50 likes | 163 Views
Standard. Type. Year of Introduction. Multiple Access. Frequency Band. Modulation. Channel Bandwidth. ETACS. Cellular. 1985. FDMA. 900 MHz. FM. 25 kHz. NMT-450. Cellular. 1981. FDMA. 450-470 MHz. FM. 25 kHz. NMT-900. Cellular. 1986. FDMA. 890-960 MHz.
E N D
Standard Type Year of Introduction Multiple Access Frequency Band Modulation Channel Bandwidth ETACS Cellular 1985 FDMA 900 MHz FM 25 kHz NMT-450 Cellular 1981 FDMA 450-470 MHz FM 25 kHz NMT-900 Cellular 1986 FDMA 890-960 MHz FM 12.5kHz GSM Cellular/ PCS 1990 TDMA 890-960 MHz GMSK 200 kHz C-450 Cellular 1985 FDMA 450-465 MHz FM 20 kHz/ 10 kHz ERMES Paging 1993 FDMA Several 4-FSK 25 kHz CT2 Cordless 1989 FDMA 864-868 MHz GFSK 100 kHz DECT Cordless 1993 TDMA 1880-1900 MHz GFSK 1.728 MHz DCS-1800 Cordless/ PCS 1993 TDMA 1710-1880 MHz GMSK 200 kHz Major Mobile Radio Standards in Europe
Standard Type Year Of Introduction Multiple Access Frequency Band Modulation Channel Bandwidth AMPS Cellular 1983 FDMA 824-894 MHz FM 30 kHz NAMPS Cellular 1992 FDMA 824-894 MHz FM 10 kHz USDC Cellular 1991 TDMA 824-894 MHz p/4- DQPSK 30 kHz CDPD Cellular 1993 FH/ Packet 824-894 MHz GMSK 30 kHz IS-95 Cellular 1993 CDMA 824-894 MHz 1.8-2.0 GHz QPSK/ BPSK 1.25 MHz GSC paging 1970 Simplex Several FSK 12.5 kHZ POCSAG Paging 1970 Simplex Several FSK 12.5 kHZ FLEX Paging 1993 Simplex Several 4-FSK 15 kHz DSC-1900 (GSM) PCS 1994 TDMA 1.85-1.99 GHz p /4- DQPSK 200 kHz PACS Cordless 1994 TDMA/ FDMA 1.85-1.99 GHz p /4- DQPSK 300 kHz MIRS SMR/ PCS 1994 TDMA Several 16-QAM 25 kHz iDEN SMR/ PCS 1995 TDMA Several 16-QAM 25 kHz Major Mobile Radio Standards in North America
Standard Year Of Introduction Multiple Access Frequency Band Modulation Channel Bandwidth JTACS Cellular 1988 FDMA 860-925 MHz FM 25 kHz PDC Cellular 1993 TDMA 810-1501 MHz P/4- DQPSK 25 kHz NTT Cellular 1979 FDMA 400/800 MHz FM 25kHz NTACS Cellular 1993 FDMA 843-925 MHz FM 12.5 kHz NTT Paging 1979 FDMA 280 MHz FSK 12.5 kHz NEC Paging 1979 FDMA Several FSK 10 kHz PHS Cordless 1993 TDMA 1895-1907 MHz P/4- DQPSK 300 kHz Major Mobile Radio Standards in Japan Type
Function Time Waveform w(t) Spectrum W(f) Fourier Transform pairs Rectangular rect(t/T) Triangular ( t /T) Unit Step {+1, t> 0 u(t) = {-1, t< 0 1/2d(f)+1/(j2pf) Signum {+1, t> 0 sgn(t) = {-1, t <0 1/(jpf) Constant 1 d(f) Impulse at t=t0 d(t-t0) e-2 j f t0 Sinc Sa(2pWt) 1/2W rect(f/2W) Phasor ej(w0 t+f) ejf (f-f0 ) Sinusoid cos(wct+f) 1/2e jfd(f-f c)+1/2e -jfd(f+f c ) Gaussian e- p (t/ t0 )^2 t0 e- p (f t0)^2 Exponential, One sided { e-t/T ,t>=0 { 0 ,t< 0 T/(1+j2pfT) Exponential, Two sided e-|t|/T 2T/(1+(2pfT)^2) Impulse Train k= d(t-kT) k=- n= f (f-nf ), where f = 1/T n=- T[Sa(pfT)] T[Sa(pfT)]2
Operation Function Fourier Transform Linearity A1w1(t)+A2w2(t) A1W1(f)+A2W2(f) Time Delay w(t-T d) W(f) e-jwTd Scale Change w(at) 1/|a| W(f/a) Conjugation w * (t) W * (-f) Duality W(t) w(-f) Real Signal Frequency Translation [w(t) is real] w(t)cos(wc t +q ) 1/2 [e jqW(f-f c )+e–jqW(f+f c )] Complex Signal Frequency Translation w(t)ejwct W(f-f c ) Band pass Signal Re{g(t)ejwct } 1/2[G(f-fc )+G *(-f-fc )] Differentiation d nw(t)/dt n (j2 pf) nW(f) Integration t-w( l)dl (j2pf)-1 W(f)+1/2W(0) d (f) Convolution w1 (t)*w2 (t) =-w ( l ).w (t- l )d l W1 (f)W 2 (f) Multiplication w1 (t)w2 (t) W1 (f)* W2 (f) = W1 (l ).W2 (f-l)dl Multiplication by t n tn w(t) (-j2p )-1d nW(f)/dnf Fourier Transform Theorems