(LNA) (LNA) (PA)
ASK FSK PSK BER Bit Error Rate/ratio QPSK GMSK QAM OFDM
ASK FSK PSK ASK(Amplitude-shift keying) e( t) = S( t)cos( ω t + θ ) c AM S(t) [+1,0] [+1/2, 1/2] 1 1 2 S(t) 0 1 2 e(t) C O B A E = S( t) e j( ω ct +θ )
ASK FSK PSK FSK(Frequency-shift keying) m = 2ω d e( t) = cos( ω c t + θ + m S( t) dt) S(t) [+1/2, 1/2] e( t) e( t) (( ω c + ω d ) + θ ) (( ω ω + θ ) = cos t = cos t c d ) 1 2 S(t) 1 2 ω c ω d ω c ω d e(t) T b T b ω d T b = nπ T b = 1/ f b
ASK FSK PSK FSK e( t) = cos( ( ω c + ω d ) t + θ ) e ( t) = cos( ( ω ω t + θ ) e( t) = cosω t cos( ω t + θ ) sinω t sin( ω t + θ ) d c e( t) = cosω t cos( ω t + θ ) + sinω t sin( ω t + θ ) e( t) = e( t) = d c [ ] j( ωct+ θ ) j( ω ct+ θ ) ω t e + j sinω t e Re cos d [ ] j( ωct+ θ ) j( ω ct+ θ ) ω t e j sinω t e Re cos c d ) d d d d d c c ω t Q T b T b V = I + jq t I FSK I-Q
ASK FSK PSK PSK Phase-shift keying e( t) = cos( ω ct + φk ) E = e jφ k jωct e BPSK QPSK [ φ 0, φ1] = [ π,0] [ φ, φ01, φ00, φ10 ] = [ π / 4,3π / 4, 3π / 4, 11 π / 4] S(t) [0] [1] e(t) BPSK BPSK ASK
ASK FSK PSK QPSK(Quadri-PSK) [ φ, φ01, φ00, φ10 ] = [ π / 4,3π / 4, 3π / 4, 11 π / 4] [0,1] ( Q ) [1,1] ( I ) QPSK E = e jφ k jωct e [0,0] [1,0] [b]=[1,1,1,0,0,1,1,1,0,0,...] QPSK I(t) b 1 b 3 b 7 b 5 b 9 Q(t) T b f b = 1/T b T s b 2 (= 2T b ) b 4 T s b 6 b 8 b 10 T s =2T b f s = 1/T s [1, 1] [1, 0] [0, 1] [1, 1] [0, 0]
ASK FSK PSK QPSK [0,1] ( Q ) [1,1] ( I ) QPSK [0,0] [1,0] Offset-QPSK [b]=[1,1,1,0,0,1,1,1,0,0,...] I(t) T s b 1 b 3 b 7 b 5 b 9 Q(t) T s /2 b 2 b 4 b 6 b 8 b 10 [1,1] [1,1] [1,0] [0,0] [0,1] [1,1] [1,1] [0,1] [0,0]
ASK FSK PSK QPSK /4 QPSK [1, 1] [1, 1] [1, 0] [0, 1] [0, 0]
BPSK e( t) = d( t)cos( ω t + θ ) c d(t) BPSK e(t) jωt = d( t) cos( ω t + e dt c θ E( ω ) ) D(ω ω c ) D(ω) D(ω ω c ) ω c 0 d(t) ω c BPSK D(ω) d(t) BPSK
p(t) T 0 = 1 2f0 1 0 0 2T 2T 3T 4T 0 3T 0 0 T T 0 0 4T 0 0 0 f 0 f t BPSK 1 0 1 1
BPSK B( ω) = sin( ωt / 2) b A / 2 ωtb 2 f c f b f b f 0 f c f 0 f b f 0 BPSK f b f b 1 bit/s/hz QPSK BPSK 2 bit/s/hz
BPSK p es p(w) p em [0] A 0 A [1] β 0 β P em = p es = 1 erfc 2 A 2σ = 1 erfc 2 C N = 1 erfc 2 E N b o σ C = E b f b N = N B E b o 1bit N o 1Hz B
n-psk P n = PSK erfc C N π sin n QPSK P QPSK = erfc C / 2 N 10 1 10 2 10 3 8-PSK 16-PSK n-psk C/N E b /N o Eb fb C / N = = N B o n E N b o log 2 n 10 4 10 5 10 6 10 7 10 8 10 9 2-PSK 4-PSK 16-QAM C/N 10 10 0 5 10 15 20 25 C/N [db]
BER QPSK QPSK A B C = = o b QPSK N E N C BER erfc 2 1 2 / erfc 2 1 BER 1/2 [1,1] [1,0] [0,0] [0,1] A B C D [1,1] [1,0] [0,0] [0,1] A B C D
QPSK [0,1] ( Q ) [1,1] I(t) LPF π/2 [0,0] ( I ) [1,0] Q(t) LPF 2 DBM 0 o t π/2 /2 + Lo+ Lo +
QPSK cosω c t LPF cosω o t VCO π/2 LPF cos ωt sin2 ωt LPF sin ωt I(t) Q(t) sin Acos B = cos Acos B = 1 [sin( A + B) + sin( A B)] 2 1 [cos( A + B) + cos( A B)] 2 ω = ω c ω o d/dt NRZ 2 f clock x2 LPF VCO f clock
GMSK MSK 1 0 1 1 NRZ T b MSK LPF VCO e(t) f c f b /4 GMSK MSK(GMSK) (( ω c + ωd ) + θ ) (( ω ω + θ ) e( t) = cos t e( t) = cos c d ) t f d = f b 4 = 1 4T b MSK /2 FSK n GMSK π 1 0 MSK(GMSK) 0 [1,0,1,1,0,0,0...] π/2 π/2 π 1 0 1 2T b 4T 6T b b 0 8T b 0 t
GMSK MSK I(t) Q(t) π/2 1 0 1 1 0 0 0 T b 2T b I(t) π/2 Q(t) MSK MSK(GMSK π 0 t Q(t) MSK QPSK f b /2 π/2 t I(t) [1,0,1,1,0,0,0]
QAM 16QAM Q 00 10 10 00 01 11 4 [a 1,a 2,a 3,a 4 ] ABCD[a 1,a 2 ] [a 3,a 4 ] 01 01 00 11 11 00 10 10 11 01 11 01 10 00 I I- [a 1,a 3 ] a 1 a 3 S I I(t) LPF π/2 a 2 Q(t) Q- [a 2,a 4 ] LPF a 4 S Q
OFDM ( 16QAM) n QAM TV 1kHz WLAN 312.5kHz WLAN n = 64 n = 52 n = 48
OFDM 00 01 10 Q 10 11 00 f n f 1 IFFT t 1 t n DA DA LPF LPF I(t) Q(t) OFDM π/2 RF 01 01 11 11 11 01 I 11 01 00 10 00 10 10 00 1.5+j0.5 0.5+j0.5 1.5 j0.5 0.5 j1.5 A = I+jQ f 1 f f n IFFT A φ B s / 2 B s / 2 t 1 t 2 t I+jQ n f =312.5kHz n =52 3.2µsec n =64 n =48
Data Mapping Q I LPF LPF π/2 DS I(t) +1 P(t) P (t) 1 DS S(t) +1 1 +1 1 +1 D(t) 1