MainOfManuscript.dvi

Size: px

Start display at page:

Download "MainOfManuscript.dvi"

あやかりゅうとう
5 years ago
Views:

1 OFDM A Study on Transmission Characteristics of OFDM with Directional Antenna GD150

2 LAN OFDM OFDM OFDM 1 i

3 OFDM OFDM OFDM OFDM OFDM OFDM OFDM ii

4 42 44 iii

5 1 1.1 AV LAN 2.4GHz 5GHZ LAN 1.1 LAN 20Mbps 1.1: LAN 1

6 LAN 2.4GHz LAN IEEE802.11g 5GHz LAN IEEE802.11a OFDM(Orthogonal Frequency Division Multiplexing) [1] OFDM OFDM OFDM OFDM LAN 1.2 OFDM OFDM [2]-[5] 2

7 OFDM OFDM [6] FFT Pre-FFT FFT Post-FFT FFT FFT FFT FFT weight control (a) Pre-FFT type weight control (b) Post-FFT type 1.2: OFDM LAN 1.2(b) 3

8 1.3 RF [7][8]. 1.3 OFDM 1.3 RF RF BPF LPF A/D OFDM Receiver IEEE802.11a Direction controler 1.3: 1.2(a) 1.2(a) OFDM 4

9 2 OFDM 3 4 5

10 2 OFDM LAN Bluetooth 5.2GHz LAN LAN LAN [9][10] 2.1 (Ray) (Trace) 6

11 2 imaging method ray-launching method R R E = e jkr R (2.1)

12 Tx(1,1) Tx(0,1) Tx(1,1) Rx Tx(1,0) Tx Tx(1,0) Tx(1,1) Tx(0,1) Tx(1,1) Tx(n h,n v):image of Tx nh : number of reflections in horizontal plane nv : number of reflections in vertical plane 2.1: Fresnel TE (2.2),TM (2.3) Γ TE = cos θ i ɛ c sin 2 θ i (2.2) cos θ i + ɛ c sin 2 θ i Γ TM = ɛ c cos θ i ɛ c sin 2 θ i (2.3) ɛ c cos θ i + ɛ c sin 2 θ i θ i i ɛ c = ɛ r jδ/ωɛ 0 ( ɛ r σ µ r ) ɛ r =6.76 σ= µ r =1 x y z l m n i E i (2.4) E i = λ G t (i) G r (i)γ l+m+n (2.4) 4πd e jkd λ d c k δ Dirac G t,g r E i (2.5) 2 P r = E i (2.5) i 8

13 ( (2.6),(2.7)) ( (2.8)) D (θ) = cos Θ h (θ) ( θα θ θ α ) α F/B cos Θ h (θ < θ α,θ α <θ) log Θ h = 10 2 log 10 {cos (θ h /2)} (2.6) (2.7) D(θ) = (1 + cos(θ)) (2.8) D(θ) θ θ h α F/B FB [db] 0 0 [db] [deg.] 180 [deg.] (a) (d) 2.2: 9

14 : 2.1: Frequency 5.2GHz Tx antenna position [m] (1,1,1) Tx antenna pattern Omni-directional Rx antenna height [m] 1.0 Rx antenna pattern Omni-directional Cardiod pattern Reflection times 6 Room size [m] Polarization Vertical polarization Material of Walls/floor/ceiling Concrete OFDM GI:Guard Interval GI ISI Inter-Symbol Interference: OFDM 10

15 GI DUR GI 2.4 DUR 100dB IEEE802.11a OFDM GI 800ns m GI (800ns) GI Max delay time [ns] Length on a side [m] 2.4: (BER) f(t) P T d S P = i f(t i ) (2.9) T D = 1 P (t i t 0 )f(t i ) (2.10) i S = [ 1 P (ti t 0 ) 2 f(t i ) T 2 D ] 1 2 (2.11) 11

16 m 2.5(a) 2.5(b) (a) 22.7[ns] (b) 18.5[ns] 2.10 DUR DUR DUR OFDM 6 Distance y [m] Distance y [m] Distance x [m] (a) Omni-directional [ns] Distance x [m] (b) Cardioid pattern (every 90 degrees) 2.5: 12

17 OFDM 2.6 OFDM 2.6(a) U OFDM 2.6(b) CNR OFDM BER CNR CNR CNR N n N (C/N) min [db] =20log(P (T 0 ) P (T i )/n (2.12) i=1 CNR OFDM DUR CNR P(t) D U 1/(T -T ) 1 0 U1 U2 1/(T -T ) 2 0 T 0 T 1 T 2 (a) (b) 2.6: OFDM DUR [11] DUR 20MHz 50ns 50ns 13

18 0.5 x 5.5 y=5 x 0.5m DUR ,30,60,90,120 DUR DUR DUR [db] omni Rotates for every angle [deg] 2.7: DUR DUR CNR DUR 19.5dB 15 DUR 27dB DUR 14

19 2.2 OFDM OFDM OFDM OFDM [12][13] f 1,f 2,..., f N N N N x(t) = s n (t) =R[ e j2πfnt u n (t)] (2.13) n=1 n=1 u n (t) = k= a n,k g(t kt s ) a n,k (2.13) N u(t) = e j2πf N t u n (t) (2.14) n=1 f n = f n f c n f n f c OFDM 2.8 (I,Q) T S RF 15

20 cos2 f t c mapping data S/P mapping IDFT P/S GI addition s(t) mapping cos2 f t c (a) OFDM Transmitter -sin2 f t c LPF demap r(t) GI removal S/P DFT demap P/S data LPF demap -sin2 f t c (b) OFDM Receiver 2.8: OFDM 1/T n c n n T x(t) x(t) = n= c n e j 2πnt T (2.15) (2.14) (2.15) c n n n f n = n/t N =2L +1 OFDM s(t) = L k= n= L a n,k e j 2πn(t kts) T g(t kt s ) (2.16) 16

21 a n,k n k 1 ( G t T ) g(t) = 0 (t<0,t>t) (2.17) OFDM 2.9(a) 2.9(b) GI Ts T GI data (a) OFDM symbol T window window (b) GI eliminates ISI 2.9: h(t) s R (t) s R (t) = h(u)s(t u)du + n c (t) (2.18) (2.18) 1 OFDM 2 OFDM 17

22 OFDM h(u)s(t u)du = R[ = R[ h(u) m= N 1 { e j2πnf(t mt ) m= n=0 N 1 g(t u mt ) d(m, n)e j2πnf(t u mt ) e j2πfc(t u) du] n=0 } h(u)g(t u mt )e j2π(fc+nf)u du d(m, n)e j2πfct ](2.19) (2.19) s B (t) s B (t) N 1 { e j2πnf(t mt ) m= n=0 } h(u)g(t u mt )e j2π(fc+nf)u du d(m, n)(2.20) s B (t) t = kt +it s (i =0, 1, 2,,,N 1) s B (k, i) s B (k, i) = N 1 m= n=0 [ e j2πnf{(k m)t +its} ] h(u)g {(k m)t + it s u} e j2π(fc+nf)u du d(m, n) (2.21) N DFT k OFDM l x(k, l) x(k, l) = 1 N = N 1 i=0 N 1 m= n=0 2πil j s B (k, i)e N e j2πnf(k m)t Ĥ(k, m, l, n)d(m, n) (2.22) Ĥ(k, m, l, n) = 1 N N 1 i=0 e j 2π(n l)i N h(u)g {(k m)t + it s u} e j2π(fc+nf)u du(2.23) (2.22) x(k, l) x(k, l) =Ĥ(k, k, l, l)d(k, l)+ N 1 m= n=0 e j2πnf(k m)t Ĥ(k, m, l, n)d(m, n) (2.24) 18

23 (2.24) 1 2 OFDM Ĥ(k, m, l, n) = 1 N N 1 i=0 e j 2π(n l)i N (k m)t +its+t g (k m)t +it s 1 f h(u)e 2pi(fc+nf)u du (2.25) h(t) t =0 t = T g (k m)t +its+t g (k m)t +it s 1 f Tg h(u)e 2pi(fc+nf)u 0 h(u)e j2π(fc+nf)u du (m = k) du = 0 (m k) H(f) H(f) = Tg 0 (2.26) h(t)e j2πft dt (2.27) m = k Ĥ(k, m, l, n) = { 1 N = N 1 i=0 e j 2π(n l)i N H(f c + nf) (n = l) 0 (n l) H(f c + nf) H(f c + nf) (m = k, n = l) Ĥ(k, m, l, n) = 0 ( ) } (2.28) (2.29) (2.24) x(k, l) =H(f c + lf)d(k, l) (2.30) l (f c + nf) 19

24 2.2.2 OFDM OFDM 2.10 OFDM 5GHz LAN H(f) OFDM [15] Tx data source Encorder/ Interleaver Modulation IFFT Multipath Channel H(f) Gausian Noise Rx data Deinterleaver/ Viterbi decoder Demodulation FFT Syncronizatio/ Channel estimation 2.10: OFDM

25 Received power [db] Delay time [ns] : -60 Spectrum [db] Frequency [MHz] 2.12:

26 2.2: OFDM Carriers 48(data symbol) 4(pilot symbol) FFT points 64 Carrier spacing 312.5kHz Symbol duration 3.2µs Modulation QPSK,16QAM Channel code/decode Convolutional coding(r=3/4) /Viterbi decoding Channel Transfer function presumed by Raytracing OFDM , 2.15 E b /N 0 BER QPSK 16QAM BER BER 30 BER=10 4 QPSK 6.5dB 16QAM 5dB Magnitude [db] Magnitude [db] Frequency [MHz] (a) Frequency [MHz] (d) 2.13: 22

27 10-1 Bit Error Rate Eb/No [db] 2.14: BER QPSK 10-1 Bit Error Rate Eb/No [db] 2.15: BER 16QAM 23

28 2.2.4 OFDM BER 2 BER Bit Error Rate QPSK 16QAM Angle [deg] 10-1 Bit Error Rate QPSK 16QAM Angle [deg] : BER

29 2.16 BER BER BER BER (1,1,1) 1 DUR QAM BER= ,90 25

30 100 Cumulative distribution [%] deg 30 deg 45 deg 60 deg 90 deg BER : BER Cumulative distribution [%] deg 30 deg 45 deg 60 deg 90 deg BER 2.18: BER ( DUR ) 26

31 diversity [16] OFDM 27

32 BER 4 λ/4 λ/2 λ 4 1 λ/2 2 1 BER 3.1: directive control select pattern omni-directional cardioid (every 30 step) selective diversity number of element element-spacing 4 element λ/4 λ/2 λ 2 element λ/2 1 element reception ,5, m 1m 3.2: ɛ r σ steel glass wood

10 m measurement area 6 m : Tx height : 2m material : steel height : 1.5m material : steel height : 0.7m material : wood 3.1: 3.1.3 1 BER 3.

33 10 m measurement area 6 m : Tx height : 2m material : steel height : 1.5m material : steel height : 0.7m material : wood 3.1: BER 3.2(a) BER 3.2(b) LOS line-of-site NLOS non-line-of-site BER LOS LOS NLOS NLOS 1e -5 1e -2 1e -5 1e -2 (a) (d) 3.2: BER 29

34 BER λ/2 4 1λ BER= % 2 10% 4 λ 30% λ/2 20% λ/4 14% 100 Cumulative distribution [%] cardioid pattern 4div div. /2 4div. /2 omnidirectional 4div. / BER 3.3: BER λ/8 λ BER BER BER λ/4 5λ/8 30

35 10-1 diversity cardioid ( /4) Average BER /8 2/8 3/8 4/8 5/8 6/8 7/8 8/8 Element spacing [ ] 3.4: 31

36 OFDM OFDM : Tx antenna sleeve antenna Radiation pattern omni-directional(zx-plane) Tx signal IEEE802.11a Frequency 5.17GHz Bandwidth 20MHz Modulatin 16QAM Coding Convolutional coding Encoding rate 1/2 Interleave size 1 OFDM symbol 3.4: 4 element rectangular array Element-spacing λ/4 Radiation pattern cardioid pattern (every 30 step) omni-directional 4 element selective diversity Element-spacing λ/4,λ/2 32

37 3.5: OFDM Tx Fofmat Coding Puncturing /Interleaver Mapping IFFT Guard Interval Insertion Digital I/Q modulator DAC Upconverter and PA 3.6: (a) 4 (b) 4 3.7: 33

38 dB 1 5dB S GHz 1dB 4 1 2dB dB 0 0 [db] [deg.] Omni by 4 element Omni by 1 element Cardioid by 4 element 3.8: 34

1 3 2 0 3.9: -1 Amplitude [db] -2-3 -4-5 25 4.75 5

39 : -1 Amplitude [db] Frequency [GHz] (a) s21 Amplitude [db] Frequency [GHz] (d) 3.10: 35

40 3.11 6m 9m 110cm y [m] 5... Tx. Position (110cm) 110cm x [m] 3.11: x=6 y 1λ 10 BER 3.13 BER BER Amplitude [db] Amplitude [db] Frequency [GHz] (a) Frequency [GHz] (d) 3.12: 36

41 BER cardioid 1 element Received point 10 (a) LOS BER BER Received point (d) NLOS BER cardioid 1 element 3.13: 37

42 1m BER Cumulative distribution [%] cardioid 4div ( /2) 20 4div ( /4) 2div ( /2) BER 3.14: % λ/4 λ/ dB F/B

43 100 Distribution [%] BER cardioid 4div. /2 4div. /4 2div. /2 1 element 3.15: % 39

44 4 5GHz OFDM 4 5GHz GI 30 5λ/8 λ/4 OFDM λ/2 40

45 SHARP D3 D2 41

46 [1] Yi Sun, Bandwidth-Efficient Wireless OFDM, IEEE Journal on selected areas in communications, Vol.19, No.11, pp , Nov [2] M.Ise Y.Matsumoto M.Umehira OFDM, DSP98-151,SAT98-71,RCS98-172,Jan [3], RCS pp Jul [4] OFDM, pp [5] OFDM, Oct [6] OFDM RLS, DSP WBS Jul.2003 [7] H.Aoyama,H.Arai, Mutual Coupling Matrix Estimation and Null Forming Methods for MBF Antenna, ISAP 04 3A2-3,JAPAN Aug [8] 4 5GHz OFDM,B Mar [9], A P94-35, Aug [10],,, B Vol., J85-B, No.2 pp , Feb

47 [11], 5GHz OFDM,, A P , SANE , RCS , Oct [12] P.H.Moose, A Technique for Orthogonal Frequency Division Multiplexing Frequency Offset Correction, IEEE Trans. Comm., 42,30,pp [13] IEEEP802.11a. High Speed Physical Layer(PHY) in 5GHz band, [14],, OFDM MATLAB,, [15] H.Iwai and Y.Karasawa, Wideband Propagation Model for the Analysis of the Effect of the Multipath Fading of the Near-Far Problem in CDMA Mobile Radio System, IEICE Trans. Commun., vol.e76-b, No.2 Feb [16],

48 [1] OFDM B [2] OFDM B [3] Yosuke Nakatsuka, Fumiyo Sato and Hiroyuki Arai, Reception Characteristics of OFDM under Multipath Channel with Directional Antenna, 2004 Asia-Pacific Microwave Conference,New Delhi, India, Dec

A Study of Adaptive Array Implimentation for mobile comunication in cellular system GD133

A Study of Adaptive Array Implimentation for mobile comunication in cellular system 15 1 31 01GD133 LSI DSP CMA 10km/s i 1 1 2 LS-CMA 5 2.1 CMA... 5 2.1.1... 5 2.1.2... 7 2.1.3... 10 2.2 LS-CMA... 13 2.2.1...