課程名稱︰ 通信原理
課程性質︰ 系定複選必修
課程教師︰ 陳光禎
開課學院： 電機資訊學院
開課系所︰ 電機工程學系
考試日期（年月日）︰ 98.1.15
考試時限（分鐘）： 120分鐘
是否需發放獎勵金： 是，謝謝
（如未明確表示，則不予發放）
試題 :
1. [Equalizer, 20%]
Lat the sequence {x(nT)}, where T is the symbol duration, denote the input
applied to a tapped-delay-line equalizer. Please show that inter-symbol
interfetence is eliminated completely by the equalizer provided that its
frequency response satisfies the following condition and please design the
linear optimal receiver to overcome ISI.
H(f) = T / {Σ_k X(f-k/T)}
2. [Optimal Receiver, 30%]
Please consider the following equally likely binary signals s1(t) and s0(t)
during the time interval [0,3T]. The ovserved signal waveform is embedded in
AWGN with zero mean and 2-side p.s.d N0/2.
s1(t)的圖為方波，在[0,T]的值為1，[T,2T]為-1，[2T,3T]為1。
s0(t)也是方波，在[0,T/2]的值為-1，[T/2,3T/2]為1,[3T/2,5T/2]為-1,[5T/2,3T]為1。
(a) Please design the optimal receiver for such signaling. Hint: Please
consider signal space.
(b) Please find the BER in terms of Eb/N0. Hint: Please note signal energy.
3.[FSK,30%]
Suppose we employ an M-ary FSK modulation in AWGN channel with zero mean and
2-side p.s.d. N0/2. Let T be the symbol duration and we use non-coherent
demodulation for FSK.
(a) What is the minimum bandwidth to use such FSK modulation?
(b) If we use energy detection to demodulate FSK, please design the receiver.
Hint: Please note the filter bandwidth.
(c) What is the symbol error rate in terms of En/N0? Hint: Redundant phase.
4.[Phase Estimation, 20%] The receive waveform at the receiver can be
represented by r(t) = Acos(2πfct+θ) +n(t), where n(t) is AWGN with zero mean
and 2-side p.s.d. N0/2. To recover the carrier phase θ, please find the ML
optimal phase estimator. How can we improve the phase tracking performance?
--
※ 發信站: 批踢踢實業坊(ptt.cc)
◆ From: 140.112.244.81