Digital Signal Processing Reference
In-Depth Information
INPUT DATA for SPECTRAL PARAMETERS of a SYNTHESIZED TIME SIGNAL or FID
Argand Plot for Input Complex Frequencies
ν k : x
Absolute Values of Input Amplitudes |d k | : x
0
0.25
13
21
19
18
6
11
B 0 =1.5T
d k = |d k |e i φ k |d k | , φ k = 0 (k = 1,2,...,25)
15
10
22
16
7
24
20
0.05
0.2
12
9
8
5
14
23
17
6
2
0.1
0.15
4
3
25
1
H 2 O
7
15
Lip
0.15
16
0.1
8
3
9
1
H 2 O
22
17
14
12
Lip
25
5
0.2
0.05
20
19
10
4
21
24
B 0 =1.5T
23
18
11
0.25
2
13
0
5
4
3
2
1
5
4
3
2
1
(i) Re(
ν k ) (ppm)
(iv) Chemical shift (ppm)
Argand Plot for Input Signal Poles z −1
k
Argand Plot for Input Signal Poles z k
0
0
25
25
B 0 =1.5T
Arc of the unit circle ( line)
B 0 =1.5T
24
24
−0.2
0.2
23
22
Arc of the unit circle ( line)
Input harmonic variables (dots)
23
21
22
20
21
−0.4
0.4
19
20
18
z k = e 2i πτ ν k
19
17
|z| < 1
16
18
14
15
17
−0.6
0.6
|z| < 1
16
13
12
15
10
11
Input
harmonic
variables (dots)
z −1
14
9
13
8
7
−0.8
12
0.8
6
5
4
3
11
2
10
1
9
|z| > 1
8
7
6
−1
5
1
k = e −2i πτ ν k , |z| > 1
1
4
2
3
1
0.75
0.5
0.25
0
1
0.75
0.5
0.25
0
(v) Re(z −1
k
(ii) Re(z k )
)
K
d k z n
k , z k = e 2i πτ ν k (K = 25)
K
d k z n
k , z k = e 2i πτ ν k (K = 25)
Time Signal: c n =
Σ k=1
Time Signal: c n =
Σ k=1
2
2
Real part of time signal c n or FID
Imaginary part of time signal c n or FID
1.5
1.5
B 0 =1.5T
B 0 =1.5T
1
1
0.5
Bandwidth = 1000 Hz
0.5
Bandwidth = 1000 Hz
0
0
−0.5
N = 1024, τ = 1 ms
−0.5
N = 1024, τ = 1 ms
−1
−1
0
250
500
750
1000
1250
0
250
500
750
1000
1250
(iii) Time n (in units of sampling rate τ )
(vi) Time n (in units of sampling rate τ )
FIGURE 3.1
Argand plot for the input complex frequencies ν k and a graphical display of
the absolute values of amplitudes d k =|d k |: panels (i) and (iv). Argand plots
for the input signal poles or harmonic variables z k and their inverses z k :
panels (ii) and (v). Real Re(c n ) and imaginary Im(c n ) part of the input time
signal{c n }or FID as a sum of 25 damped complex exponentials with constant
amplitudes d k : panels (iii) and (vi).
 
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