Pre-inverse ᆺ ᆺ ANC ࢩࢫࢸ࣒ࡢ ᥎ᐃ⢭ᗘᨵၿ㛵ࡍࡿ◊✲
2017 ᖺ 1 ᭶
ᵳᚿ
ෆ
ෆᐜ᱾ᴫ
ᮏㄽᩥࡣ㸪Pre-inverse ᆺࢡࢸࣈࣀࢬࢥࣥࢺ࣮ࣟࣝ㸦ANC: Active Noise
Control㸧ࡢ᥎ᐃ⢭ᗘᨵၿᡭἲࡘ࠸࡚ᥦ㸪᳨ウࡋࡓ◊✲ᡂᯝࢆࡲࡵࡓࡶࡢ࡛
࠶ࡿ㸬ANC ࢩࢫࢸ࣒ࡣ㦁㡢ᑐࡋ㸪ྠᖜ࡛㏫┦ࡢఝ㦁㡢ࢆⓎ⏕ࡉࡏࡿࡇ
ࡼࡾே㛫ࡗ࡚ᛌ࡛࠶ࡿ㦁㡢ࢆᡴࡕᾘࡍᢏ⾡࡛࠶ࡿ㸬ANCࢩࢫࢸ࣒࡛
ࡼࡃ⏝ࡉࢀ࡚࠸ࡿFiltered-xࣝࢦࣜࢬ࣒ࡣ㸰ḟ⤒㊰ࡢኚືᑐࡍࡿ㏣ᚑࡀ㐜
࠸ሙྜࡸኚືࡀࡁ࠸ሙྜࡣࢩࢫࢸ࣒ࡀⓎᩓࡋ࡚ࡋࡲ࠺ၥ㢟ࡀ࠶ࡿ㸬ࡇࡢၥ㢟
ࢆゎỴࡍࡿࡓࡵPre-inverseᆺANCࢩࢫࢸ࣒ࡀᥦࡉࢀ࡚࠸ࡿࡀ㸰ḟ⤒㊰ࢆ᥎ ᐃࡍࡿ㐺ᛂࣇࣝࢱࡢ᭦᪂ࣝࢦࣜࢬ࣒࡛ồࡵࡿホ౯㛵ᩘࡢ໙㓄እᡂศࡀ
ྵࡲࢀࡿࡇࡼࡾࣂࢫࢆᣢࡗࡓㄗᕪ(ࣂࢫㄗᕪ)ࡀⓎ⏕ࡋ㸪᥎ᐃ⢭ᗘࡀ
ຎࡋ࡚ࡋࡲ࠺ၥ㢟ࡀ࠶ࡿ㸬᥎ᐃ⢭ᗘࢆྥୖࡉࡏࡿࡓࡵࡣ⏝࠸ࡿ⿵ຓ㞧㡢ࡢ 㟁ຊࢆࡁࡃࡍࡿᚲせࡀ࠶ࡾ㸪ࡇࡢ⿵ຓ㞧㡢ࡀࢩࢫࢸ࣒యࡢ᥎ᐃ⢭ᗘࡢຎ
ࢆᘬࡁ㉳ࡇࡋ࡚ࡋࡲ࠺㸬
௨ୖࡢࡼ࠺࡞ᢏ⾡ⓗ⫼ᬒࡢࡶ⾜ࡗࡓ◊✲ࢆࡲࡵࡓᮏㄽᩥࡣ㸲❶ࡼࡾ࡞
ࡾ㸪ࡲࡎ㸪➨㸯❶࡛ࡣ㸪ᗎㄽࡋ࡚ᮏ◊✲ࢆ⾜࠺⮳ࡗࡓ⫼ᬒ㸪ᚑ᮶ࡢ◊✲ᴫせ㸪 ᮏ◊✲ࡢ┠ⓗ୪ࡧྛ❶ࡢᴫせࢆ㏙࡚࠸ࡿ㸬
➨㸰❶࡛ࡣ㸪Pre-inverse ᆺANCࢩࢫࢸ࣒ࡢ㦁㡢㝖ཤᛶ⬟ྥୖࢆ┠ⓗࡋ㸪⿵
ຓ㞧㡢ࢆ⏝࠸࡞࠸ Pre-inverse ᆺ ANC ࢩࢫࢸ࣒ࢆᥦࡍࡿ㸬Pre-inverse ᆺ ANC ࢩࢫࢸ࣒ࡣ㸰ḟ⤒㊰ࡢ㏫ఏ㐩㛵ᩘࢆ᥎ᐃࡋ㸪ࡑࡢ᥎ᐃ್ࢆ㸰ḟ⤒㊰ࡢ๓ẁࣇ
ࣝࢱࡋ࡚㓄⨨ࡋ㸪㸰ḟ⤒㊰ࡢไᚚࢆ⾜࠺ࡶࡢ࡛࠶ࡿ㸬㸰ḟ⤒㊰ࡢఏ㐩㛵ᩘࡣ
ࢆ㌿ࡋ࡚ࡋࡲ࠺Ⓨᩓࡋ࡚ࡋࡲ࠺ྍ⬟ᛶࡀ࠶ࡿ㸬ࡑࡇ࡛㸪㐺ᛂᣦᩘࣇࣝࢱࢆ
⏝࠸ࡿࡇ࡛㸪㸰ḟ⤒㊰ఏ㐩㛵ᩘࡢ᭱ᑠ┦㒊᭱┦㒊ࢆศ㞳ࡋ࡚᥎ᐃࢆ
⾜࠸㸪ࡑࢀࡒࢀࡢ㏫ఏ㐩㛵ᩘࢆồࡵࡿࡇ࡛Pre-inverseᆺANCࢩࢫࢸ࣒ࢆᵓᡂ ࡍࡿ㸬ィ⟬ᶵࢩ࣑࣮ࣗࣞࢩࣙࣥࡼࡗ࡚Filtered-xࣝࢦࣜࢬ࣒ẚ㍑ࢆ⾜࠸ᥦ
ᡭἲࡢ᭷⏝ᛶࢆ☜ㄆࡋ࡚࠸ࡿ㸬
➨㸱❶࡛ࡣ㸪⿵ຓࣇࣝࢱࡼࡿ㸰ḟ⤒㊰㏫ఏ㐩㛵ᩘ᥎ᐃࢆ⏝࠸ࡿPre-inverse ᆺ ANCࢩࢫࢸ࣒ࢆᥦࡍࡿ㸬ᚑ᮶◊✲ࡉࢀ࡚ࡁࡓPre-inverse ᆺANCࡣ㸪㸰ḟ
⤒㊰ࡢఏ㐩㛵ᩘࢆ᥎ᐃࡍࡿ㐺ᛂࣇࣝࢱࡢ᭦᪂ࣝࢦࣜࢬ࣒࡛ồࡵࡿホ౯㛵ᩘ
ࡢ໙㓄እᡂศࡀྵࡲࢀࡿࡇࡼࡾࣂࢫࢆᣢࡗࡓㄗᕪࡀⓎ⏕ࡋ㸪᥎ᐃ
⢭ᗘࡀຎࡋ࡚ࡋࡲ࠺ၥ㢟ࡀ࠶ࡿ 㸬እࣟࣂࢫࢺ࡞ࣝࢦࣜࢬ࣒ࡋ࡚
SSCF(Square Sum of Correlation Function)㐺ᛂࣝࢦࣜࢬ࣒ࡀᥦࡉࢀ࡚࠸ࡿ㸬 SSCF 㐺ᛂࣝࢦࣜࢬ࣒ࡣ㦁㡢※㸰ḟ⤒㊰ࢆ᥎ᐃࡍࡿࡓࡵຍࡍࡿ⿵ຓ㞧 㡢ㄗᕪಙྕࡢ┦┦㛵㛵ᩘࢆホ౯㛵ᩘࡍࡿࡇࡼࡾ㸪እࡢᙳ㡪ࢆᢚ࠼
ࡓ㸰ḟ⤒㊰᥎ᐃࢆྍ⬟ࡍࡿ㸬ࡋࡋ㸪┿ࡢ┦┦㛵㛵ᩘࢆィ⟬ࡍࡿࡓࡵࡣ㛗
㛫 ᐃࡀᚲせ࡛࠶ࡾ㸪ᐇ⏝ୖࣂࢫㄗᕪࢆᢚᅽࡍࡿࡇࡀ࡛ࡁࡎእ
ࡢᙳ㡪ࢆཷࡅ࡚ࡋࡲ࠺㸬ࡑࡇ࡛㸪ࡇࡢၥ㢟ࢆゎỴࡍࡿࡓࡵ⿵ຓࣇࣝࢱࡼ
ࡿ㸰ḟ⤒㊰㏫ఏ㐩㛵ᩘ᥎ᐃࢆ⏝࠸ࡿPre-inverseᆺANCࢩࢫࢸ࣒ࢆᥦࡍࡿ㸬ᮏ ᡭἲࡣ㸰ḟ⤒㊰ᑐࡋ࡚⿵ຓࣇࣝࢱࢆ୪ิ㓄⨨ࡋࢩࢫࢸ࣒ྠᐃࢆ⾜࠸㸪⿵
ຓࣇࣝࢱᑐࡋ㸪⦪⥆㸰ḟ⤒㊰ࡢ㏫ఏ㐩㛵ᩘࢆ᥎ᐃࡍࡿࣇࣝࢱࢆ㓄⨨ࡍ
ࡿ㸬ࡇࢀࡼࡾ㸰ḟ⤒㊰ࢆ᥎ᐃࡍࡿ㐺ᛂࣇࣝࢱࡢ᭦᪂ࣝࢦࣜࢬ࣒࡛ồࡵࡿ
ホ౯㛵ᩘࡢ໙㓄እࡼࡿಙྕᡂศࢆྵࡲ࡞࠸ᅇ㊰ᵓᡂ࡞ࡿࡓࡵ㸪ࣂ
ࢫㄗᕪࡀ⌮ㄽୖⓎ⏕ࡋ࡞࠸㸬ࡇࢀࡼࡾ㸰ḟ⤒㊰ࡢ᥎ᐃ⏝ࡍࡿ⿵ຓ㞧㡢ࡢ
ㄽ
ㄽᩥ┠ḟ
➨㸯❶ ᗎㄽ ··· 1
1.1 ᮏ◊✲ࡢ⫼ᬒ··· 1
1.2 ◊✲┠ⓗ◊✲ᴫせ ··· 4
➨㸰❶ ⿵ຓ㞧㡢ࢆ⏝࠸࡞࠸ Pre-inverse ᆺ ANC ࢩࢫࢸ࣒
7
2.1 ㅖゝ ··· 7
2.2 ᇶᮏཎ⌮ ··· 9
2.2.1 㸰ḟ⤒㊰ࡢ᥎ᐃ ··· 11
2.2.2 㸯ḟ⤒㊰ࡢ᥎ᐃ ··· 20
2.2.3 㸯ḟ⤒㊰㸰ḟ⤒㊰ྠ᥎ᐃࡢၥ㢟Ⅼ ··· 22
2.3 ィ⟬ᶵࢩ࣑࣮ࣗࣞࢩࣙࣥ ··· 23
2.4 ⤖ゝ ··· 29
➨㸱❶ ⿵ຓࣇࣝࢱࡼࡿ㸰ḟ⤒㊰㏫ఏ㐩㛵ᩘ᥎ᐃࢆ⏝࠸ࡿ Pre-inverse ᆺ ANC ࢩࢫࢸ࣒ 31
3.1 ㅖゝ ··· 313.2 SSCFࢆ⏝࠸ࡓPre-inverseᆺANCࢩࢫࢸ࣒··· 33
3.3 ⿵ຓࣇࣝࢱࡼࡿ㸰ḟ⤒㊰㏫ఏ㐩㛵ᩘ᥎ᐃࢆ⏝࠸ࡿ Pre-inverseᆺANCࢩࢫࢸ࣒ ··· 39
3.4 ィ⟬ᶵࢩ࣑࣮ࣗࣞࢩࣙࣥ ··· 44
3.4.1 ࢩ࣑࣮ࣗࣞࢩࣙࣥ᮲௳ ··· 44
3.4.2.1 ࢱࢵࣉᩘࡢ᳨ウ ··· 48
3.4.2.2 㐜ᘏᩘzMࡢ᳨ウ ··· 49
3.4.3 㸰ḟ⤒㊰ࡢ᥎ᐃ⢭ᗘࡢẚ㍑ ··· 50
3.4.4 㦁㡢పῶᛶ⬟ ··· 52
3.4.5 ₇⟬㔞ࡢẚ㍑ ··· 54
3.5 ᐇᐇ㦂 ··· 55
3.5.1 ᐇ᮲௳ ··· 55
3.5.2 ᐇ⤖ᯝ ··· 58
3.6 ⤖ゝ ··· 60
➨ ➨㸲❶ ⤖ㄽ 61
ㅰ㎡ 65
ཧ⪃ᩥ⊩ 67
◊✲ᴗ⦼ 71
ᅗ
ᅗ┠ḟ
ᅗ 2. 1 ⿵ຓ㞧㡢ࢆ⏝࠸࡞࠸Pre-inverseᆺANCࢩࢫࢸ࣒ᵓᡂᅗ ··· 10
ᅗ 2. 2 ⿵ຓ㞧㡢ࢆ⏝࠸࡞࠸Pre-inverseᆺANCࢩࢫࢸ࣒ࡢ㸰ḟ⤒㊰ᵓᡂᅗ 11 ᅗ 2. 3 HˆSMc (z)ᵓᡂᅗ ··· 13
ᅗ 2. 4 HˆSAc (z)ᵓᡂᅗ ··· 14
ᅗ 2. 5 HˆSMc (z)HˆSAc (z)ࡢ᥎ᐃࡢಙྕࡢὶࢀ ··· 15
ᅗ 2. 6 s(m)⟬ฟᅇ㊰ ··· 18
ᅗ 2. 7 s(m)㸪v(m)㸪v(mV)ࡢ㛵ಀ ··· 18
ᅗ 2. 8 㸰ḟ⤒㊰᮰ࡢࣈࣟࢵࢡᅗ ··· 21
ᅗ 2. 9 Filtered-xࣝࢦࣜࢬ࣒ ··· 25
ᅗ 2. 10 ࢩ࣑࣮ࣗࣞࢩࣙࣥ⤖ᯝ ··· 28
ᅗ 3. 1 Pre-inverse ᆺANCࡢᵓᡂᅗ ··· 34
ᅗ 3. 2 HˆSc(z)᥎ᐃࡢಙྕࡢὶࢀ ··· 36
ᅗ 3. 3 ⿵ຓࣇࣝࢱࡼࡿ㸰ḟ⤒㊰㏫ఏ㐩㛵ᩘ᥎ᐃࢆ⏝࠸ࡿ Pre-inverseᆺANCࢩࢫࢸ࣒ ··· 39
ᅗ 3. 4 HˆS(z)᥎ᐃࡢಙྕࡢὶࢀ ··· 41
ᅗ 3. 5 HˆSc(z)᥎ᐃࡢಙྕࡢὶࢀ ··· 41
ᅗ 3. 6 ࢲࢡࢺࣔࢹࣝ ··· 44
ᅗ 3. 7 㸯ḟ⤒㊰ࡢࣥࣃࣝࢫᛂ⟅ ··· 45
ᅗ 3. 9 ࢱࢵࣉᩘࡢ᳨ウ ··· 48
ᅗ 3.10 㐜ᘏᩘࡢ᳨ウ ··· 49
ᅗ 3.11 㸰ḟ⤒㊰᥎ᐃ⢭ᗘẚ㍑ᵓᡂᅗ ··· 50
ᅗ 3.12 㸰ḟ⤒㊰᥎ᐃ⢭ᗘẚ㍑(ANR=0dB) ··· 51
ᅗ 3.13 㸰ḟ⤒㊰᥎ᐃ⢭ᗘẚ㍑(ANR=-20dB) ··· 51
ᅗ 3.14 ࢩ࣑࣮ࣗࣞࢩࣙࣥ⤖ᯝ(ANR=0dB) ··· 53
ᅗ 3.15 ࢩ࣑࣮ࣗࣞࢩࣙࣥ⤖ᯝ(ANR=-20dB) ··· 53
ᅗ 3.16 ᐇࢩࢫࢸ࣒ᵓᡂ ··· 55
ᅗ 3.17 ᐇ㦂㢼ᬒ ··· 56
ᅗ 3.18 ᾘ㡢ຠᯝ ··· 59
ᅗ 3.19 ᾘ㡢ຠᯝ㸦ࣃ࣮࣡ࢫ࣌ࢡࢺࣝ㸧 ··· 59
⾲┠ḟ
⾲ 2.1 G*(z)HP(z)ࡢタᐃ್ ··· 24
⾲ 2.2 ࢩ࣑࣮ࣗࣞࢩࣙࣥタᐃ್ ··· 26
⾲ 3.1 ࢩ࣑࣮ࣗࣞࢩࣙࣥᐇ㦂タᐃ್ ··· 46
⾲ 3.2 㸯ࢧࣥࣉࣝ࠶ࡓࡾࡢ₇⟬ᅇᩘ ··· 54
⾲ 3.3 ᐇࢩࢫࢸ࣒࡛⏝ࡋࡓᶵჾ ··· 57
⾲ 3.4 ᐇᐇ㦂タᐃ್ ··· 57
せグྕ
➨㸰❶
グྕ ព࣭ᐃ⩏
) (n g
) (n p
) (n y
) (n f
) (n d
) ec(n
) (n q
) (n gCc
) (z HP
) (z HS
) (z HSM
) (z HSA
) ˆ (z HSMc
㦁㡢
㸯ḟ⤒㊰㏻㐣ᚋࡢ㦁㡢 ほ ಙྕ
ไᚚಙྕ
㸰ḟ⤒㊰㏻㐣ᚋࡢไᚚಙྕ
ㄗᕪಙྕ
᭱┦㒊㏫ࣇࣝࢱ㏻㐣ᚋࡢಙྕ
㸰ḟ⤒㊰ࡢධຊಙྕ
㸯ḟ⤒㊰ఏ㐩㛵ᩘ
㸰ḟ⤒㊰ఏ㐩㛵ᩘ
㸰ḟ⤒㊰ఏ㐩㛵ᩘࡢ᭱ᑠ┦㒊 㸰ḟ⤒㊰ఏ㐩㛵ᩘࡢ᭱┦㒊
㸰ḟ⤒㊰᭱ᑠ┦㒊㏫ఏ㐩㛵ᩘࢆ᥎ᐃࡍࡿᣦᩘᆺ㐺ᛂ
ࣇࣝࢱ
r
> @
E ) ˆ (z HSAc
M ) (n wj
E ) (z Q
V ) (n bq
) ˆ (
, z
HOcSA ) [(m
) (z S
si
) (m s
) (m v
) (z HT
) ˆ (z HCc
F ) (n pi
*
pi
)
*(z G
*
gi
*
ai
L EV(l)
࣐ࢡ࣮ࣟࣜࣥᒎ㛤㏆ఝ㡯ᩘ
㞟ྜᖹᆒ
㸰ḟ⤒㊰᭱┦㒊ఏ㐩㛵ᩘࢆ᥎ᐃࡍࡿ㐺ᛂࣇࣝࢱ )
ˆ (z
HSAc ࡢࢱࢵࣉᩘ
) ˆ (z
HSAc ࡢࢱࢵࣉಀᩘ
) ˆ (z
HSAc ᭦᪂ࣝࢦࣜࢬ࣒ࡢࢫࢸࢵࣉࢧࢬ
᭱┦㒊㏫ࣇࣝࢱ )
(z
Q ࡢࢱࢵࣉᩘ
) (z
Q ࡢࢱࢵࣉಀᩘ
᥎ᐃᚋࡢHˆSAc (z)ఏ㐩㛵ᩘ
HˆOc,SA(z)1ࡢࣥࣃࣝࢫᛂ⟅) (z
Q ⟬ฟࡍࡿࡓࡵࡢኚࣇࣝࢱ )
(z
S ࡢࢱࢵࣉಀᩘ
) (z
S ࡢ㏫zኚ
) (z1
S ࡢ㏫zኚ
㏫ࣇࣝࢱ㸰ḟ⤒㊰ࡢྜᡂఏ㐩㛵ᩘ
㸯ḟ⤒㊰ఏ㐩㛵ᩘࢆ᥎ᐃࡍࡿ㐺ᛂࣇࣝࢱ )
ˆ (z
HCc ࡢࢱࢵࣉᩘ
) ˆ (z
HCc ࡢࢱࢵࣉಀᩘ
) (z
HP ࡢࢱࢵࣉಀᩘ
) (z
HSM ࢆᵓᡂࡍࡿࢺࣛࣥࢫࣂ࣮ࢧࣝᆺࣇࣝࢱ )
*(z
G ࡢࢱࢵࣉಀᩘ
) (z
HSA ࡢࢱࢵࣉಀᩘ
ࣈࣟࢵࢡ㛗 ホ౯㛵ᩘ
➨㸱❶
グྕ ព࣭ᐃ⩏
) (z HP
) (z HS
) ˆ (z HC
) ˆ (z HSc
) (n g
) (n p
) (n y
) (n w
) (n f
) (n d
) (n ec
NC
) ˆ (
, n
hCi PC
PSc )
~(n w
)
~( n f
M x P P
㸯ḟ⤒㊰ఏ㐩㛵ᩘ
㸰ḟ⤒㊰ఏ㐩㛵ᩘ
㸯ḟ⤒㊰ఏ㐩㛵ᩘࢆ᥎ᐃࡍࡿ㐺ᛂࣇࣝࢱ 㸰ḟ⤒㊰㏫ఏ㐩㛵ᩘࢆ᥎ᐃࡍࡿ㐺ᛂࣇࣝࢱ 㦁㡢
㸯ḟ⤒㊰㏻㐣ᚋࡢ㦁㡢 ほ ಙྕ
⿵ຓ㞧㡢 ไᚚಙྕ
㸰ḟ⤒㊰㏻㐣ᚋࡢไᚚಙྕ
ㄗᕪಙྕ
) ˆ (z
HC ࡢࢱࢵࣉᩘ
) ˆ (z
HC ࡢࢱࢵࣉಀᩘ
) ˆ (z
HSc ᭦᪂ࣝࢦࣜࢬ࣒ࡢࢫࢸࢵࣉࢧࢬ )
ˆ (z
HC ᭦᪂ࣝࢦࣜࢬ࣒ࡢࢫࢸࢵࣉࢧࢬ 㸰ḟ⤒㊰㏻㐣ᚋࡢw(n)
㸰ḟ⤒㊰㏻㐣ᚋࡢf(n) 㐜ᘏᩘ
㛫ᖹᆒ
SSCFࣝࢦࣜࢬ࣒ࡢࢫࢸࢵࣉࢧࢬ
┦㛵㛵ᩘィ⟬⠊ᅖ
P
ScANR EV(l) EA(l) )
3(n e
) (l PY
) ˆ (z
HS ᭦᪂ࣝࢦࣜࢬ࣒ࡢࢫࢸࢵࣉࢧࢬ
⿵ຓ㞧㡢ᑐ㦁㡢㟁ຊẚ
⿵ຓ㞧㡢ࡢᙳ㡪ࢆ㝖࠸ࡓ㦁㡢ᡴᾘࡋ⢭ᗘ
⿵ຓ㞧㡢ࡢᙳ㡪ࢆྵࡴ㦁㡢ᡴᾘࡋ⢭ᗘ 㸰ḟ⤒㊰᥎ᐃㄗᕪ
ᖹᆒฟຊ㟁ຊ
➨ 1 ❶
ᗎㄽ
1.1 ᮏ◊✲ࡢ⫼ᬒ
⚾㐩ࡢ᪥ᖖ⏕ά㡢ࡣᐦ᥋࡞⧅ࡀࡾࡀ࠶ࡿ㸬㡢ᴦࡢࡼ࠺࡞ᚰᆅࡼ࠸㡢ࡔࡅ࡛
࡞ࡃ㸪ᛌឤࡌࡿ㦁㡢ࡋ࡚⏕άࡢጉࡆ࡞ࡗ࡚ࡋࡲ࠺ࡶ࠶ࡿ㸬୍⯡⏕
ά࠾࠸࡚㸪㏆㞄ఫẸࡢࢺࣛࣈࣝࡢཎᅉࡢ㸯ࡀ⏕ά㦁㡢࡛࠶ࡿࡢሗ࿌ࡀ
࠶ࡿ[1]㸬ࡲࡓ㸪ᕤሙࡸᴗᡤࡽⓎ⏕ࡍࡿ㦁㡢ࡣ㦁㡢つไἲࡸྛ⮬యࡢ᮲
ࡼࡗ࡚ཝࡋࡃไ㝈ࡉࢀ࡚࠾ࡾ㸪ࡲࡓ⎔ቃᇶ‽ἲ➨᮲࡛ࡣ㦁㡢ࡣබᐖࡋ࡚
ྲྀࡾᢅࢃࢀ࡚࠸ࡿ࡛࠶ࡿ㸬㦁㡢ࡢၥ㢟ࡣே㛫ࡢ⪥࡛⪺ࡇ࠼ࡿྍ⫈ᖏᇦ㡢ࡢ
ࡳࡢၥ㢟࡛ࡣ࡞࠸㸬㏆ᖺ㸪⏕ྍ⬟࢚ࢿࣝࢠ࣮ࡋ࡚ὀ┠ࢆᾎࡧ࡚࠸ࡿ㢼ຊⓎ㟁 ᶵࡽⓎ⏕ࡍࡿ㢼ษࡾ㡢ࡸື➼ࡢప࿘Ἴ㡢ࡼࡗ࡚㸪▱ࡽࡎ▱ࡽࡎࡢ࠺ࡕ
ᗣ⿕ᐖࢆ⿕ࡗ࡚ࡋࡲ࠺ࡀ࠶ࡿ㸬ࡲࡓ㸪㦁㡢ࡀᛌ࡛࠶ࡿࡇࢆ㏫ᡭࡾ㸪
⪥㞀ࡾ࡛࠶ࡿ㧗࿘Ἴ㡢ࢆࢃࡊⓎࡍࡿࡇࡼࡾ㸪῝ኪࡢබᅬタഛࡢ◚ᦆ⾜Ⅽ 㜵Ṇࡢᑐ⟇ࡋ࡚⮬యࡀྲྀࡾ⤌ࢇ࡛࠸ࡿࡶ࠶ࡿ[2]㸬
ே㛫ࡗ࡚ᛌ࡛࠶ࡿ㦁㡢ࢆゎỴࡍࡿࡓࡵ㸪ᚑ᮶ࡽ྾㡢ᮦ࡞ࢆ⏝
ࡋࡓཷື㦁㡢ไᚚ(PNC : Passive Noise Control)ࡢᢏ⾡ࡀࡼࡃ⏝࠸ࡽࢀ࡚ࡁࡓ㸬ࡋ
࡞ࡿࡓࡵࢥࢫࢺࡢၥ㢟ࡸ᪤Ꮡタࡢタ⨨ሙᡤࡢၥ㢟ࡀ࠶ࡿ㸬PNC ᑐࡋ㸪㐺 ᛂࣇࣝࢱ(ADF : Adaptive Digital Filter)[3]ࢆ⏝࠸ࡓᾘ㡢ᢏ⾡ࡋ࡚⬟ື㦁㡢ไ ᚚ(ANC : Active Noise Control)ࡀ࠶ࡿ[4]㸬ࡇࡢᢏ⾡ࡣ㦁㡢ᑐࡋ㸪ྠᖜ࡛㏫
┦ࡢఝ㦁㡢ࢆⓎ⏕ࡉࡏࡿࡇࡼࡾ㦁㡢ࢆᡴࡕᾘࡍᢏ⾡࡛࠶ࡿ㸬ANC ࢩࢫࢸ
࣒ࡣཧ↷࣐ࢡࣟ࣍ࣥࡽྲྀᚓࡋࡓ㦁㡢ಙྕㄗᕪ࣐ࢡࣟ࣍ࣥࡽྲྀᚓࡋ ࡓఝ㦁㡢ࢆࡪࡘࡅࡓᚋࡢㄗᕪಙྕࡀධຊࡉࢀ㸪₇⟬ࢆ⾜࠸ᾘ㡢ࢫࣆ࣮࢝ࡽ
ఝ㦁㡢ࢆⓎ⏕ࡉࡏ࡚ㄗᕪಙྕࡀᑠࡉࡃ࡞ࡿࡼ࠺ືసࡍࡿ㸬 ANCࢆᐇ⌧ࡍࡿ
ࡣ㸪」㞧࡞ࢹࢪࢱࣝಙྕฎ⌮ࡀᚲせ࡛࠶ࡿࡀ㸪㏆ᖺࡢ༙ᑟయᢏ⾡ࡢ㐍Ṍࡼ
ࡗ࡚㸪MPU(Micro Processing Unit)ࡢฎ⌮ᛶ⬟ࡢྥୖ㸪ᑠᆺ㸪పᾘ㈝㟁ຊ㸪ప
౯᱁ࡀ㐍⾜ࡋ㸪ࢹࢪࢱࣝࢩࢢࢼࣝࣉࣟࢭࢵࢧ(DSP : Digital Signal Processor) ࡀᬑཬࡉࢀࡓࡇࡼࡾᐇ⏝ⓗ࡞ᢏ⾡࡞ࡗ࡚ࡁ࡚࠸ࡿ㸬≉ࢫࢸࣞ࢜࣊ࢵࢻ
࣍ࣥࡣࣀࢬ࢟ࣕࣥࢭࣝᶵ⬟ࡀᦚ㍕ࡉࢀࡓ〇ရࡀᩘከࡃᕷ㈍ࡉࢀ࡚࠸ࡿ㸬ࡓࡔ ࡋ㸪࣊ࢵࢻ࣍ࣥࡘ࠸࡚ࡣᑠࡉ࡞✵㛫࡛ືసࡍࡿࡓࡵ⤒㊰ࡢ㡢㡪≉ᛶࢆ⪃៖ࡋ
࡞ࡃ࡚ࡶືసྍ⬟࡛࠶ࡿࡀ㸪ᕤሙ➼タ⨨ࡋࡓࡢࡼ࠺࡞ࡁ࡞✵㛫࡛ࡣཧ↷
࣐ࢡࣟ࣍ࣥࡽㄗᕪ࣐ࢡࣟ࣍ࣥࡲ࡛ࡢ⤒㊰(㸯ḟ⤒㊰)ࡸᾘ㡢ࢫࣆ࣮࢝ࡽ
ㄗᕪ࣐ࢡࣟ࣍ࣥࡲ࡛ࡢ⤒㊰(㸰ḟ⤒㊰)ࡢ≉ᛶࢆ⪃៖ࡋ࡚ANC ࢩࢫࢸ࣒ࢆᵓ⠏
ࡍࡿᚲせࡀ࠶ࡿ㸬
㸯ḟ⤒㊰㸰ḟ⤒㊰ࢆ⪃៖ࡍࡿᚲせࡀ࠶ࡿANCࢩࢫࢸ࣒࡛ࡣࣇ࣮ࢻࣇ࢛࣡
࣮ࢻไᚚࡢ㐺ᛂࣝࢦࣜࢬ࣒ࡋ࡚Filtered-xࣝࢦࣜࢬ࣒ࡀࡼࡃ⏝ࡉࢀ࡚࠸
ࡿ[6] - [8]㸬ࡋࡋ㸪Filtered-xࣝࢦࣜࢬ࣒ࡣ㸰ḟ⤒㊰ࡢ≉ᛶࡢኚືࡼࡗ࡚ࣔ
ࢹࣝㄗᕪࡀⓎ⏕ࡋไᚚᛶ⬟ࡢຎࡸᏳᐃᛶࡁ࡞ᙳ㡪ࢆ࠼ࡿ[9]㸬ࡇࡢࣔ
ࢹࣝㄗᕪࢆゎᾘࡍࡿࡓࡵ⿵ຓ㞧㡢ὀධἲ[10] - [14]ࡀ࠶ࡿࡀ㸪㸰ḟ⤒㊰ࡢ≉
࠶ࡿ㸬ࡇࢀࡼࡾไᚚࣇࣝࢱࡢ㐺ᛂࣝࢦࣜࢬ࣒⏝࠸ࡿධຊಙྕࡋ࡚㸪㸰 ḟ⤒㊰ࡢఏ㐩㛵ᩘࢆ᭷ࡍࡿࣇࣝࢱࡢ௦ࢃࡾᐃ㐜ᘏࢆస⏝ࡉࡏࡓಙྕࢆ⏝࠸
ࡿࡇࡀྍ⬟࡞ࡾ㸪Ᏻᐃᛶࢆゎᾘࡍࡿ㸬ࡋࡋ㸪 Pre-inverseᆺANCࢩࢫࢸ
࣒࡛ࡣ㸰ḟ⤒㊰ࢆ᥎ᐃࡍࡿ㐺ᛂࣇࣝࢱࡢ᭦᪂ࣝࢦࣜࢬ࣒࡛ồࡵࡿホ౯㛵ᩘ
ࡢ໙㓄እᡂศࡀྵࡲࢀࡿࡇࡼࡾࣂࢫࢆᣢࡗࡓㄗᕪࡀⓎ⏕ࡋ㸪᥎ᐃ
⢭ᗘࡀຎࡋ࡚ࡋࡲ࠺ၥ㢟ࡀ࠶ࡿ㸬᥎ᐃ⢭ᗘࢆྥୖࡉࡏࡿࡓࡵࡣ⏝࠸ࡿ⿵ຓ
㞧㡢ࡢ㟁ຊࢆࡁࡃࡍࡿᚲせࡀ࠶ࡾ㸪ࡇࡢ⿵ຓ㞧㡢ࡀࢩࢫࢸ࣒యࡢ㦁㡢ᡴᾘ ࡋᛶ⬟ࡢຎࢆᘬࡁ㉳ࡇࡋ࡚ࡋࡲ࠺㸬ࡇࡢࡼ࠺࡞ၥ㢟ࢆゎỴࡍࡿࡓࡵ⿵ຓ㞧 㡢ࢆ๐ῶࡍࡿ᪂ࡓ࡞ᡭἲࡀồࡵࡽࢀ࡚࠸ࡿ㸬
1.2 ◊ ◊✲┠ⓗ◊✲ᴫせ
๓⠇࡛㏙ࡓࡼ࠺࡞ᢏ⾡ⓗ⫼ᬒࡢࡶ㸪ᮏㄽᩥ࡛ࡣ㸪㦁㡢ၥ㢟ࢆゎỴࡍࡿࡓ
ࡵࡢᡭẁࡋ࡚Pre-inverseᆺANCࢩࢫࢸ࣒ࡢ᥎ᐃ⢭ᗘᨵၿࢆ┠ⓗࡋ࡚◊✲ࢆ
⾜ࡗࡓ㸬
➨㸰❶࡛ࡣ㸪ࢩࢫࢸ࣒యࡢ᥎ᐃ⢭ᗘຎࢆᘬࡁ㉳ࡇࡍཎᅉ࡞ࡿ⿵ຓ㞧㡢
ࢆ⏝࠸࡞࠸Pre-inverseᆺANCࢩࢫࢸ࣒[21]ࢆᥦࡍࡿ㸬Pre-inverseᆺANCࢩࢫ ࢸ࣒ࢆᵓᡂࡍࡿ࠶ࡓࡾ㸪㸰ḟ⤒㊰ࡢ㏫ఏ㐩㛵ᩘࢆồࡵࡿᚲせࡀ࠶ࡿࡀ㸪㸰ḟ⤒
㊰ࡢఏ㐩㛵ᩘࡣ᭱ᑠ┦⣔ࡣ㝈ࡽ࡞࠸ࡓࡵ㸪༢⣧㸰ḟ⤒㊰ࡢఏ㐩㛵ᩘࢆ᥎ ᐃࡋ࡚ศẕศᏊࢆ㌿ࡋ࡚ࡋࡲ࠺Ⓨᩓࡋ࡚ࡋࡲ࠺ྍ⬟ᛶࡀ࠶ࡿ㸬ࡑࡇ࡛㸪㐺ᛂ ᣦᩘࣇࣝࢱࢆ⏝࠸ࡿࡇ࡛㸪㸰ḟ⤒㊰ఏ㐩㛵ᩘࡢ᭱ᑠ┦㒊᭱┦㒊ࢆ
ศ㞳ࡋ࡚᥎ᐃࢆ⾜࠸㸪ࡑࢀࡒࢀࡢ㏫ఏ㐩㛵ᩘࢆồࡵࡿࡇ࡛Pre-inverseᆺANC
ࢆᵓᡂࡍࡿ㸬ィ⟬ᶵࢩ࣑࣮ࣗࣞࢩࣙࣥࡼࡗ࡚Filtered-xࣝࢦࣜࢬ࣒ẚ㍑ࢆ
⾜࠸ᥦᡭἲࡢ᭷⏝ᛶࢆ☜ㄆࡋ࡚࠸ࡿ㸬
➨㸱❶࡛ࡣ㸪ᚑ᮶◊✲ࡉࢀ࡚ࡁࡓPre-inverseᆺANC࠾࠸࡚㸰ḟ⤒㊰ࡢఏ㐩 㛵ᩘࢆ᥎ᐃࡍࡿ㐺ᛂࣇࣝࢱࡢ᭦᪂ࣝࢦࣜࢬ࣒࡛ồࡵࡿホ౯㛵ᩘࡢ໙㓄እ
ᡂศࡀྵࡲࢀࡿࡇࡼࡾࣂࢫࢆᣢࡗࡓㄗᕪࡀⓎ⏕ࡋ㸪᥎ᐃ⢭ᗘࡀຎ
ࡍࡿၥ㢟╔┠ࡋ㸪ࣂࢫㄗᕪࡀ⌮ㄽୖⓎ⏕ࡋ࡞࠸ᡭἲࢆᥦࡍࡿ[22],[23]㸬 እࣟࣂࢫࢺ࡞ࣝࢦࣜࢬ࣒ࡋ࡚ SSCF(Square Sum of Correlation Function) 㐺ᛂࣝࢦࣜࢬ࣒ࡀᥦࡉࢀ࡚࠸ࡿ[15]㸬SSCF 㐺ᛂࣝࢦࣜࢬ࣒ࡣ㦁㡢※㸰
ࡀ࡛ࡁࡎእࡢᙳ㡪ࢆཷࡅ࡚ࡋࡲ࠺㸬ࡑࡇ࡛㸪ࡇࡢၥ㢟ࢆゎỴࡍࡿࡓࡵ⿵ຓ
ࣇࣝࢱࡼࡿ㸰ḟ⤒㊰㏫ఏ㐩㛵ᩘ᥎ᐃࢆ⏝࠸ࡿPre-inverseᆺANCࢩࢫࢸ࣒ࢆ
ᥦࡍࡿ[19],[20]㸬ᮏᡭἲࡣ㸰ḟ⤒㊰ᑐࡋ࡚⿵ຓࣇࣝࢱࢆ୪ิ㓄⨨ࡋࢩࢫ
ࢸ࣒ྠᐃࢆ⾜࠸㸪⿵ຓࣇࣝࢱᑐࡋ㸪⦪⥆㸰ḟ⤒㊰ࡢ㏫ఏ㐩㛵ᩘࢆ᥎ᐃࡍࡿ
ࣇࣝࢱࢆ㓄⨨ࡍࡿ㸬ࡇࢀࡼࡾ㸰ḟ⤒㊰ࢆ᥎ᐃࡍࡿ㐺ᛂࣇࣝࢱࡢ᭦᪂ࣝ
ࢦࣜࢬ࣒࡛⏝࠸ࡿホ౯㛵ᩘࡢ໙㓄㸪እࡼࡿಙྕᡂศࡀྵࡲࢀ࡞ࡃ࡞ࡿࡓ
ࡵ㸪ࣂࢫㄗᕪࡀ⌮ㄽୖⓎ⏕ࡋ࡞࠸㸬ᚑࡗ࡚㸰ḟ⤒㊰ࡢ᥎ᐃ⏝ࡍࡿ⿵ຓ㞧 㡢ࡢ㟁ຊࢆపῶࡉࡏࡿࡇࡀྍ⬟࡞ࡾ㸪ࢩࢫࢸ࣒యࡢᾘ㡢ᛶ⬟ࢆྥୖࡉࡏ
ࡿࡇࡀྍ⬟࡞ࡿ㸬ࢩ࣑࣮ࣗࣞࢩࣙࣥᐇ㦂࡛ᚑ᮶ἲࡢẚ㍑ࢆ⾜࠸㸪ࡲࡓ㸪ᐇ
ᐇ㦂ࢆ⾜࠺ࡇࡼࡾᥦᡭἲࡀᐇ⎔ቃୗ࡛ືసྍ⬟࡛࠶ࡿࡇࢆ☜ㄆࡋ࡚
࠸ࡿ㸬
᭱ᚋ➨㸲❶࡛ࡣ㸪ࡇࢀࡲ࡛ᚓࡓᡂᯝࢆ⤫ᣓࡋ㸪ᚋṧࡉࢀࡓㄢ㢟ࢆᣦ
ࡋ࡚࠸ࡿ㸬
➨
➨ 2 ❶
⿵ຓ㞧㡢ࢆ⏝࠸࡞࠸ Pre-inverse ᆺ ANC ࢩࢫࢸ࣒
2.1 ⥴ゝ
⌧ᅾ㸪ANC ࢩࢫࢸ࣒࡛ࡣࣇ࣮ࢻࣇ࢛࣮࣡ࢻᆺࡢ㐺ᛂࣝࢦࣜࢬ࣒ࡋ࡚
Filtered-xࣝࢦࣜࢬ࣒ࡀࡼࡃ⏝࠸ࡽࢀ࡚࠸ࡿ[6] - [8]㸬Filtered-xࣝࢦࣜࢬ࣒ࡣ 㸰ḟ㡢※ࢆⓎࡍࡿࢫࣆ࣮࢝ࡽᾘ㡢ຠᯝࡢほ ⏝࠸ࡿㄗᕪ᳨ฟ࣐ࢡࣟ࣍ࣥ
ࡲ࡛ࡢ㡢㡪⣔(㸰ḟ⤒㊰)ࡢఏ㐩㛵ᩘࢆ๓᥎ᐃࡋ㸪ࡑࡢ≉ᛶࢆ᭷ࡍࡿࣇࣝࢱ
㦁㡢ࢆ㏻㐣ࡉࡏࡓಙྕࢆไᚚࣇࣝࢱ࡛࠶ࡿ㐺ᛂࣇࣝࢱ(ADF : Adaptive
Digital Filter)ࡢࢱࢵࣉධຊࡋ࡚⏝࠸ࡿ㸬ࡋࡋ㸪ࡇࡢ๓᥎ᐃࡋࡓ㸰ḟ⤒㊰
ࡢఏ㐩㛵ᩘࡀኚືࡍࡿࡇࡼࡾࣔࢹࣝㄗᕪࡀ⏕ࡌࡿ㸬ࡇࡢࣔࢹࣝㄗᕪࡣ ANC ࢩࢫࢸ࣒ࡢไᚚᛶ⬟ࡢຎࢆᘬࡁ㉳ࡇࡍࡔࡅ࡛࡞ࡃ㸪Ᏻᐃᛶࡁ࡞ᙳ㡪
ࢆ࠼ࡿ[9]㸬ࡑࡇ࡛㸪ࣔࢹࣝㄗᕪࢆ㍍ῶࡍࡿࡓࡵ㸪㸰ḟ⤒㊰ࡢኚື㏣ᚑࡍࡿ
ᡭἲࡋ࡚࡛࢜ࣥࣛࣥ㸰ḟ⤒㊰᥎ᐃࢆ⾜࠺⿵ຓ㞧㡢ὀධἲࡀ࠶ࡿ[10] - [14]㸬
⿵ຓ㞧㡢ὀධἲࡣไᚚࣇࣝࢱࡢฟຊಙྕపࣞ࣋ࣝࡢᗈᖏᇦ⿵ຓಙྕࢆຍ ࡍࡿࡇࡼࡾไᚚືస୰㸰ḟ⤒㊰ࡢఏ㐩㛵ᩘࡢ᥎ᐃࢆ⾜࠺㸬ࡋࡋ࡞ࡀࡽ㸪
ࡇࡢᡭἲ࡛ࡣ㸰ḟ⤒㊰ࡢኚື㏣ᚑࡍࡿࡇࡣྍ⬟࡛࠶ࡿࡀ㸪㏣ᚑࡀ㐜࠸ሙྜ
ࡸ⤒㊰ኚືࡀࡁ࠸ሙྜࢩࢫࢸ࣒ࡀⓎᩓࡋ࡚ࡋࡲ࠺ྍ⬟ᛶࡀ࠶ࡿ㸬
ࡑࡇ࡛㸪Filtered-xࣝࢦࣜࢬ࣒ࢆ⏝ࡋ࡞࠸ ANCࢩࢫࢸ࣒ࡋ࡚Pre-inverse ᆺANCࢩࢫࢸ࣒ࡀᥦࡉࢀ࡚ࡁࡓ[15]㸬Pre-inverseᆺANCࢩࢫࢸ࣒ࡣ㸰ḟ⤒㊰
ࡢ㏫ఏ㐩㛵ᩘࢆ᥎ᐃࡋ㸪ࡑࡢ᥎ᐃ್ࢆ㸰ḟ⤒㊰ࡢ๓ẁࣇࣝࢱࡋ࡚㓄⨨ࡋ㸪 㸰ḟ⤒㊰ࡢไᚚࢆ⾜࠺ࡶࡢ࡛࠶ࡿ㸬ࡇࢀࡼࡾ㦁㡢ไᚚࣇࣝࢱࡣ㸯ḟ⤒㊰ࡢ
ࡳࢆ୪ิᆺࢩࢫࢸ࣒ྠᐃࡋ࡚᥎ᐃࡍࢀࡤࡼ࠸㸬ࡘࡲࡾ㸪Pre-inverse ᆺANCࢩ ࢫࢸ࣒ࡣ㸪㦁㡢ไᚚࣇࣝࢱࡢ㐺ᛂࣝࢦࣜࢬ࣒⏝࠸ࡿධຊಙྕࡋ࡚㸪㸰ḟ
⤒㊰ࡢఏ㐩㛵ᩘࢆ᭷ࡍࡿࣇࣝࢱࡢ௦ࢃࡾᐃ㐜ᘏࢆస⏝ࡉࡏࡓಙྕࢆ⏝࠸ࡿ
ࡇࡼࡾ㸪Ᏻᐃᛶࢆゎᾘࡍࡿ㸬ࡋࡋ㸪Pre-inverse ᆺANCࢩࢫࢸ࣒࡛ࡣ㸰 ḟ⤒㊰ࢆ᥎ᐃࡍࡿ㐺ᛂࣇࣝࢱࡢ᭦᪂ࣝࢦࣜࢬ࣒࡛ồࡵࡿホ౯㛵ᩘࡢ໙㓄
እᡂศࡀྵࡲࢀࡿࡇࡼࡾࣂࢫࢆᣢࡗࡓㄗᕪ㸦௨ୗ㸪ࣂࢫㄗᕪ
ࡪ㸧ࡀⓎ⏕ࡋ㸪᥎ᐃ⢭ᗘࡀຎࡋ࡚ࡋࡲ࠺ၥ㢟ࡀ࠶ࡿ㸬᥎ᐃ⢭ᗘࢆྥୖࡉࡏࡿࡓ
ࡵࡣ⏝࠸ࡿ⿵ຓ㞧㡢ࡢ㟁ຊࢆࡁࡃࡍࡿᚲせࡀ࠶ࡾ㸪ࡇࡢ⿵ຓ㞧㡢ࡀࢩࢫࢸ
࣒యࡢ᥎ᐃ⢭ᗘࡢຎࢆᘬࡁ㉳ࡇࡋ࡚ࡋࡲ࠺㸬
ᮏ❶࡛ࡣ㸪ࡇࡢࢩࢫࢸ࣒యࡢ᥎ᐃ⢭ᗘຎࢆᘬࡁ㉳ࡇࡍཎᅉ࡞ࡿ⿵ຓ㞧 㡢ࢆ⏝ࡋ࡞࠸Pre-inverseᆺANCࢩࢫࢸ࣒ࢆᥦࡍࡿ㸬ࡑࡋ࡚㸪ィ⟬ᶵࢩ࣑ࣗ
࣮ࣞࢩࣙࣥᐇ㦂ࢆ⾜࠸ᥦᡭἲࡢ᭷ຠᛶࢆ☜ㄆࡍࡿ㸬
2.2 ᇶ ᇶᮏཎ⌮
ᮏ⠇࡛ࡣ⿵ຓ㞧㡢ࢆ⏝ࡋ࡞࠸Pre-inverseᆺANCࢩࢫࢸ࣒ࡢᇶᮏཎ⌮ࡘ࠸
࡚ㄝ᫂ࡍࡿ㸬 ᅗ 2. 1ᮏࢩࢫࢸ࣒ࡢᵓᡂࢆ♧ࡍ㸬ྛಙྕࢆ௨ୗ♧ࡍ㸬
) (n
g 㸸㦁㡢
) (n
p 㸸㸯ḟ⤒㊰㏻㐣ᚋࡢ㦁㡢 )
(n
y 㸸ほ ಙྕ
) (n
f 㸸ไᚚಙྕ
) (n
d 㸸㸰ḟ⤒㊰㏻㐣ᚋࡢไᚚಙྕ
)
ec(n ࡣ㐺ᛂࣇࣝࢱHˆSMc (z)㸪HˆSAc (z)ࡢ㐺ᛂࣝࢦࣜࢬ࣒᭦᪂ࡢࡓࡵࡢㄗᕪಙ
ྕ࡛࠶ࡿ㸬
ᅗ 2. 1 ⿵ຓ㞧㡢ࢆ⏝࠸࡞࠸Pre-inverseᆺANCࢩࢫࢸ࣒ᵓᡂᅗ ( )
LMS
( ) Q( )
g( )
( ) ( )
( )
g′ ( ) ( ) ( )
LMS
( ) 㞧㡢※
( ) ′ ( )
ཧ↷䝬䜲䜽 ㄗᕪ䝬䜲䜽
ḟ㡢※
LMS ( )
′ ( )
( )
′( ) ( )
( )
′( )
2.2.1 㸰㸰ḟ⤒㊰ࡢ᥎ᐃ
ᮏ⠇࡛ࡣ⿵ຓ㞧㡢ࢆ⏝࠸࡞࠸Pre-inverseᆺANCࢩࢫࢸ࣒ࡢ㸰ḟ⤒㊰ࡢ᥎ᐃ
ࡘ࠸࡚ㄝ᫂ࡍࡿ㸬ᅗ 2. 2ࡣᥦᡭἲࡢᵓᡂᅗ࡛࠶ࡿᅗ 2. 1ࡽ㸰ḟ⤒㊰ࢆᢳฟ ࡋࡓᅗ࡛࠶ࡿ㸬
ᅗ 2. 2 ⿵ຓ㞧㡢ࢆ⏝࠸࡞࠸Pre-inverseᆺANCࢩࢫࢸ࣒ࡢ㸰ḟ⤒㊰ᵓᡂᅗ
( )
Q( )
( )
g′ ( )
( )
( )
LMS ′( ) ′ ( )
ㄗᕪ䝬䜲䜽
ḟ㡢※
′ ( )
LMS
㸰ḟ⤒㊰ࡢఏ㐩㛵ᩘHS(z)ࡣ୍⯡ⓗ᭱┦㒊᭱ᑠ┦㒊ศࡅࡿࡇ
ࡀྍ⬟࡛࠶ࡾ㸪ḟᘧ࡛⾲ࡉࢀࡿ㸬
) ( ) ( )
(z H z H z
HS SM SA 㸦 2.1 㸧
ࡇࡇ࡛㸪HSM(z)㸪HSA(z)ࡣࡑࢀࡒࢀ㸰ḟ⤒㊰ࡢ᭱ᑠ┦㒊㸪᭱┦㒊ࡢఏ㐩 㛵ᩘ࡛࠶ࡿ㸬㸰ḟ⤒㊰ࡢ᭱ᑠ┦㒊ࡢ㏫ఏ㐩㛵ᩘࢆ᥎ᐃࡍࡿᣦᩘᆺ㐺ᛂࣇࣝ
ࢱHˆSMc (z)ࡣḟᘧ࡛࠼ࡽࢀࡿ㸬
¦
c
N k
k k SM
z n g z
G
z G z
H
1
) ( )
(
) ( exp ) ˆ (
㸦 2.2 㸧
) (z
G ࡣࢺࣛࣥࢫࣂ࣮ࢧࣝᆺࡢࣇࣝࢱ࡛࠶ࡾ㸪N ࡣG(z)ࡢࢱࢵࣉᩘ㸪gk(n)ࡣ )
(z
G ࡢk␒┠ࡢࢱࢵࣉಀᩘ࡛࠶ࡿ㸬᭦᪂ࣝࢦࣜࢬ࣒ࡣ
>
( ) ( )@
) ( ) 1
(n g n Ee n d n k
gk k D c 㸦 2.3 㸧
࡞ࡿ㸬ࡇࡇ࡛㸪Dࡣ㐺ᛂࣇࣝࢱࡢࢫࢸࢵࣉࢧࢬ࡛࠶ࡾ㸪E
> @
ࡣ㞟ྜᖹᆒ࡛࠶ࡿ㸬ᣦᩘᆺ㐺ᛂࣇࣝࢱHˆSMc (z)ࡣࡍ࡚ࡢᴟ㞽Ⅼࡀ༢ෆᏑᅾࡍࡿࡓ
ࡵ[16]㸪ᚲࡎ᭱ᑠ┦ఏ㐩㛵ᩘ࡞ࡿ㸬ᣦᩘᆺ㐺ᛂࣇࣝࢱHˆSMc (z)ࡣ࣐ࢡ࣮ࣟࣜ
ࣥᒎ㛤ࡼࡗ࡚ḟᘧࡢࡼ࠺㏆ఝࡉࢀࡿ㸬
( ) /2! ( ) / !) ( 1 )
ˆ (z G z G z 2 G z r
HSMc r 㸦 2.4 㸧
ࡇࡇ࡛㸪rࡣ㏆ఝࡢ㡯ᩘ࡛࠶ࡿ㸬ᣦᩘᆺ㐺ᛂࣇࣝࢱHˆSMc (z)ࡢᵓᡂᅗࢆᅗ 2. 3
♧ࡍ㸬
ᅗ 2. 3 HˆSMc (z)ᵓᡂᅗ
1
z
Adaptive Algorithm
1
z z1
1
z z1 z1
1/2!
1/r!
1
z z1 z1
) (n q
)
2(n
g gN1(n) gN(n)
) (n f )
1(n g
)
2(n
g gN1(n) gN(n) )
1(n g
)
2(n
g gN1(n) gN(n) )
1(n g
㸰ḟ⤒㊰ࡢ᭱┦㒊ࢆ᥎ᐃࡍࡿࢺࣛࣥࢫࣂ࣮ࢧࣝᆺࡢ㐺ᛂࣇࣝࢱHˆSAc (z) ࡣḟᘧ࡛⾲ࡉࢀࡿ㸬
M j j
j
SA z w n z
Hc
¦
0
) ( )
ˆ ( 㸦 2.5 㸧
ࡇࡇ࡛㸪M ࡣHˆSAc (z)ࡢࢱࢵࣉᩘ࡛࠶ࡾ㸪wj(n)ࡣHˆSAc (z)ࡢ j␒┠ࡢࢱࢵࣉಀᩘ࡛
࠶ࡿ㸬᭦᪂ࣝࢦࣜࢬ࣒ࡣ
>
( ) ( )@
) ( ) 1
(n w n E e n q n j
wj j E c 㸦 2.6 㸧
࡞ࡿ㸬ࡇࡇ࡛㸪Eࡣ㐺ᛂࣇࣝࢱࡢࢫࢸࢵࣉࢧࢬ࡛࠶ࡾ㸪E
> @
ࡣ㞟ྜᖹᆒ࡛࠶ࡿ㸬㐺ᛂࣇࣝࢱHˆSAc (z)ࡢᵓᡂࢆᅗ 2. 4♧ࡍ㸬
ᅗ 2. 4 HˆSAc (z)ᵓᡂᅗ
1
z z1 z1
) (n q
w2 wM1 wM
w1
w0
) (n a
ᅗ 2. 5 HˆSMc (z)HˆSAc (z)ࡢ᥎ᐃࡢಙྕࡢὶࢀ
㸰ḟ⤒㊰᭱ᑠ┦㒊ࡢ㏫ఏ㐩㛵ᩘࢆ᥎ᐃࡍࡿᣦᩘᆺ㐺ᛂࣇࣝࢱHˆSMc (z) 㸰ḟ⤒㊰᭱┦㒊ࢆ᥎ᐃࡍࡿ㐺ᛂࣇࣝࢱHˆSAc (z)ࡢ᥎ᐃࡢືసࡘ࠸࡚ㄝ᫂
ࢆ⾜࠺㸬ᅗ 2. 5HˆSMc (z)HˆSAc (z)ࡢ᥎ᐃࡢಙྕࡢὶࢀࢆ♧ࡍ㸬HˆSMc (z)ࡣಙ
ྕq(n)ࢆ⏝ࡋ࡚┤ิᆺࡢࢩࢫࢸ࣒ྠᐃࡋ࡚HSM(z)ࡢ㏫ఏ㐩㛵ᩘ࡛࠶ࡿ
) ( /
1 HSM z ࡢ᥎ᐃࢆ⾜࠺㸬୍᪉㸪HˆSAc (z)ࡣಙྕq(n)ࢆ⏝ࡋ࡚୪ิᆺࡢࢩࢫࢸ࣒
ྠᐃࡋ࡚HSA(z)ࡢ᥎ᐃࢆ⾜࠺㸬
( )
Q( )
( )
g′ ( )
( )
( )
LMS ′( ) ′ ( )
ㄗᕪ䝬䜲䜽
ḟ㡢※
′ ( )
LMS ( )
( )
)
( )
)
′
㸰ḟ⤒㊰ఏ㐩㛵ᩘࡢ᭱┦㒊ࡢ㏫ఏ㐩㛵ᩘ࡛࠶ࡿQ(z)ࡣḟᘧ࡛⾲ࡉࢀࡿ㸬
¦
c
V q
q q
SA M V
z n b
z H z
z Q
0
) 1 (
) (
) ˆ ( )
(
㸦 2.7 㸧
VࡣQ(z)ࡢࢱࢵࣉᩘ࡛࠶ࡾ㸪bq(n)ࡣQ(z)ࡢq␒┠ࡢࢱࢵࣉಀᩘ࡛࠶ࡿ㸬᭱
┦ఏ㐩㛵ᩘࡢ㏫ఏ㐩㛵ᩘࡣᅉᯝᛶࢆ‶ࡓࡉ࡞࠸ࡓࡵ㸪༢⣧ಀᩘࢆ㌿ࡉࡏ࡚
㏫ࣇࣝࢱࢆᵓᡂࡍࡿࢩࢫࢸ࣒ࡀⓎᩓࡋ࡚ࡋࡲ࠺㸬ࡑࡇ࡛㸪㐜ᘏࢆᤄධࡍࡿࡇ
ࡼࡾ㏫ఏ㐩㛵ᩘQ(z)ࢆᐇ⌧ࡍࡿ㸬
㐺ᛂࣇࣝࢱHˆSAc (z)ࡣ᭱┦㒊ࡢఏ㐩㛵ᩘࢆ᥎ᐃࡍࡿ㐺ᛂࣇࣝࢱࡢࡓࡵ㸪 ᥎ᐃᚋࡢఏ㐩㛵ᩘ ˆ ( )
, z
HOcSA ࡢఏ㐩㛵ᩘࡢ㞽Ⅼࡣࡍ࡚༢እᏑᅾࡍࡿ㸬ࡼࡗ
࡚
HˆOc,SA(z)1ࡢᴟࡣࡍ࡚༢እᏑᅾࡋ㸪ࡑࡢࣥࣃࣝࢫᛂ⟅[(m)ࡣ้0
m ࡢࡳᏑᅾࡍࡿࡇ࡞ࡾ㸪┤᥋⟬ฟࡍࡿࡇࡣྍ⬟࡛࠶ࡿ㸬㸪S(z)
ࢆ㸪
) ˆ (
)
( 1
,
c z
H z z S
SA O
M
㸦 2.8 㸧
ᐃ⩏ࡍࢀࡤ㞽Ⅼࡣࡍ࡚༢ෆᏑᅾࡍࡿࡓࡵ㸪ࡑࡢ㏫zኚ
¦
Vi si m i
m s
0
) ( )
( G 㸦2.9 㸧
ࡣ⟬ฟྍ⬟࡛࠶ࡿ㸬ࡲࡓ㸪
¦
Vi si m i
m v
0
) ( )
( G 㸦 2.11 㸧
ࡋ࡚⟬ฟྍ⬟࡛࠶ࡿ㸬ࡇࡇ࡛v(m)ࡣᅉᯝᛶࢆ‶ࡓࡉ࡞࠸ࡓࡵ㸪㐜ᘏV ࢆᤄධ ࡍࡿࡇࡼࡾ㸪
¦
V
i si m i V
V m v
0
) (
)
( G 㸦 2.12 㸧
ࡋ࡚ᐇ⌧ࡍࡿ㸬ࡍ࡞ࢃࡕ㸪
) ) (
(
, ) 1 (
z H z z
S z
A O
M
V V
㸦 2.13 㸧
࡛࠶ࡾ㸪┠ⓗࡍࡿ[(m)ᑐࡋ㸪(M V)ࡢ㐜ᘏಙྕࢆᤄධࡋࡓ[(mM V) ࡋ࡚ᐇ⌧ྍ⬟࡛࠶ࡿ㸬ᅗ 2. 6 s(m)ࡢ⟬ฟᅇ㊰ࢆ㸪ᅗ 2. 7 s(m)㸪v(m)㸪
) (m V
v ࡢ㛵ಀᛶࢆᅗ♧ࡍࡿ㸬
ᅗ 2. 6 s(m)⟬ฟᅇ㊰
1
z
1
z
1
z
)
G(m (wO,M)1
1 ,M
wO
1 ,
wO
0 ,
wO
) (m s )
(z S
m
0 m ) (m
v s(m)
( ))
(m V m M V
v [
V
) ˆ (z
HSMc 㸪HˆSAc (z)ࡀ᭱㐺ゎ᮰ࡋࡓሙྜ㸪㸰ḟ⤒㊰ఏ㐩㛵ᩘࡑࡢ㏫ఏ㐩㛵
ᩘ࡛࠶ࡿQ(z)㸪HˆSMc (z)㸪HˆSAc (z)㸪HSA(z)࡛ᵓᡂࡉࢀࡿఏ㐩㛵ᩘHT(z)ࡣḟᘧ
࡞ࡿ㸬
) (
) ( ) ( ) ˆ ( ) ( ) (
M V
SA SM
SM T
z
z H z H z H z Q z H
c 㸦 2.14 㸧
ࡼࡗ࡚㸪
)) (
( )
(n g n V M
d Cc 㸦 2.15 㸧
࡛࠶ࡾ㸪㸰ḟ⤒㊰ࡢฟຊd(n)ࡣ㸰ḟ⤒㊰ࡢධຊgCc(n)ࡢ㐜ᘏಙྕ࡞ࡿ㸬
2.2.2 㸯㸯ḟ⤒㊰ࡢ᥎ᐃ
ᅗ 2. 8ࡣ㸰ḟ⤒㊰ࡀ᭱㐺್᮰ࡋࡓሙྜࡢᵓᡂᅗ࡛࠶ࡿ㸬㸯ḟ⤒㊰ࢆ᥎ᐃ
ࡍࡿไᚚࣇࣝࢱHˆCc (z)ࡣࢺࣛࣥࢫࣂ࣮ࢧࣝᆺࡢ㐺ᛂࣇࣝࢱ࡛࠶ࡾ㸪ḟᘧ࡛
࠼ࡽࢀࡿ㸬
F i
i i
C z p n z
H
¦
0
) ( )
ˆ ( 㸦 2.16 㸧
ࡇࡇ࡛㸪F ࡣHˆC(z)ࡢࢱࢵࣉᩘ࡛࠶ࡾ㸪pi(n)ࡣHˆC(z)ࡢi␒┠ࡢࢱࢵࣉಀᩘ࡛࠶
ࡿ㸬᭦᪂ࣝࢦࣜࢬ࣒ࡣ
>
( ) ( )@
) ( ) 1
(n p n Ee2 n g n i
pi i
J
c 㸦 2.17 㸧࡞ࡿ㸬ࡇࡇ࡛㸪J ࡣ㐺ᛂࣇࣝࢱࡢࢫࢸࢵࣉࢧࢬ࡛࠶ࡾ㸪E
> @
ࡣ㞟ྜᖹᆒ࡛࠶ࡿ㸬ࢩࢫࢸ࣒ࡢฟຊ࡛࠶ࡿy(n)ࡣ㸪
) ( ) ( )
(n p n d n
y 㸦 2.18 㸧
࡛࠶ࡿ㸬
㐺ᛂࣇࣝࢱHˆC(z)ࡣ୪ิᆺࡢࢩࢫࢸ࣒ྠᐃࡼࡗ࡚HP(z)zVMࢆ᥎ᐃࡍ
ࡿࡇ࡞ࡾ㸪㦁㡢 p(n)ࡣd(n)ࡼࡾᢚᅽࡉࢀ㸪㦁㡢ࡀᡴࡕᾘࡉࢀࡽࢀࡿ㸬
ᅗ 2. 8 㸰ḟ⤒㊰᮰ࡢࣈࣟࢵࢡᅗ ( )
LMS ( )
g( )
( ) ( )
( )
g′ ( ) 㞧㡢※
ཧ↷䝬䜲䜽 ㄗᕪ䝬䜲䜽
ḟ㡢※ ( )
( )
( )
2.2.3 㸯㸯ḟ⤒㊰㸰ḟ⤒㊰ྠ᥎ᐃࡢၥ㢟Ⅼ
๓⠇ࡲ࡛㸯ḟ⤒㊰㸰ḟ⤒㊰ࡢ᥎ᐃ᪉ἲࡘ࠸࡚㏙ࡓ㸬㸰ḟ⤒㊰ࡢࡳ࡛
᥎ᐃࡍࡿሙྜၥ㢟࡞ࡽ࡞ࡗࡓࡀ㸪㸯ḟ⤒㊰ྜࢃࡏ࡚ࢩࢫࢸ࣒య࡛᥎ᐃ
ࢆ⾜࠺ሙྜ㸪㸰ḟ⤒㊰ࡢ㐺ᛂࣝࢦࣜࢬ࣒ධຊࡍࡿㄗᕪಙྕec(n)p(n)ࢆྵ
ࢇ࡛ࡋࡲ࠺㸬ࡇࡢࡢㄗᕪಙྕec(n)ࡣ
) ( ) ( ) ( )
(n y n a n p n
ec 㸦 2.19 㸧
࡞ࡿ㸬㸰ḟ⤒㊰ࡢ㐺ᛂࣝࢦࣜࢬ࣒ࡗ࡚p(n)ࡣእ࡞ࡿࡓࡵ㸪㸰ḟ⤒
㊰ࡢ᥎ᐃࡀṇࡋࡃ⾜ࢃࢀ࡞࠸㸬ࡑࡇ࡛㸪
) ( ) ( ) ( ) ( )
(n y n a n p n p n
ec c 㸦 2.20 㸧
ࡋ㸪p(n)ࡢᙳ㡪ࢆpc(n)࡛┦ẅࡍࡿࡇ࡛㸰ḟ⤒㊰ࡢ᥎ᐃ⢭ᗘࡀྥୖࡋ㸪⿵ຓ
㞧㡢ࢆ⏝ࡍࡿࡇ࡞ࡃ᭱㐺್᥎ᐃࡍࡿࡇࡀྍ⬟࡞ࡿ㸬
2.3 ィ ィ⟬ᶵࢩ࣑࣮ࣗࣞࢩࣙࣥ
ᮏ⠇࡛ࡣ㸪ᥦᡭἲࡢ㦁㡢ᢚᅽຠᯝࢆ☜ㄆࡍࡿࡓࡵ㸪ィ⟬ᶵࡼࡿࢩ࣑ࣗࣞ
࣮ࢩࣙࣥᐇ㦂ࢆ⾜࠺㸬
ᮏࢩ࣑࣮ࣗࣞࢩࣙࣥᐇ㦂࠾࠸࡚㸪㦁㡢※g(n)ࡋ࡚ᖹᆒ್ࡀ㞽ࡢⓑⰍᛶ࢞
࢘ࢫ㞧㡢ࢆ⏝࠸ࡓ㸬
ᮍ▱ࡢ⤒㊰ࡋ࡚㸪㸯ḟ⤒㊰ࡢఏ㐩㛵ᩘHP(z)ࡣ㸪
12 , 2
) (
)
( ( ) *0 1* 1 2* 2 V
M
z p z p p z
z
HP V M
㸦 2.21 㸧
࡛࠼ࡽࢀࡿ㸬ࡲࡓ㸪㸰ḟ⤒㊰ࡢ᭱ᑠ┦㒊ఏ㐩㛵ᩘHSM(z)᭱┦㒊ఏ㐩 㛵ᩘHSA(z)ࡣ㸪
6 / ,
5 . 1 , cos 2 ,
) (
* 1 2
* 0
2 1
* 1
* 0
S T T
R R
a R a
z z a a z HSA
㸦 2.22 㸧
¦
|
5
1
*
*
* 2
*
*
*
) (
8
,
! / )) ( (
! 2 / )) ( ( ) ( 1
)) ( exp(
) (
i
i i
r M
S
z g z
G r
r z G z
G z G
z G z
H
㸦 2.23 㸧
࡛࠼ࡽࢀࡿ㸬ᮏࢩ࣑࣮ࣗࣞࢩ࡛ࣙࣥࡣ⤒㊰ኚືᑐࡍࡿホ౯ࢆ⾜࠺ࡓࡵ㸪ࢩ࣑
࣮ࣗࣞࢩࣙࣥ㛤ጞࡽࡢヨ⾜ࣈࣟࢵࢡᅇᩘl=1500࡛⤒㊰ࢆኚືࡉࡏࡿ㸬⾲g*i㸪
*
pi ࡢタᐃ್ࢆ♧ࡍ㸬
⾲ 2.1 G*(z)HP(z)ࡢタᐃ್
Number of blocks, l
)
*(z
G HP(z)
*
g1 g*2 g3* g*4 g5* p*0 p1* p2* 0 - 1499 0.5 0.5 0.3 -0.5 0.1 1.0 1.0 1.0 1500 - 3000 -0.5 0.5 0.3 -0.5 0.1 1.0 -1.0 1.0
㐺ᛂࣇࣝࢱHˆSMc (z)㸪HˆSAc (z)㸪HˆC(z)ࡢࢱࢵࣉಀᩘࡢ᭦᪂⏝࠸ࡿ㐺ᛂࣝ
ࢦࣜࢬ࣒ࡣḟᘧ࡛♧ࡍblock normalized least mean square(BNLMS)[17]ࣝࢦࣜࢬ
࣒ࢆ⏝ࡍࡿ㸬
> @
¦ ¦
¦
c
N
m L l
lL n L l
lL n k
k
m n e
k n e n e l
g l
g
0 1 ) 1
( 2
1 1 ) 1 (
1
) (
)) ( ) ( ( )
( ) 1 (
D
㸦 2.24 㸧
> @
¦ ¦
¦
c
M
m L l
lL n
L l
lL n j
j
m n e
j n e n e l
w l
w
0 1 ) 1
( 2
1 1 ) 1 (
1
) (
)) ( ) ( ( )
( ) 1 (
E
㸦 2.25 㸧
> @
¦ ¦
¦
F l L
L l
lL n i
i
m n y
i n y n e l
p l
p ( 1) 1
2 1
) 1 (
2
) (
) ( ) ( )
( ) 1 (
J
㸦 2.26 㸧
ᮏࢩ࣑࣮ࣗࣞࢩࣙࣥ࠾࠸࡚㸪㐺ᛂࣇࣝࢱHˆSMc (z)㸪HˆSAc (z)㸪HˆC(z)ࡢึᮇ
್ࡣHˆC(z)ࡢࢱࢵࣉಀᩘp0(0) 1ࡋ㸪ࡑࡢࡢࢱࢵࣉಀᩘࡣࡍ࡚0ࡋࡓ㸬 ᥦᡭἲࡢᛶ⬟ࢆホ౯ࡍࡿࡓࡵ㸪ࢡࢸࣈࣀࢬࢥࣥࢺ࣮ࣟࣝࢩࢫࢸ࣒
ࡋ࡚ࡼࡃ⏝࠸ࡽࢀࡿ⿵ຓ㞧㡢ࢆ⏝ࡋࡓFiltered-xࣝࢦࣜࢬ࣒ẚ㍑ࢆ⾜࠺㸬
Filtered-xࣝࢦࣜࢬ࣒ࡢᵓᡂᅗࢆᅗ 2. 9♧ࡍ㸬ྛ㐺ᛂࣇࣝࢱࡢ᭦᪂ࣝࢦ
ࣜࢬ࣒ࡣᥦᡭἲྠᵝBNLMSࣝࢦࣜࢬ࣒ࢆ⏝ࡍࡿ㸬
ᅗ 2. 9 Filtered-xࣝࢦࣜࢬ࣒
( )
( )
LMS ′ ( )
( ) g( )
( ) ( )
( )
g′ ( ) ( )
LMS ′( )
㞧㡢※
( )
ཧ↷䝬䜲䜽 ㄗᕪ䝬䜲䜽
ḟ㡢※
( )
ᮏࢩ࣑࣮ࣗࣞࢩࣙࣥࡢタᐃ್ࢆ⾲ 2.2♧ࡍ㸬
⾲ 2.2 ࢩ࣑࣮ࣗࣞࢩࣙࣥタᐃ್
Filtered-x
ࣝࢦࣜࢬ࣒
ᥦᡭἲ
) ˆ (z
HC ࡢࢱࢵࣉᩘ 16 16
) ˆ (z
HC ࡢࢫࢸࢵࣉࢧࢬJ 0.5 0.5
) (z
G ࡢࢱࢵࣉᩘ 16
) ˆ (z
HSMc ࡢࢫࢸࢵࣉࢧࢬD 0.5
) ˆ (z
HSAc ࡢࢱࢵࣉᩘ 3
) ˆ (z
HSAc ࡢࢫࢸࢵࣉࢧࢬE 0.1
) (z
Q ࡢࢱࢵࣉᩘ 12
) (z
A ࡢࢱࢵࣉᩘ 40
) (z
A ࡢࢫࢸࢵࣉࢧࢬ 0.5
ࣈࣟࢵࢡ㛗L 128 128
ࣀࢬ㝖ཤᛶ⬟ࡢホ౯ࡍࡿࡓࡵḟᘧ♧ࡍ㦁㡢ᡴᾘࡋ⢭ᗘEV(l)ࢆᐃ⩏ࡍࡿ㸬
] [ ) (
) ( log
10 )
( ( 1) 1
2 1 ) 1
( 2
10 dB
n p E
n y E
l
EV l L
lL n
L l
lL n
»¼
« º
¬ ª
»¼
« º
¬ ª
¦
¦
㸦 2.27 㸧
ࡇࡇ࡛㸪y(n)ࡣFiltered-xࣝࢦࣜࢬ࣒ࡢሙྜ㸪⿵ຓ㞧㡢ࡢᡂศࢆྵࡲ࡞࠸ಙྕ
࡛࠶ࡿ㸬ᮏࢩ࣑࣮ࣗࣞࢩ࡛ࣙࣥࡣ⊂❧࡞ 200 ᅇࡢヨ⾜⧞ࡾ㏉ࡋ㸪ᖹᆒࢆࡗ࡚
EV(l)ࢆồࡵࡓ㸬
ᅗ 2. 10 ᮏࢩ࣑࣮ࣗࣞࢩࣙࣥᐇ㦂ࡢ⤖ᯝࢆ♧ࡍ㸬ᐇ⥺ࡀᥦᡭἲ㸪◚⥺ࡀ
Filtered-x ࣝࢦࣜࢬ࣒ࡢ EV(l)ࢆ♧ࡋ࡚࠸ࡿ㸬ᥦᡭἲࡣ Filtered-x ࣝࢦࣜࢬ
࣒ẚ㍑ࡋ࡚ᾘ㡢ᛶ⬟࡛࠶ࡿ EV(l)ࡀ⣙-25dB ᨵၿࡉࢀ࡚࠸ࡿ㸬ࡲࡓ㸪ヨ⾜ࣈࣟ
ࢵࢡᅇᩘ l=1500࡚㸯ḟ⤒㊰࠾ࡼࡧ㸰ḟ⤒㊰ࡢఏ㐩㛵ᩘࢆኚࡉࡏࡓᚋࡶ㸪ᥦ
ᡭἲࡣ㠀ᐃᖖ࡞⤒㊰㏣ᚑྍ⬟࡛࠶ࡿࡢᑐࡋ㸪Filtered-x ࣝࢦࣜࢬ࣒ࡣ㏣
ᚑྍ⬟࡛࠶ࡿ㸬
ᅗ 2. 10 ࢩ࣑࣮ࣗࣞࢩࣙࣥ⤖ᯝ
0 1000 2000 3000
-50 -40 -30 -20 -10 0
Number of blocks, l
EV ( l ) [dB]
ᥦἲFiltered-x
ࣝࢦࣜࢬ࣒
2.4 ⤖ ⤖ゝ
ᮏ❶࡛ࡣ㸪⿵ຓ㞧㡢ࢆ⏝࠸࡞࠸Pre-inverseᆺANCࢩࢫࢸ࣒ࢆᥦࡋ㸪ィ⟬ᶵ ࢩ࣑࣮ࣗࣞࢩ࡛ࣙࣥᮏᡭἲࡢ᭷ຠᛶࢆ☜ㄆࡋࡓ㸬
ᮏᡭἲࡣ㸪㸰ḟ⤒㊰ࡢ㏫ఏ㐩㛵ᩘࢆ᥎ᐃࡍࡿࡓࡵ㸪㐺ᛂᣦᩘࣇࣝࢱࢆ⏝࠸
࡚᭱ᑠ┦㒊᭱┦㒊ศゎࡋ࡚᥎ᐃࢆ⾜࠸㸪ࡑࢀࡒࢀᑐࡋ࡚㏫ఏ㐩㛵
ᩘࢆィ⟬ࡍࡿᡭἲ࡛࠶ࡿ㸬ィ⟬ᶵࢩ࣑࣮ࣗࣞࢩࣙࣥᐇ㦂࠾࠸࡚ࡣ㸪ࣇ࣮ࢻࣇ
࢛࣮࣡ࢻᆺࡢ ANC ࢩࢫࢸ࣒ࡋ࡚ࡼࡃ⏝࠸ࡽࢀࡿ Filtered-x ࣝࢦࣜࢬ࣒ࡢ ᥎ᐃ⢭ᗘ⤒㊰ኚືᑐࡍࡿ㏣ᚑᛶ⬟ࡢẚ㍑ࢆ⾜࠸㸪⢭ᗘࡢྥୖ⤒㊰ኚື
ࡢ㏣ᚑᛶ⬟ྥୖࢆ☜ㄆ࡛ࡁ㸪ᮏᡭἲࡢ᭷ຠᛶࡀ♧ࡉࢀࡓ㸬
➨
➨ 3 ❶
⿵ຓࣇࣝࢱࡼࡿ㸰ḟ⤒㊰㏫ఏ㐩㛵ᩘ
᥎ᐃࢆ⏝࠸ࡿ Pre-inverse ᆺ ANC ࢩࢫࢸ࣒
3.1 ⥴ゝ
๓❶࡚ㄝ᫂ࡋࡓ⿵ຓ㞧㡢ࢆ⏝࠸࡞࠸Pre-inverseᆺANCࢩࢫࢸ࣒ࡣ㸰ḟ⤒㊰
㏫ఏ㐩㛵ᩘࢆồࡵࡿࡓࡵ㸪㸰ḟ⤒㊰ࡢ᭱┦㒊᭱ᑠ┦㒊ࢆศ㞳ࡋ࡚᥎ ᐃࡋ㸪ࡑࢀࡒࢀࡢ㏫ఏ㐩㛵ᩘࢆồࡵࡿࡇ࡛ANCࢩࢫࢸ࣒ࢆᐇ⌧ࡋࡓ㸬ࢩ࣑ࣗ
࣮ࣞࢩࣙࣥᐇ㦂࡛Filtered-xࣝࢦࣜࢬ࣒ẚ㍑ࢆ⾜࠸ᥦᡭἲࡢ᭷ຠᛶࡀ☜ㄆ
࡛ࡁࡓ㸬ࡋࡋ㸪ࢩ࣑࣮ࣗࣞࢩࣙࣥᐇ㦂࡛ࡣᮍ▱ࡢ㸰ḟ⤒㊰ࡢఏ㐩㛵ᩘࢆ᭱
┦㒊᭱ᑠ┦㒊ศ㞳ࡋࡓࡶࡢࢆ⏝ࡋࡓࡀ㸪ࡼࡾᐇ⎔ቃ㏆࠸⤒㊰࡛ࡢࢩ
࣑࣮ࣗࣞࢩࣙࣥᐇ㦂ࢆ⾜ࡗࡓࡇࢁṇᖖືసࡋ࡞࠸ၥ㢟ࡀ⏕ࡌࡓ㸬ࡇࢀࡣ㸪㸰 ḟ⤒㊰ࡢ᭱ᑠ┦㒊ࢆ᥎ᐃࡍࡿ㐺ᛂᣦᩘࣇࣝࢱࡀṇ☜᥎ᐃ࡛ࡁ࡞ࡗࡓࡓ
ࡵ᭱┦㒊ࢆ᥎ᐃࡍࡿ㐺ᛂࣇࣝࢱࡀ᭱ᑠ┦㒊ࢆྵࢇࡔఏ㐩㛵ᩘࢆ᥎ᐃ ࡋ࡚ࡋࡲ࠸㸪ࡑࡢ㏫ఏ㐩㛵ᩘࢆồࡵࡿᅉᯝᛶࢆ‶ࡓࡏ࡞ࡃ࡞ࡗ࡚ࡋࡲࡗࡓࡓ
ࡵࢩࢫࢸ࣒ࡀⓎᩓࡋ࡚ࡋࡲࡗࡓ⪃࠼ࡽࢀࡿ㸬㐺ᛂᣦᩘࣇࣝࢱࡀṇࡋࡃ᥎ ᐃ࡛ࡁ࡞ࡗࡓཎᅉࡋ࡚㸪㸰ḟ⤒㊰ࡢ᭱ᑠ┦㒊ࢆᣦᩘࣇࣝࢱ࡛⌧࡛ࡁ
࡞ࡗࡓࡇࡸ㸪⿵ຓ㞧㡢ࢆ⏝ࡋ࡚࠸࡞࠸ࡓࡵ㸰ḟ⤒㊰ࡢ᥎ᐃ⏝ࡍࡿಙ
ྕࡀ᭷Ⰽࡋ࡚ࡋࡲࡗࡓࡇࡼࡿ᥎ᐃ⢭ᗘࡢຎࡀ⪃࠼ࡽࢀࡿ㸬
ࡑࡇ࡛㸪ᮏ❶࡛ࡣ᪂ࡓ࡞Pre-inverseᆺANCࢩࢫࢸ࣒ࡢᥦࢆ⾜࠺㸬Pre-inverse ᆺANCࢩࢫࢸ࣒࡛ࡣ๓㏙ࡢ㏻ࡾእࡼࡿࣂࢫㄗᕪࡢᙳ㡪࡛᥎ᐃ⢭ᗘࡀຎ
ࡋ࡚ࡋࡲ࠺ၥ㢟ࡀ࠶ࡗࡓ㸬ࡑࡇ࡛㸪እࣟࣂࢫࢺ࡞㐺ᛂࣝࢦࣜࢬ࣒ࡋ࡚
SSCF(Square Sum of Correlation Function)㐺ᛂࣝࢦࣜࢬ࣒ࡀᥦࡉࢀ࡚࠸ࡿ[15]㸬 SSCF 㐺ᛂࣝࢦࣜࢬ࣒ࡣ㦁㡢※㸰ḟ⤒㊰ࢆ᥎ᐃࡍࡿࡓࡵຍࡍࡿ⿵ຓ㞧 㡢ࡀ⊂❧ᛶࡼࡾ↓┦㛵࡛࠶ࡿᛶ㉁ࢆ⏝ࡋ㸪⿵ຓ㞧㡢ㄗᕪಙྕࡢ┦┦㛵 㛵ᩘࢆホ౯㛵ᩘࡍࡿࡇࡼࡾ㸪እࡢᙳ㡪ࢆᢚ࠼ࡓ㸰ḟ⤒㊰᥎ᐃࢆྍ⬟
ࡍࡿ㸬ࡋࡋ㸪┿ࡢ┦┦㛵㛵ᩘࢆィ⟬ࡍࡿࡓࡵࡣ㛗㛫 ᐃࡀᚲせ࡛࠶ࡾ㸪 ᐇ⏝ୖࣂࢫㄗᕪࢆᢚᅽࡍࡿࡇࡀ࡛ࡁࡎ㸪እࡢᙳ㡪ࢆཷࡅ࡚ࡋࡲ
࠺㸬ࡇࡢၥ㢟ࢆゎỴࡍࡿࡓࡵ㸪⿵ຓࣇࣝࢱࡼࡿ㸰ḟ⤒㊰㏫ఏ㐩㛵ᩘ᥎ᐃࢆ
⏝࠸ࡿPre-inverseᆺANCࢩࢫࢸ࣒ࢆᥦࡍࡿ㸬ᮏᡭἲࡣ㸪㸰ḟ⤒㊰ᑐࡋ⿵ຓ
ࣇࣝࢱࢆ୪ิ㓄⨨ࡋࢩࢫࢸ࣒ྠᐃࢆ⾜࠸㸪⿵ຓࣇࣝࢱᑐࡋ⦪⥆㸰ḟ
⤒㊰ࡢ㏫ఏ㐩㛵ᩘࢆ᥎ᐃࡍࡿࣇࣝࢱࢆ㓄⨨ࡍࡿ㸬ࡇࢀࡼࡾ㸰ḟ⤒㊰ࢆ᥎ᐃ ࡍࡿ㐺ᛂࣇࣝࢱࡢ᭦᪂ࣝࢦࣜࢬ࣒࡛ồࡵࡿホ౯㛵ᩘࡢ໙㓄እࡼࡿಙ
ྕᡂศࢆྵࡲ࡞࠸ᅇ㊰ᵓᡂ࡞ࡿࡓࡵ㸪ࣂࢫㄗᕪࡀ⌮ㄽୖⓎ⏕ࡋ࡞࠸㸬ࡲࡓ㸪 ࡇࢀࡼࡾ㸰ḟ⤒㊰ࡢ᥎ᐃ⏝ࡍࡿ⿵ຓ㞧㡢ࡢ㟁ຊࢆపῶࡉࡏࡿࡇࡀྍ⬟
࡞ࡾ㸪ࢩࢫࢸ࣒యࡢᾘ㡢ᛶ⬟ࢆྥୖࡉࡏࡿ㸬ᮏ❶࡛ࡣᚑ᮶ᆺࡢPre-inverseᆺ ANC ࢩࢫࢸ࣒ࡋ࡚ SSCF 㐺ᛂࣝࢦࣜࢬ࣒ࡢㄝ᫂ࢆ⾜࠸㸪ḟᥦᡭἲࡢㄝ
᫂ࢆ⾜࠺㸬ࡲࡓ㸪ࢩ࣑࣮ࣗࣞࢩࣙࣥᐇ㦂࡚ᥦᡭἲࡢ᭷ຠᛶࢆ☜ㄆࡋ㸪ᐇᐇ 㦂࡛ᐇ⎔ቃୗ࡚ၥ㢟࡞ࡃືసࡍࡿࡇࢆ☜ㄆࡍࡿ㸬
3.2 SSCF ࢆ ࢆ⏝࠸ࡓ Pre-inverse ᆺ ANC ࢩࢫࢸ࣒
ᅗ 3. 1 Pre-inverse ᆺ ANCࡢᵓᡂࢆ♧ࡍ㸬ࡇࡇ࡛㸪HP(z)㸪HS(z)ࡣࡑࢀ
ࡒࢀ㸯ḟ⤒㊰㸰ḟ⤒㊰ࡢఏ㐩㛵ᩘࢆ⾲ࡋ࡚࠸ࡿ㸬ࡲࡓ㐺ᛂࣇࣝࢱHˆC(z)ࡣ )
(z H zM P
ࢆ᥎ᐃࡍࡿไᚚࣇࣝࢱ㸪HˆSc(z)ࡣ㸰ḟ⤒㊰HS(z)ࡢ㏫ఏ㐩㛵ᩘࢆ
᥎ᐃࡍࡿࡓࡵࡢ㐺ᛂࣇࣝࢱ࡛࠶ࡿ㸬ྛಙྕࢆ௨ୗ♧ࡍ㸬
) (n
g 㸸㦁㡢
) (n
p 㸸㸯ḟ⤒㊰㏻㐣ᚋࡢ㦁㡢 )
(n
y 㸸ほ ಙྕ
) (n
w 㸸⿵ຓ㞧㡢 )
(n
f 㸸ไᚚಙྕ
) (n
d 㸸㸰ḟ⤒㊰㏻㐣ᚋࡢไᚚಙྕ
࡞࠾㸪㦁㡢g(n)ཬࡧ㸪⿵ຓ㞧㡢w(n)ࡣ࠸⊂❧↓┦㛵࡞ಙྕ࡛࠶ࡿ㸬ࡲ
ࡓ㸪⿵ຓ㞧㡢w(n)ࡣᑐ㇟ࡍࡿ࿘Ἴᩘ㡿ᇦ࡛ⓑⰍࡢಙྕ࡛࠶ࡿ㸬ec(n)ࡣ㐺ᛂ
ࣇࣝࢱHˆSc(z)ࡢ㐺ᛂࣝࢦࣜࢬ࣒᭦᪂ࡢࡓࡵࡢㄗᕪಙྕ࡛࠶ࡿ㸬
ᅗ 3. 1 Pre-inverse ᆺANCࡢᵓᡂᅗ ( )
( )
NLMS
′ ( ) ′ ( )
( ) g( )
( ) ( )
( ) g′ ( ) ( ) ( )
NLMS ′( )
㞧㡢※
′ ( )
ཧ↷䝬䜲䜽 ㄗᕪ䝬䜲䜽
ḟ㡢※
ྛ㐺ᛂࣇࣝࢱࡘ࠸࡚㸪ไᚚࣇࣝࢱHˆC(z)ࡣ㸪
¦
NCi
i i C
C z h n z
H
0
, ( ) ) ˆ
ˆ ( 㸦 3.1 㸧
ࡇࡇ࡛㸪NCࡣHˆC(z)ࡢࢱࢵࣉᩘ㸪ˆ ( )
, n
hCi ࡣHˆC(z)ࡢi␒┠ࡢࢱࢵࣉಀᩘ࡛࠶ࡿ㸬
ࡲࡓ㸪㐺ᛂࣇࣝࢱHˆSc(z)ࡣ㸪
¦
c cc NS
i
i i S
S z h n z
H
0 ,( ) ) ˆ
ˆ ( 㸦 3.2 㸧
ࡼࡾ⾲ࡉࢀࡿ㸬ࡇࡇ࡛㸪NScࡣHˆSc(z)ࡢࢱࢵࣉᩘ㸪ˆ ( )
, n
hSci ࡣHˆSc(z)ࡢi␒┠ࡢࢱ
ࢵࣉಀᩘ࡛࠶ࡿ㸬ࡲࡓ㸪ࡍ࡚ࡢ㐺ᛂࣇࣝࢱ࠾࠸࡚NLMS (Normalized Least
Mean Square) ࣝࢦࣜࢬ࣒[18]ࢆ⏝࠸࡚࠾ࡾ㸪ྛࢱࢵࣉಀᩘࡢ᭦᪂ࡣ㸪
) ( ) (
) ( ) ) (
ˆ ( ) 1 ˆ (
n n
n n n y
n C C T
C g g
h g
h P 㸦 3.3 㸧
) ( ) (
) ( ) ) (
ˆ ( ) 1 ˆ (
n n
n n n e
n S S T
S y y
h y
hc c Pc c 㸦 3.4 㸧
࡞ࡿ㸬ࡇࡇ࡛㸪PCPScࡣࡑࢀࡒࢀࡢ㐺ᛂࣇࣝࢱࡢࢫࢸࢵࣉࢧࢬ㸪T ࡣ㌿
⨨ࢆ⾲ࡍ㸬ࡲࡓ㸪
T N C C
C
C(n) [hˆ (n),hˆ (n),...,hˆ C(n)]
ˆ ,0 ,1 ,
h 㸦 3.5 㸧
T
NC
M n g M
n g M n g
n) [ ( ), ( 1),..., ( )]
(
g 㸦 3.6 㸧
T N S S
S
S(n) [hˆ (n),hˆ (n),...,hˆ S(n)]
ˆc c,0 c,1 c, c
h 㸦 3.7 㸧
T
NS
n y n
y n y
n) [ ( ), ( 1),..., ( )]
( c
y 㸦 3.8 㸧
ᅗ 3. 2 HˆSc(z)᥎ᐃࡢಙྕࡢὶࢀ
ᅗ 3. 2㐺ᛂࣇࣝࢱHˆSc(z)᥎ᐃࡢಙྕࡢὶࢀࢆ♧ࡍ㸬HˆSc(z)ࡣ⿵ຓ㞧㡢 )
(n
w ࢆ⏝ࡋ㸪┤ิᆺࡢࢩࢫࢸ࣒ྠᐃࡋ࡚㸰ḟ⤒㊰ࡢ㏫ఏ㐩㛵ᩘzM HS(z)
ࢆ᥎ᐃࡍࡿ㸬᥎ᐃࡋࡓ⤖ᯝࡣไᚚࣇࣝࢱᚋẁࡢࣇࣝࢱHˆSc(z)ࢥࣆ࣮ࡍࡿ㸬 ࡇࢀࡼࡾ㸪㸰ḟ⤒㊰HS(z)ࡣ┦ẅࡉࢀ㸪
M S
S z H z z
Hˆc( ) ( ) 㸦 3.9 㸧
࡞ࡿ㸬㐺ᛂࣇࣝࢱHˆC(z)࡛ࡣzMHP(z)ࢆ᥎ᐃࡍࡿࡇ࡞ࡾ㸪㸯ḟ⤒㊰ࢆ
㏻㐣ࡋࡓ㦁㡢 p(n)㸰ḟ⤒㊰ࢆ㏻㐣ࡋࡓไᚚಙྕ d(n)ࡣᡴࡕᾘࡋ࠶࠺ࡇ࡞
ˆ zMH (z) NLMS
g
g
SSCF 㞧㡢※
ཧ↷䝬䜲䜽 ㄗᕪ䝬䜲䜽
ḟ㡢※