教材勘误

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Errata
Ch 2
On page 50 2.11 Varrall G is (1998), as on page 75, and not 1993 as typed here!
At some point the square root signs on Fig. 2.38 have been omitted: should be:

a
0101000110011101
0100000010001100

0110001010101110

0111001110111111
a2
a10

a18

eq (2.27), p. 31 Hf should be Hf2
It would be better to use exp(-jwct) as the complex form of the carrier. Then (2.7):
atRebtexpjctRebtcosctjsinct




Reb
ptcosctbqtsinctjbptsinctbqtcosc
t




b
ptcosctbqtsinc
t

(2.8):

atRebtexpjct



1
2
btexpjctbtexpjct


complex conjugate







(2.9):
A12btexpjctbtexpjct




expjtdt





1
2
btexpjctdtb*texpj

c



tdt











12Bc
B

c





noting that:
b*texpj

ctdtbtexpjctdt*B*c



Ch 3
Equation (3.12), p. 65, should be:

y
1

cos21tdt0T'1'

cos0tcos1tdt0T'0'










1
2
1cos21tdt0T'1'

1
2
cos10tcos10tdt0T'0'









T2'1'
T
2
sin

10


T



1
0


T

'0'








Prob 3.2, p 75. 221xxr should be xx21x2
Fig. 3.23 is a bit misleading. Would be better as:
2T
and with caption marked as h = 1.5 in this example
A simpler and more useful version of eq (3.16) normalises the result so that the peak p.s.d
is unity:

Gf
cos2fT

14fT

2

Problem 5.8 (p 139), does not give the noise standard deviation, which is required.
Suggest:

5.8. For the code illustrated in Fig. 5.12, the received symbol amplitudes are –0.11, -
0.21, 1.34. Find the log-likelihood ratios between the codeword 000 and each of
the other three codewords, for both hard and soft decision decoding (the latter
assuming a Gaussian noise channel with unit standard deviation and no
attenuation). Find also for soft decision decoding the log-likelihood ratio of each
bit.

Equation (5.43), p. 137, should be:
d
j


2dHjSN2dHjkEbTnN02T2d
Hj

kn2E
b

N
0

(5.43)
Ch 9
p 268 Caption for Fig 9.24 appears to be incomplete. Should be:
Figure 9.24. Filter responses for DFE for channel of Fig. 9.18, optimised for N0 = (a)
0, (b) 0.1 and (c) 5

Appendix 2
p. 347, l2 Inline equation should read Pdk1Pdk012
p. 348 sect A2.2 1. 1st bullet point should be "Calculate the four values of  from the
received signal using (A2.9)"