Sponsored Links
This presentation is the property of its rightful owner.
1 / 87

第四讲 PowerPoint PPT Presentation


  • 106 Views
  • Uploaded on
  • Presentation posted in: General

第四讲. 4. 数据通信的主要技术指标. 数据通信的主要技术指标有数据传输速率、传输延迟、信道带宽、信道容量、数据传输的误码率等,这些指标是衡量数据传输的 有效性和可靠性 的参数。 有效性 主要由数据传输速率、传输延迟、信道带宽和信道容量等指标来衡量。 可靠性 一般用数据传输的误码率指标来衡量。. (1) 数据传输速率 数据传输速率是指单位时间内传输信息量的多少。它是衡量数据传输有效性的主要指标。 数据传输速率通常用 波特率 和 比特率 来表示。.

Download Presentation

第四讲

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript



4.


(1)


: (Baud)T()

Rs1/T (Baud)

1


(b/sbps)

Rb(1/T)log2N (bps)

TNRb


N21

Rb1/T (bps)

Rb Rslog2N (bps)

log2N


164Kbps 30048*10

t=8*10*300*4/64k


Pe Ne/N

NeNPe



(300,000km2/3)


21000km3kbits20kbps60kbps? (200,000km/s300,000km/s)


3/20=150ms

3/60=50ms

1000/(2*105)=5ms

36000*2/(3*105)=240ms

150+5=155ms

50+240=290ms


(2)

(b/s)



C2 F log2N

FNC()

C2 F log2N (bps)


()

CF log2(1S/N)


36MHZ4

C= 2*6M*log24=24Mbps


44KHZ830dB

C2 F log2N=2*4K*log28=24Kbps

dB10lgS/N

10lgS/N=30 S/N=103

CF log2(1S/N)= 4K*log21001=40Kbps


5.

(1)



(a)

(b)

(c)


(2)



01101001

01101001

0

1

1

0

1

0

0

1

01101001


(3)


  • DTE


6.


2. 2 1.

1

  • ()



(2)

  • ()


(3)



2.



(1)


  • ()


  • 1AM(ASK)

    2FM(FSK)

    3PM(PSK)

  • f(t)Asin(t+)A


  • ASK

  • ASK


ASK

ASK


  • FSK()(10)

  • FSK

  • FSK


1

0

1 1

0 0

1

0

FSK


  • PSK()(10)


1

0

1 1

0 0

1

0

PSK


(2)


(a)

(b)


(a)

(b)


01


1 0 1 0 0 1 1 0


10


0 1 0 1 1 0 0 1


(3)

  • (PCM)(M)

  • PCM


  • F f (F2f)


  • 264,128, 256


  • PCM


011 000 001 010 101 111 110 100

PCM


3.


n

n

1

n



(1) (FDM)



  • FDM


f

n fn

...

3 f3

2 f2

1 f1

t


(2) (TDM)


f

A

A B C D A B C D A BC D A B CD

t


  • (STDM)(ATDM)


(STDM)


(ATDM)


(3) (CDM)


  • CDMCDMCDM


  • CDM



D

B1

B2

B2

B1

D



(4) (WDM)

  • WDM


  • ,



4.




0 1 0 0 0 0 0 1 0

1

2

3

4


  • ()(SYN)SYN


  • ()(0111110)



S S S

Y Y Y

N N 1 2 N N

(a)

01111110 01111110

(b)





  • Login