NAIST-IS-MT0751044 2.4GHz W-LAN 2008 8 20
( ) ( ) ( ) ( ) ( )
2.4GHz W-LAN ISM(Industrial, Sientific and Medical) 2.4GHz IEEE802.11b/gW-LAN 2.4GHz W-LAN 2.4GHz ISM (Industry Scientific and Medical) ISM W-LAN ISM ISM IEEE802.11g W-LAN OFDM W-LAN W-LAN BER 19.7, PER 40.5, NAIST-IS- MT0751044, 2008 8 20. i
IEEE802.11b/g, ISM,, OFDM ii
Reduction of Microwave Oven Interference for 2.4GHz band W-LAN Hiromi Takahata Abstract This paper proposes a microwave oven interference canceller for IEEE 802.11g (Wireless Local Area Network) at 2.4GHz band. Since microwave oven and W- LAN standardized by IEEE 802.11b/g use the same 2.4 GHz band, which is known as an ISM (Industrial, Scientific and Medical) band, interference from microwave oven could degrade the performance of the W-LAN. The proposed interference canceller is based on an adaptive comb filter in order to reduce the narrow-band interference. Computer simulation result shows that the proposed canceller is capable of reducing the interference. Keywords: IEEE802.11b/g, ISM device, Microwave Oven Interference, OFDM Master s Thesis, Department of Information Systems, Graduate School of Information Science, Nara Institute of Science and Technology, NAIST-IS-MT0751044, August 20, 2008. iii
1 1 1.1............................... 1 1.2................................. 3 1.3................................. 5 1.4............................... 6 2 7 2.1. ISM W-LAN.......................... 7 2.2............................. 8 2.3..................... 9 2.4.............................. 9 2.5............................ 28 3 32 3.1....................... 32 3.2........................ 32 3.3.............................. 34 3.4.............................. 34 3.5.............................. 36 3.6. LAN............ 37 3.7.................. 38 3.7.1........................ 38 4 W-LAN 41 4.1. LAN...... 41 iv
4.1.1 OFDM(Orthognal Frequency Division Multiplex: )................. 41 4.1.2 OFDM....... 42 4.2............................ 42 5 50 52 55 v
2.1........................... 9 2.2 ( ) 11 2.3 ( 2.447GHz)............................... 12 2.4 ( 2.447GHz). 13 2.5 ( )... 15 2.6 ( )...... 15 2.7.............. 16 2.8 ( 0.5ms)............ 16 2.9 ( 70ms)............ 17 2.10 ( 0.5ms)............ 17 2.11 ( ) Vector Signal Analyzer(VSA)................. 19 2.12 ( ) Vector Signal Analyzer(VSA)................. 20 2.13 ( ) Vector Signal Analyzer(VSA)...... 21 2.14 ( ) Vector Signal Analyzer(VSA).................. 22 2.15 ( ) Vector Signal Analyzer(VSA).................. 23 2.16 ( 2.412GHz Vector Signal Analyzer )................ 24 vi
2.17 ( 2.447GHz Vector Signal Analyzer )................ 25 2.18 ( 2.467GHz Vector Signal Analyzer )...................... 26 2.19 ( 2.412GHz Vector Signal Analyzer )...................... 27 2.20......... 29 2.21............ 30 2.22......... 31 3.1........................... 32 3.2 0.9 (, 2.447GHz).. 35 3.3 0.8 (, 2.447GHz).. 35 3.4 0.7 (, 2.447GHz).. 36 3.5 0.8 16.64ms (, 2.447GHz)............................... 37 3.6 ( 16 )........................... 39 3.7 W-LAN................. 40 4.1 W-LAN 2.447GHz............................... 43 4.2 W-LAN 2.457GHz............................... 44 4.3 W-LAN 2.447GHz 44 4.4 W-LAN 2.457GHz 45 4.5 W-LAN 2.472GHz 45 4.6 W-LAN 2.412GHz 46 4.7 W-LAN 2.442GHz 46 4.8 W-LAN 2.442GHz 47 vii
4.9 W-LAN 2.462GHz 47 4.10 W-LAN 2.472GHz 48 viii
2.1................................ 10 4.1 OFDM Parameters.......................... 48 4.2 ( 2.457GHz)... 49 ix
1 1.1.,, W-LAN W-LAN,,,,,,, W-LAN,,,, W-LAN. W-LAN, 8,811, [1],,,, 1
CPU,,,,,,, Web,,,, ADSL (Asynchronous Digital Subscriber Lines),, IEEE 802.11b/g/n 1 W-LAN, PC W-LAN,, PDA (Personal Digital Assistance) W-LAN.,,,,, W-LAN 1 IEEE 802.11, IEEE - (The Institute of Electrical and Electronic Engineers) LAN 802 1998 7 W-LAN 2
(http://biz.natioanl.jp/ebox/kahs/index.html), W-LAN,,, IEEE 802.11b/gW-LAN, 2.4GHz,, ISM(Industrial, Scientific and Medical), ISM, 2.4GHz [2], W-LAN 1.2., W-LAN [2],,,, 2,. [2],, [2] 1994, PHS 1.9GHz, 2.4GHz ISM [3],,,,,,,, 3
, IEEE802.11b/g W-LAN [4], 1.9GHz, 2.5GHz, 1.9GHz, 2.5GHz, QPSK( : Quandrature Phase Shift Keying) DS-SS( : Direct Sequence Spread Spectrum), TDMA( : Time Division Multiple Access),,,,, IEEE802.11g W-LAN OFDM( : Orthogonal Frecency Division Multiplexing), [5], IEEE802.11b IEEE802.11b DS-SS( ), OFDM [6], DS-SS,, BER,,,,, 4
,, [7] DS-SS, [8] DS-SS [9],,, OFDM W-LAN PC,, IEEE802.11a OFDM W-LAN OFDM, OFDM 1.3., OFDM IEEE 802.11g W-LAN,, W-LAN, IEEE802.11g W-LAN OFDM,,, IEEE802.11g,,,,,,, 5
OFDM, OFDM, IEEE 802.11g,, 4,, W-LAN,, 1.4., 2, 3,,, 4, OFDM W-LAN,, 5 6
2 2.1. ISM W-LAN ISM(Industry Scientific and Medical) 1. 2.4 2.5GHz 5.725 5.875GHz 2 ISM. ISM,,,,, ISM 10MHz 2001 2.4GHz 2.4GHz. 2.4GHz Bluetooth W-LAN ISM W-LAN, 5.725 5.875GHz ETC(Electronic Toll Collection System) ISM 1 ITU : International Telecommunication Union. 7
W-LAN ISM 2.2.,, 1962 500W 600W,, ISM 2.4GHz 50MHz., ISM,,. 50Hz 60Hz, 4kv. 1,.,., 30 50kHz,,.,,. 50Hz 60Hz. [10]., 3 (,, ), ( )1,. 8
2.3.,, 2.1. 2.1., Agilent Technologies 89600S Vector Signal Analyzer 2.4GHz W-LAN 1/2, ( ). 2.1 2.4. W-LAN 2.4GHz,., 15cm 2.2 110dB.. 60dB.. 9
2.1 1/2 2.447GHz, 2.467GHz 38.4MHz 200ms 150cc 60Hz Agilent Technologies 89600S Vector Signal Analyzer 95 NE-C2 2004 RE-S160W 98 ER- FX1(H) 15cm, 1m, 3m, 2.3 15cm 93dB, 1m 103dB. 3m 105dB, 15cm 1/10, 1m.,,,,,,., 15cm 10
-50-60 on off -70 Interference(dB) -80-90 -100-110 -120 0 0.01 0.02 0.03 0.04 0.05 Time(s) 2.2 ( ), 3 2.4. 55dB,,,,, 11
-90-95 15cm 1m 3m Interference(dB) -100-105 -110-115 0.2 0.205 0.21 0.215 0.22 0.225 0.23 0.235 0.24 0.245 0.25 Time(s) 2.3 ( 2.447GHz) 12
-50-60 atatame toaster oven -70 Interference(dB) -80-90 -100-110 -120 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 Time(s) 2.4 ( 2.447GHz) 13
, ISM 13 (2.412GHz 2.484GHz), 2.5, 2.6., sh2412 2.412GHz..,,,,,.,. 2.5 2.447GHz 2.457GHz. 2.452GHz,, 2.457GHz. 2.472GHz 2.452GHz. 2. 2.14.. 2.7, 1/60Hz, 1/50Hz., 2,. 1/120Hz,. 2.9. 2.10., 22KHz.. 14
-50-60 sh2412 sh2442 sh2452 sh2457-70 Interference(dB) -80-90 -100-110 -120 0.1 0.105 0.11 0.115 0.12 0.125 0.13 0.135 0.14 0.145 0.15 Time(s) 2.5 ( ) -50-60 -70 to2412 to2442 to2452 to2457 to2472 Interference(dB) -80-90 -100-110 -120 0.1 0.105 0.11 0.115 0.12 0.125 0.13 0.135 0.14 0.145 0.15 Time(s) 2.6 ( ) 15
10-5 "s2.447-sh-1.txt" "s2.447-to-1.txt" 10-6 10-7 Interference(w) 10-8 10-9 10-10 10-11 10-12 0.06 0.07 0.08 0.09 0.1 0.11 0.12 0.13 0.14 Time(s) 2.7 2.8 ( 0.5ms) 16
2.9 ( 70ms) 2.10 ( 0.5ms) 17
Vector Signal Analyzer, Vector Signal Analyzer(VSA). 2.11.,, (dbm),.,,,, 0.8ms, 40ms 40ms,,,.., VSA 2.12..,,.,.,. 2.14, 2.15.,, 2 2.18., 2.19. VSA 2.17.. 18
2.11 ( ) Vector Signal Analyzer(VSA) 19
2.12 ( ) Vector Signal Analyzer(VSA) 20
2.13 ( ) Vector Signal Analyzer(VSA) 21
2.14 ( ) Vector Signal Analyzer(VSA) 22
2.15 ( ) Vector Signal Analyzer(VSA).,.,. VSA 2.17sim 2.19..,, 3m,,,,, 23
2.16 ( 2.412GHz Vector Signal Analyzer ) 24
2.17 ( 2.447GHz Vector Signal Analyzer ),,,,,,,,. 2.7, 16ms, 20ms, 8ms., 40dBm 110dBm,,. 25
2.18 ( 2.467GHz Vector Signal Analyzer ) 26
2.19 ( 2.412GHz Vector Signal Analyzer ) 27
2.5.,,. k X k = I k + jq k (2.1). I k, Q k,. m R(m; k) = E[X k+m Xk] (2.2), k., T p = 1/f p (= 1/60 16.7ms). f s = 38.4MHz, D = T p /(1/f s ) = 640, 000. R(k) = R(D; k). r k 2.20 2.21. r k..,, 0, I k I k+d. 2.22.,, 28
2.20 29
2.21.,,.,,. 30
2.22 31
3 3.1.,,,.,,. 3.2., 3.1. r k. f s. 3.1 T D = D/f s d k = r k D,. 32
d k h k r k e k = r k h k d k. J k. J k = = 1 1 α 1 1 α e k l 2 α l (3.1) l=0 r k h k d k l 2 α l (3.2) l=0 α. J k h k. δj k /δh k = 0 (3.3) 0 = α l (r k l h k d k l )d k l (3.4) l=0 h k, h k = l=0 αl r k l d k l l=0 αl d k l 2 = N k D k., N k = D k = α l r k l d k l (3.5) l=0 α l d k l 2 (3.6) l=0 N k D k, h k. N k = r k d k + αn k 1 (3.7) 33
D k = d k 2 +αd k 1 (3.8) h k = N k D k (3.9) 3.3. 3 17.16ms( 66 ) 16.64ms(64 ) 16.12ms(62 ) 3.2, 3.7, 3.4. 17.16ms 16.12ms 16.64ms(64 ) 3.4. 0.9 0.8, 0.7 3 0.9 0.8 0.7 0.8 0.8. 34
-50-60 normal simple-add alpha09-multi -70 Interference(dB) -80-90 -100-110 -120 0 0.02 0.04 0.06 0.08 0.1 Time(s) 3.2 0.9 (, 2.447GHz) -50-60 normal simple-add alpha08-multi -70 Interference(dB) -80-90 -100-110 -120 0 0.02 0.04 0.06 0.08 0.1 Time(s) 3.3 0.8 (, 2.447GHz) 35
-50-60 normal simple-add alpha07-multi -70 Interference(dB) -80-90 -100-110 -120 0 0.02 0.04 0.06 0.08 0.1 Time(s) 3.4 0.7 (, 2.447GHz) 3.5., 16.64ms 0.8. 3.7. normal. simple-add. alpha-multi,, (h),. 1, 3.7 simple-add.,., 0.8 16.64ms,. 15dB.,. 36
-50-60 normal simple-add alpha08-multi -70 Interference(dB) -80-90 -100-110 -120 0.05 0.06 0.07 0.08 0.09 0.1 0.11 0.12 0.13 0.14 0.15 Time(s) 3.5 0.8 16.64ms (, 2.447GHz) 3.6. LAN LAN, D,, 2,, 1,. 3.6 LAN. LAN s k, cs k. c,., m k. r k = cs k + m k (3.10). r k LAN ĉŝ k 37
ˆm k = r k ĉŝ k (3.11).,W-LAN, ˆm k m k. ˆm k D d k = ˆm k D. (3.7) (3.8), h k, e k = r k h k d k. e k e k = cs k. e k LAN, LAN ŝ k. e k ŝ k. ĉ = E[e k /Ŝk] 1 N N 1 l=0 e k s k (3.12) ĉ ŝ k. 3.7.,. IEEE802.11g, OFDM. OFDM (4 1.1. ) 0.8µs, 30 (0.78µs ), 16 3.6.,. 3.7.1, 110dBw ( 80dBm).,.,, 38
10-5 w/o cansel w cansel(16p) 10-6 10-7 Interference(w) 10-8 10-9 10-10 10-11 10-12 0.06 0.065 0.07 0.075 0.08 0.085 Time(s) 3.6 ( 16 ). W-LAN. 39
3.7 W-LAN 40
4 W-LAN 4.1. LAN,., LAN +. OFDM LAN 4.1.1 OFDM(Orthognal Frequency Division Multiplex: ) OFDM OFDM (ISI:Inter Symbol Interference) OFDM OFDM 41
IEEE802.11a IEEE802.11g 0.8µs 0.8µs 4.1.2 OFDM OFDM 6Mbps, 52( =4), BPSK,. 4.1. W-LAN. s c m, ŝ c + m. c, ŝ + c, ŝ c + m ŝ + c m. m., W-LAN, 2. 4.2. W-LAN, 16, 0.9 C/I(dB) 30dB 10dB. C/I(dB) 20dB BER 0.23 0.353 ( PER) 0.516 42
4.1 W-LAN 2.447GHz 0.111 C/I(dB) 0db 30dB BER C/I(dB) 10dB BER, PER 0.197 0.405,.,. 43
4.2 W-LAN 2.457GHz 4.3 W-LAN 2.447GHz 44
4.4 W-LAN 2.457GHz 4.5 W-LAN 2.472GHz 45
4.6 W-LAN 2.412GHz 4.7 W-LAN 2.442GHz 46
4.8 W-LAN 2.442GHz 4.9 W-LAN 2.462GHz 47
4.10 W-LAN 2.472GHz 4.1 OFDM Parameters 6Mbps 52 :4 BPSK R=1/2 IEEE802.11g OFDM 4.0µs 0.8µs 38.4MHz 48
4.2 ( 2.457GHz) C/I(dB) BER BER PER PER BER PER (with) (without) (with) (without) -50 0.499 0.498 0.100 0.100 0.000 0.000-40 0.186 0.276 0.837 0.597 0.900-0.240-30 0.680 0.261 0.202 0.554 0.193 0.352-20 0.350 0.232 0.111 0.516 0.197 0.405-10 0.240 0.189 0.730 0.472 0.165 0.399 0 0.070 0.109 0.740 0.411 0.102 0.337 10 0.310 0.220 0.350 0.353-0.090 0.030 20 0.003 0.000 0.032 0.000 0.000-0.320 with:with cansel, without:without cancel 49
5 W-LAN,.,,,.,.,,.,.,,.,,., IEEE802.11b W-LAN,. OFDM PER, 0.554 0.352 BER 0.351 0.232, W-LAN., PER 0.418 0.274, BER 0.179 0.067., PER 0.432 0.131, BER 0.189 0.051 50
., PER, BER 0.261 0.195.,. 3,,.,,., IEEE802.11b,. 51
,.. 52
.,.,..,,,.,,. 53
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