Chapter 1 - Kỹ thuật thông tin vô tuyến

... high. 3. P b = 10 12 1 2γ = 10 12 γ = 10 12 2 = 5 × 10 11 (very high) 4. Geo: 35,786 Km above earth ⇒ RT T = 2×35786 10 3 c = 0.2386s Meo: 8,00 0- 20,000 Km above earth ⇒ RT T = 2×8000 10 3 c = 0.0533s ... case) ⇒ 0.5 2  2 1  × $1 + 0.5 2 × $1 +  6 1  0.8 × 0.2 5 × $0.2 +  6 2  0.8 2 × 0.2 4 × $0.4+  1 −  6 1  0.8 × 0.2 5 × $0.2 −  6 2  0.8 2 × 0.2 4 × $0.4  ×...

Ngày tải lên: 22/07/2013, 17:18

... log10(P r ) 10 * log10(d) G r = . 316 0 20 40 60 15 0 10 0 −50 0 50 10 * log10(P r ) 10 * log10(d) G r = .1 0 20 40 60 15 0 10 0 −50 0 50 10 * log10(P r ) 10 * log10(d) G r = . 01 0 20 40 60 0 10 0 ... plot (10 *log10(dnew) ,-2 0*log10(dnew)); plot (10 *log10(dnew) ,-4 0*log10(dnew)); end hold off 0 20 40 60 15 0 10 0 −50 0 50 10 * log10(P r ) 10 * log10(d) G r = 1 0 20 40 60...

Ngày tải lên: 22/07/2013, 17:18

... 0.8 1 1.2 1. 4 1. 6 1. 8 2 10 −5 0 5 fd = 1 Hz Envelope(dB) 0 0.2 0.4 0.6 0.8 1 1.2 1. 4 1. 6 1. 8 2 −20 10 0 10 fd = 10 Hz Envelope(dB) 0 0.2 0.4 0.6 0.8 1 1.2 1. 4 1. 6 1. 8 2 −20 10 0 10 fd = 10 0 ... 0.8 1 1.2 1. 4 1. 6 1. 8 2 −30 −20 10 0 1 Hz 0 0.2 0.4 0.6 0.8 1 1.2 1. 4 1. 6 1. 8 2 −30 −20 10 0 10 10 Hz 0 0.2 0.4 0.6 0.8 1 1.2 1. 4 1. 6 1. 8 2 −6...

Ngày tải lên: 22/07/2013, 17:18

...  ∞ γ 0  1 γ 0 − 1 γ  p(γ)dγ = 1 Evaluating this with p(γ) = 1 10 e −γ /10 , we have 1 = 1 10γ 0  ∞ γ 0 e −γ /10 dγ − 1 10  ∞ γ 0 e −γ /10 γ dγ (1) = 1 γ 0 e −γ 0 /10 − 1 10  ∞ γ 0 10 e −γ γ ... = 1 γ 0 − 1 γ j subject to the constraint ΣP j P = 1 11. S = 10 mW N 0 = .0 01 µW/Hz B = 10 MHz Now we compute the SNR’s as: γ j = |H j | 2 S N 0 B This gives: γ 1 =...

Ngày tải lên: 22/07/2013, 17:18

... alone, d = √ 10 0 2 + 500 2 = 10 0 √ 6 × 10 3 P e = 1 2 e −γ b ⇒ γ b = 13 .12 24 P γ N 0 B = 13 .12 24 ⇒ P γ = 1. 312 2 × 10 14 P γ P t =  √ Gλ 4πd  2 ⇒ 4.8488W (b) x = 1. 312 2 × 10 14 = 13 8.82dB P ... [0:. 01: 25]; gamma = 10 .^(gamma_db /10 ); M = 16 ; Ps_exact = 1- exp(2*log( ( 1- ((2*(sqrt(M) -1 ) )/(sqrt(M)))*Q(sqrt((3*gamma)/(M -1 ) ))))); Ps_approx = ((4*(sqrt(M) -...

Ngày tải lên: 22/07/2013, 17:18

... (4/pi)* ( 1- (1/ sqrt (16 )))^2*sum(sumvec2)*.0 01; 5 10 15 20 10 −9 10 −8 10 −7 10 −6 10 −5 10 −4 10 −3 10 −2 10 1 10 0 Ps avg Figure 6: Problem 22 23. MATLAB CODE: M = [1 2 4 8]; alpha = 2/3; g = 1. 5/ (16 -1 ) ; gammab_dB = [5: .1: 20]; ... = 10 .^(gammab_dB /10 ); Gamma=sqrt(gammab./(gammab +1) ); pb_mrc =(( ( 1- Gamma)/2).^2).*(( (1+ Gamma)/2).^0+2*( (1+ Gamma)/2). ^1)...

Ngày tải lên: 22/07/2013, 17:18

... (a) as γ 1 = 75.92 and γ 2 = 11 .08.  1 γ 0 − 1 γ 1 K  +  1 γ 0 − 1 γ 2 K  = 1 ⇒ 2 γ 0 = 1 + 1 γ 1 K + 1 γ 2 K ⇒ γ 0 = 1 1 + 1 K  1 γ 1 + 1 γ 2  = 1. 4649 which is less than both γ 1 and γ ... 0 is less than both γ 1 and γ 2 . Then  1 γ 0 − 1 γ 1  +  1 γ 0 − 1 γ 2  = 1 ⇒ 2 γ 0 = 1 + 1 γ 1 + 1 γ 2 ⇒ γ 0 = 1 1 + 1 γ 1 +...

Ngày tải lên: 22/07/2013, 17:18

... (9) (b) S =10 mW Signal power N = N 0 [1 2 × 10 MHz + 2 2 × 10 MHz + 0.5 2 × 10 MHz + 4 2 × 10 MHz] = 0. 212 5mW ∴ SNR = 47.0588 = 16 .73dB (c) T s = 0. 012 5µsec P b ≤ 0.2e 1. 5γ/M 1 or M ≤ 1 + 1. 5SNR −ln(5P ... If F(z) is of length 2 and monic, say F (z) = 1 − a 1 z then 1 F (z) = 1 + a 1 z 1 + a 2 1 z −2 + . . . where c 1 = a 1 , c 2 = a 2 1 , a 1 < 1 I...

Ngày tải lên: 22/07/2013, 17:18

... MATLAB for i = 1: length(n) pn(i) = (factorial(Nc -1 ) ./(factorial(n(i)).*factorial(Nc -1 - n(i))))... *alpha.^n(i)* ( 1- alpha).^(Nc -1 - n(i)); end sump = 0; for i = 1: length(n) f = ((G/sir0)-n(i )-. 247*Nc)/(sqrt(.078*Nc)); ... = 10 0e3; sigma_2 = 1e-9; P = 10 e-3; K = 10 ; ss = .0 01; alpha = 0:. 01: 1; theta = 0:ss :1; for i = 1: length(alpha) capvec = log2 (1+ (K*P* (1+...

Ngày tải lên: 22/07/2013, 17:18

Ngày tải lên: 14/10/2013, 22:36