削 除 aω 剛山 d 帥 回 一 川 加 戸 加 問 ,d 岡 山 一 山 叩 AmE4mcmtum
`
`4
`
`…一………一一一…………日………………………一一…………日………出…(cid:631)……一一一一………………一……一………………
`…官臨時………日山口一一…日一一一………………略拠出…一一一口…山一昨……叩…山山
`
`h……………………………………………………………………………………………………………
`
`ξJ
`
`ハリ
`
`J
`
`ξJ
`
`ハリ
`
`ξJ
`
`《Jforb
`
`ー《
`
`…………………………日一一一…………
`
`《J1i1iウんウノ
`
`ハリ
`
`ξJ
`
`- 1 d
`
`ハリ
`
`ξJ
`
`吋JA--A-
`
`ハリ
`
`附 巾 m M凶 hmvdm 戸 社 主 吋 川 叩 い い 加 問 削 凶 陥 日
`
`,M
`
`ド バ 心 一 位 九 mmk剛 山 ' 剛 一 山 叫 仙 一 日 間 向 江 川 町 向 山 中 旬 同 士 山 剛 山 間 一 … 州 制 ' 即 日 制 Md 附 加 ahdd帥 よ
`U M M h wぺ C m m 比一川町h 一 叫 刷 出 れ 凶 山 町 白 山 町 山
`
`2 M m w 細 川 刷 畑 一 民 的 時 間 町 山
`
`3
`
`川口
`
`t M d筋立 urじr J Z M m
`
`……一抽出……一………日…品川端…叫……冊一一………田…………一………一昨日…部一回出町叫
`
`………一………即日目………………
`
`判官出む九出品川町山口口zur…立山口砂川11MMTU出口町一副ホUmu--山
`ut…一……………………一一……………一………一品川一一…………一………………………
`
`n・日・uぽ 10raa 閃 c t e c t o o r e l E C d e h r S M v e c h e m o H m則叩・日m d h e h o l o t n n s o 陀 segppsHdw凶 吋
`
`日間叶 md叫ぶ同町叫凶山間血ノ伽制御吋吋山 m w k k m u z z 立 制 凶 月 中 幽 守 山 仙 沼 町 叫 同 吋 出 江 口 白 州 吋 主 叫 吋 ゆ 山 川 山
`器内明MMTujwmm山 町 一 副 附 側 出 品 川 川 均 一 切MTZZMW問 蜘 " ぷ 叩 山 問 問 問 則 氏 k m 目 白 川krU1出む抽出 U
`U ,mMprdd 引 い 阻 ,UJ山 町 M d
`口出…出叫ん山川町一抗出川町山山知山立山川一山Mm品目 h M M W町一品目山口弘一山品計品
`∞ 肝 凹 制 m J 立九州町立凶世話引いぽ Jrpド ド 剛 山 ω国 側A 古 川 町 世 間 印 刷 r d h
`日 m b炉問山,Anu吋 ωm同 一 江 戸3H同州ドヰ一いよ同位 yJU-M 日 即 日 刊 内 山 郎 防 an阿 川 引 明 d m山 川 立 川 百 U L M 机 山 MM目立町均一刷
`
`0018
`
`
`
`US 7,280,580 B1
`
`5
`6
`frequencies in the first sequence in their remaining order. calls for an allowable hop channel. In all other cases, a
`Other hop sequences are similarly derived by using different substitute hop channel is dynamically selected from the set
`decimation numbers.
`of allowable hop channels.
`U.S. Pat. No. 5,809,059, which issued to Souissi et al. on
`In another aspect of the invention, the time-varying
`Sep. 15, 1998, discloses a method and apparatus for spread 5 parameter may be a clock value. In some embodiments, the
`spectrum channel assignment. The technique includes com- time-varying parameter and the present phase may be
`puting average noise and interference levels for different derived from a same clock value. In altemative embodi-
`sequences of channels, and then selecting that one of the ments, the time-varying parameter may be a random value
`sequences of channels having the lowest average noise and or a pseudo-random value.
`interference level for a next transmission of information. 10 In yet another aspect of the invention, hop selection
`U.S. Pat. No. 4,606,040, which issued to David et al. on further comprises forming a sequence of allowable hop
`Aug. 12, 1986, discloses a transmitting-receiving station for channels from the set of allowable hop channels. In this case,
`a system for transmitting data by frequency hopping. In the operation of using a time-varying parameter to select a
`order to facilitate synchronization between two units when substitute hop channel from the set of allowable hop chan-
`one is in a standby mode, a code gene凶 ordefines the use 15 nels comprises forming an index value from the time-
`of a plurality of channels in accordance with a so-called varying parameter; using the index value to select one ofthe
`high-speed skip law for a transmitting-receiving station in allowable hop channels from the sequence of allowable hop
`
`either of the transmitting or recei、ringmodes, and in accor- channels; and using the selected allowable hop channel as
`
`index value=mo的 ime-varyingpararneter, N2)+
`BASE VALUE,
`
`dance with a so-called low-speed skip law for a transmitting- the substitute hop channel.
`receiving station in the stand-by mode. The high叩 eedskip 20 In still another aspect of the invention, the operation of
`law consists ofthe use of each ofthe channels during a time forming the index value from the time-varying parameter
`' while the low-speed 汰 iplaw governs the char創n昭1ge凶soぱft白he c∞omp戸戸n附 deteぽTmm凶nm廿山m昭19the expre 凶 m ・
`Tp
`listening channels employed during NxTp, each correspond-
`ing to a center channel of a sequence of N channels of the
`25
`high-speed skip law.
`U.S. Pat. No. 4,023,103, which issued to Malm on May where mod G,k) denotes j modulo k, N2 is the number of
`10, 1977, discloses a synchronizer for synchronizing a allowable hop channels in the sequence of allowable chop
`frequency hopping receiver with a companion frequency channels and BASE VALUE represents an index value ofthe
`hopping transmitter. The synchronizer includes an electronic O A first allowable hop channel in the sequence of allowable hop
`30
`clock that provides timing pulses for activating a pseudo- J V channels.
`random sequence generator at the frequency hopping rate, In yet another aspect of the invention, the operation of
`and means that cause the clock to skip one activating pulse using a time-varying parameter to select a substitute hop
`every N successive frequency hopping periods, until a channel from the set of allowable hop channels comprises
`frequency hopping local signal and a frequency hopping35determill1ng alIndex value,I,as a fullct1011of the t1mb
`signal from the companion receiver are out of sync by less J J varying parameter; designating one of the allowable hop
`than one frequency hopping period.
`channels in the sequence of hop channels as a first hop
`Each of the above-cited documents discloses a technique channel; starting at the first hop channel, processing the
`for skipping certain hops that has drawbacks, including the sequence ofhop channels to determine an ith allowable hop
`fact that each requires changes to the hop sequence genera- 40 channel in the sequence of hop channels; and selecting the
`tor.
`ith allowable hop channel for use as the substitute hop
`百lereis therefore a need for methods and appara印 sesfor channel.
`In some embodiments, the first hop channel may be the
`removing specific hop frequencies from an arbitrary hopping
`sequence. There is also a need for accomplishing this first hop channel in the sequence of hop channels. In
`without requiring off-line processing. It is also desirable to 45 altemative embodiments, the first hop channel may be a first
`be able to adapt hop sequences dynamically, and to apply hop channel after a last forbidden hop ch制 限1in the
`this adaptation to any existing hop selection scheme or sequence of hop channels. In this case, the operation of
`existing hop sequence.
`processing the sequence ofhop channels to determine an ith
`allowable hop channel in the sequence of hop channels
`50 wraps around to the start of the sequence of hop channels
`when i is greater than the number of hop channels following
`the last forbidden hop channel in the sequence of hop
`In accordance with the present invention, a hop channel is
`channels
`selected for use in a channel hopping communication system
`In still another aspect of the invention, the operation of
`that includes a sequence of hop channels, wherein the
`sequence comprises a set of forbidden hop channels and a 55 processing the sequence ofhop channels to determine an ith
`remaining set of allowable hop channels. In accordance with allowable hop channel in the sequence of hop channels may
`one aspect of the invention, selection involves selecting a altematively comprise, starting at the first hop channel and
`hop channel from the sequence as a function of a present continuing with each successive hop channel in the sequence
`phase. If the selected hop channel is an allowable hop ofhop channels, determining whether the hop channel is an
`channel, then the selected hop channel is used for commu- 60 allowable hop channel; and stopping when an ith allowable
`nication during the present phase. If the selected hop channel hop channel has been identified in the sequence of hop
`is a forbidden hop channel, then a time-varying parameter is channels
`In yet another aspect of the invention, the technique
`used to select a substitute hop channel from the set of
`allowable hop channels. The substitute hop channel is then further comprises determining a gap count for each of the
`used for communication during the present phase. With this 65 hop channels in the sequence of hop channels, wherein the
`strategy, the resultant hopping sequence is identical to the gap count represents how many forbidden hop channels are
`original hopping sequence whenever the original sequence in the sequence of hop channels from the first hop channel
`
`SUMMARY
`
`0019
`
`
`
`US 7,280,580 B1
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`8
`7
`up to and including said each of the hop channels. In these selection mechanism visits a “forbidden" hop, an offset may
`embodiments, the operation of processing the sequence of be temporarily added to the phase such that an allowed hop
`hop channels to determine an ith allowable hop channel in is instead selected. The offset is only applied when a
`the sequence ofhop channels comprises (a) using the index forbidden hop is selected. When an allowed hop is selected,
`value plus a previous gap count to select one of the hop 5 no adjustment is made. As used throughout this disclosure,
`channels from the sequence of hop channels; and (b) using the term “forbidden" refers to a hop channel that should be
`the selected hop channel as the substitute hop channel if the avoided during communication for any of a number of
`selected hop channel is associated with a present gap count reasons. For example, the detection of a substantial amount
`that is equal to the previous gap count, otherwise setting the of interference on a hop channel may make it desirable to
`previous gap count equal to the present gap count and 10 avoid use of that hop channel, at least until the interference
`subsides. It may also be the case that one or more hop
`rep回 tingoperations (a) and (b).
`channels are known to be “reserved" for use by another
`system, so that a present system can avoid experiencing
`interference by avoiding these channels. Similarly, a nearby
`The 0句ectsand advantages of the invention will be 15 system may be 印 刷redto provide a high priority/high
`understood by reading the following detailed description in quality service via one or more hop channels. In this case, a
`conjunction with the drawings in which:
`present system can avoid causing interference on these
`FIG. 1 is a graph depicting an exemplary hop carrier channels (and thereby avoid disturbing the nearby system)
`definition in the ISM band;
`by avoiding the use of these hop channels. These are but
`FIGS.2(α) and 2(b) are graphs depicting examples ofhop 20 mere examples of reasons why one or more hop channels
`carrier definitions in the ISM band in case of thr民 individual may be denoted as “forbidden" hop channels. Those having
`narrowband interferers;
`ordinary skill in the art will recognize that other reasons
`FIGS.3(α) and 3(b) are graphs depicting examples ofhop exist as well, and all such reasons are considered within the
`carrier definitions in the ISM band in case of a single scope of the invention. It will also be recogniz疋dthat the
`wideband interferer;
`25 designation of a hop channel as altematively“forbidden" or
`FIGS. 4(α) and 4(b) illustrate a hop carrier selection “allowed" need not be static, but can instead be determined
`and changed dynamically. For example, an allowed hop
`technique that utilizes a pre-stored sequence;
`FIG. 5 is a block diagram of an exemplary hop carrier channel may become“forbidden" in response to the detec-
`tion of interference on that hop channel, and may later be
`selector for the case of on-the-fly sequence generation;
`FIG. 6 is a block diagram illustrating the general concept 30 again designated as “allowed" when it is detected that the
`of a hop avoidance scheme in accordance with the invention; interference has sufliciently abated.
`In another aspect of the invention, for each phase value
`FIG. 7 is a diagram of a hop sequence having a total ofNl
`associated with a forbidden hop, the transformation of the
`hop channels;
`FIG. 8 is a block diagram illustrating a set of N2 remain- forbidden hop into an allowed hop may be evenly distributed
`ing allowable hop channels in accordance with one aspect of 35 over the allowed hops by using a time-varying parameter as
`the basis for making a selection, such as using a time-
`the invention;
`FIG. 9 is a flow chart of operations in accordance with one varying parameter to form the offset amount described
`above. For example, selection (eιvia the offset amount)
`embodiment of the invention;
`FIG. 10 is a diagram of a table that may be stored in a may be varied as a function of the system clock. Altema-
`memory for use in determining a substitute hop channel in 40 tively, selection may be made on the basis of a random or
`pseudo-random parameter. As a result, the randonmess that
`accordance with an embodiment of the invention;
`FIG. 11 is a flow chart of operations for determining a characterizes the initial FH sequence (which uses all hop
`suitable hop channel in accordance with one embodiment of frequencies) is preserved in the final, revised FH sequence
`the invention;
`(which has the same sequence length as the initial FH
`FIG. 12 is a diagram of a table that may be stored in a 45 sequence, but which uses only the allowed hop frequencies).
`memory for use in determining a substitute hop channel in In addition, each hop carrier in the revised FH sequence may
`accordance with an altemative embodiment ofthe invention; be visited with equal probability. Because of the feature
`FIG. 13 is a flow chart of operations for determining a whereby allowed hops continue to be used during their
`suitable hop channel in accordance with an alternative originally-scheduled phase values, the original FH sequence
`50 is reflected in the revised FH sequence: Only during phase
`embodiment of the invention;
`FIG. 14 is a block diagram of a frequency hop generator values associated with forbidden hops are substitute (al-
`for use in a Bluetooth system, in accordance with an lowed) hops utilized. This allows slave units participating on
`embodiment of invention; and
`the hopping channel to remain synchronized even if once in
`FIGS. 15(α) and 15(b) depict a comparison between an a while, they miss a hop (i.e., when the forbidden hop is
`original and a corresponding revised hopping scheme, in 55 replaced by an allowed hop).
`accordance with the invention.
`These and other aspects of the invention will now be
`further described in greater detail.
`In general a hop selection scheme includes thr民 compo-
`nents: a白xedset of carriers to hop over (0武enrefer汀Tedto
`I百1t記e various features of the invention will now be 60 heぽ:relnas “hop chann記lels"
`described wi抗thr閃es叩pe氏cttωo the白gur閃es臥, inwhiにichlike parts are carriers that is followed as hopping progresses, and a phase
`identified with the same reference characters.
`that points to a particular place in the hop sequence. As the
`百letechniques described herein achieve the skipping of phase progresses, the system hops from one hop channel in
`certain hops in a hop sequence without having to change the the FH sequence to the next according to the defined
`hop sequence generator. Instead, a transformation operation 65 sequence, thereby operating at each of the carriers at one
`is performed in which a “forbidden" hop serves as the basis time or another. Most FH systems that use the ISM band at
`for determining an“allowed" hop. For example, if the hop 2.45 GHz have a carrier definition as shown in FIG. 1. The
`
`DETAILED DESCRIPTION
`
`0020
`
`
`
`US 7,280,580 B1
`
`10
`9
`83.5 MHz available radio spectrum at this ISM band is random properties of the FH sequence. If one were to use a
`divided into 79 carriers equally spaced by 1 MHz. The first fixed replacement of occupied carrier A by a clean carrier K,
`carrier is at 2402 MHz and the last carrier is at 2480 MHz. then K would be visited twice as often as the carriers not
`No hops are defined at the edges of the ISM band in order used for replacement, and this would violate the uniform
`to satisfシtherequirements on out-of-band spurious signals 5 probability requirement.
`In conventional FH systems, the sequences are pre-stored.
`using relaxed radio transmitter design.
`百lese79 carriers form the set of carriers that FH systems At the time of counection 印 刷p,one of the sequences, X, is
`such as IEEE 802.11 and Bluetooth hop over. The sequence selected which designates both the particular set offrequen-
`determines the order in which the hops are utilized (0自己n cies to be used and the ordering of those frequencies. During
`referred to herein as“visited"). To allow fair access to this 10 operation, the phase value determines the hop position ofthe
`ISM band, regulatory bodies like the FCC in the U.S. and the connection within the sequence. The rate of change of the
`Conference of European Posts and Telecommunications phase value determines the hop rate. A conventional hop
`(CEPT) in Europe have defined certain rules to which FH selection scheme is shown in FIGS. 4(α) and 4(b). In FIG.
`radios using the ISM band have to conform. For example, 4(α), the original sequence X is stored in an addressable
`the FCC requires that at least 75 hop carriers be used, and 15 memory 403. In operation, an address selector 401 receives
`that, on average, each hop carrier be visited with equal a phase value, and converts this into an address for retrieving
`probability. In addition, in a 30 second period, the accumu- the frequency to be used for a next hop.
`In FIG. 4(b), another sequence, Y, is stored in the memory
`lated dwell time on a single hop should not be gr回 terthan
`400 ms. In the IEEE 802.11 standard, the sequence length is 403. The sequence Y is similar to the original sequence X,
`exactly 79 and each hop carrier is visited only once in the 20 but has one or more carriers removed. (In the example of
`sequence. The sequence has a repetition interval of79 hops. FIG. 4(b), the hops at 2465 MHz and 2478 MHz have been
`The sequence does not have to have a length identical to rem