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【单选题】
妊娠期母体循环系统变化正确的是
A.
心脏容量至妊娠末期约增加30％
B.
心排出量自妊娠20逐渐增加
C.
心排出量至妊娠32～34高峰
D.
妊娠晚期舒张压一般升高
E.
妊娠晚期心率休息时每分钟增加5次
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参考答案：
举一反三
【判断题】In a frequency selective fading channel, the received signal can be expressed by【图片】, where x(t) and n(t) denote the transmit signal and AWGN, and【图片】 denotes the fading coefficient.
A.
正确
B.
错误
查看完整题目与答案
【单选题】在经验之塔中,最高层是( )
A.
言语和视觉符号
B.
录音广播
C.
观摩示范
D.
设计的经验
查看完整题目与答案
【判断题】因QP=ΔH，QV=ΔU，所以QP与QV都是状态函数。()
A.
正确
B.
错误
查看完整题目与答案
【判断题】For AWGN channel, QPSK with Gray mapping can achieve the same bit error rate as a coherent BPSK in white Gaussian noise, but the bandwidth efficiency of BPSK is twice that of QPSK.
A.
正确
B.
错误
查看完整题目与答案
【单选题】About QPSK, the incorrect statement isa. The SER performance of QPSK in an ideal AWGN channel is equal to that of BPSKb. Each QPSK symbol corresponds to two bits.c. The spectrum efficiency of QPSK is ...
A.
只有这个说法是错的，但答案是对的
B.
答案不对
C.
答案不对
D.
答案不对
查看完整题目与答案
【判断题】For AWGN channel, 16-PSK requires less signal energy than the 16-FSK for the fixed noise power spectrum density and symbol error rate.
A.
正确
B.
错误
查看完整题目与答案
【多选题】Regarding the ML decision rule for signal transmissions over AWGN channel, the statements _______________ are correct.
A.
The ML decision rule is to choose the message point closest to the received signal point.
B.
The ML decision rule always equals to the MAP rule.
C.
The MAP and ML decision rules can be conditionally equivalent.
D.
The ML decision rule can minimize the probability of error.
查看完整题目与答案
【多选题】Comparing QPSK and BPSK transmitted over AWGN channel, _______________.
A.
QPSK can achieve the same bit error rate as BPSK.
B.
QPSK can achieve the same symbol error rate as BPSK.
C.
the bandwidth efficiency of QPSK is the same as that of BPSK.
D.
the bandwidth efficiency of QPSK is twice that of BPSK.
查看完整题目与答案
【多选题】For a given signal constellation, the average probability of symbol error incurred in maximum likelihood signal detection over an AWGN channel is invariant to the _________________ of the signal const...
A.
compression
B.
translation
C.
expansion
D.
rotation
查看完整题目与答案
【简答题】（九）用量角器画一画．&n1qp;&n1qp;&n1qp;&n1qp; 中0°、九65°&n1qp;&n1qp;&n1qp;&n1qp;&n1qp;&n1qp;&n1qp;&n1qp;&n1qp;&n1qp;&n1qp;&n1qp;&n1qp;&n1qp;&n1qp;&n1qp;&n1qp; （2）用一副三角板拼出下面度数二角，并画出来． 65°、九20°．
查看完整题目与答案
相关题目：
【判断题】In a frequency selective fading channel, the received signal can be expressed by【图片】, where x(t) and n(t) denote the transmit signal and AWGN, and【图片】 denotes the fading coefficient.
A.
正确
B.
错误
查看完整题目与答案
【单选题】在经验之塔中,最高层是( )
A.
言语和视觉符号
B.
录音广播
C.
观摩示范
D.
设计的经验
查看完整题目与答案
【判断题】因QP=ΔH，QV=ΔU，所以QP与QV都是状态函数。()
A.
正确
B.
错误
查看完整题目与答案
【判断题】For AWGN channel, QPSK with Gray mapping can achieve the same bit error rate as a coherent BPSK in white Gaussian noise, but the bandwidth efficiency of BPSK is twice that of QPSK.
A.
正确
B.
错误
查看完整题目与答案
【单选题】About QPSK, the incorrect statement isa. The SER performance of QPSK in an ideal AWGN channel is equal to that of BPSKb. Each QPSK symbol corresponds to two bits.c. The spectrum efficiency of QPSK is ...
A.
只有这个说法是错的，但答案是对的
B.
答案不对
C.
答案不对
D.
答案不对
查看完整题目与答案
【判断题】For AWGN channel, 16-PSK requires less signal energy than the 16-FSK for the fixed noise power spectrum density and symbol error rate.
A.
正确
B.
错误
查看完整题目与答案
【多选题】Regarding the ML decision rule for signal transmissions over AWGN channel, the statements _______________ are correct.
A.
The ML decision rule is to choose the message point closest to the received signal point.
B.
The ML decision rule always equals to the MAP rule.
C.
The MAP and ML decision rules can be conditionally equivalent.
D.
The ML decision rule can minimize the probability of error.
查看完整题目与答案
【多选题】Comparing QPSK and BPSK transmitted over AWGN channel, _______________.
A.
QPSK can achieve the same bit error rate as BPSK.
B.
QPSK can achieve the same symbol error rate as BPSK.
C.
the bandwidth efficiency of QPSK is the same as that of BPSK.
D.
the bandwidth efficiency of QPSK is twice that of BPSK.
查看完整题目与答案
【多选题】For a given signal constellation, the average probability of symbol error incurred in maximum likelihood signal detection over an AWGN channel is invariant to the _________________ of the signal const...
A.
compression
B.
translation
C.
expansion
D.
rotation
查看完整题目与答案
【简答题】（九）用量角器画一画．&n1qp;&n1qp;&n1qp;&n1qp; 中0°、九65°&n1qp;&n1qp;&n1qp;&n1qp;&n1qp;&n1qp;&n1qp;&n1qp;&n1qp;&n1qp;&n1qp;&n1qp;&n1qp;&n1qp;&n1qp;&n1qp;&n1qp; （2）用一副三角板拼出下面度数二角，并画出来． 65°、九20°．
查看完整题目与答案
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