Spread Spectrum

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    05-Aug-2015

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105100092158 :

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BSS79542368

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1- - . . 1Bs . . duplexing ]2[. Duplexing . 2 FDD . duplex 3 duplexer BS duplex . . 1 TDD . . 1 FDD TDD .

1: ( FDD . ( TDD .1 Base Station 2 Frequency Division Duplexing 3- Simplex 1- Time Division Duplexing

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TDD duplexer . FDD Tradeoff TDD . FDD . -1 100dB . . RF. TDD - . . full duplex .

1-1- 2 ) (FDMA 3 ) (TDMA 4 ) (CDMA . . : . . FDD - . . Duplexer - - .2- Transceiver 1- Frequency Division Multiple Access 2- Time Division Multiple Access 3- Code Division Multiple Access

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FDMA . FDD ) ( FDMA/FDD . TDMA . . TDMA FDD TDD TDMA . TDMA/TDD TDMA/FDD . : . . . . TDMA . CDMA . CDMA TDMA FDD multiplexing TDD . TDMA FDMA CDMA : Packet Radio 1 . 1 .

)1- SDMA (space division multiple access

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AMPS Gsm USDC JDC 2CT 59-FS

FDMA/FDD TDMA/FDD TDMA/FDD TDMA/FDD FDMA/FDD CDMA/FDD

1:

2- FDMA 2 ]2[. . . FDD

2: FDMA

. - . FDMA : FDMA . FDMA - .

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BS 1MS . . FDMA 2 . FDMA TDMA . FDMA TDMA ) overhead 3 (Framing . FDMA duplexer . FDMA BS . AMPS FDMA/FDD. 4 . 45 MHz . handoff AMPS . BS MS MS BS . FDMA :=N Bt 2 Bguard Bc

Bt Bguard BC .

3- TDMA TDMA . 31 Mobile Station 2- Equalization 3- Synchronization 4 Single channel

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]2[. frame ) frame N (. TDMA buffer-and-burst . . FDMA FM TDMA .

3: TDMA

4 Packet preamble tail . frame . frame .

4: TDMA Frame

TDMA/TDD . TDMA/FDD frame

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. TDMA/FDD duplexer. TDMAframe preamble BS . 1 frame . TDMA TDMAframe . TDMA : TDMA - . frame ... . TDMA burst . . TDMA handoff . BS . TDMA . TDMA duplexer . FDD duplexer TDMA . 1 TDMA FDMA . TDMA . - . overhead burst TDMA . TDMA burst .

1 Gaurd Time 1 Adaptive equalization

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overhead FDMA . TDMA . .

TDMA

TDMA . n f frame frame . frame . . n f. over head frame :bOH = N r br + N t bp + N t bg + N r bg

N r burst Nt frame br frame overhead burst bp overhead preamble . bg Gaard. bT frame-bT = T f .R

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T f frame R . y f FRAME : 1( = y f bOH %001 ) bT TDMA

TDMA TDMA :

01

=N

) m( Btot 2 Bguard BC

m TDMA . bleed over .

4- CDMA CDMA 1 . . . " " . CDMA " " ]1[. CDMA . . : 1- . 2- . - . . := GP Bt Bi

1 Spreading Code

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Bt Bi . . . . . 1- : . Correlate

1 . . ) ( . . ) 5(a . )1( )1( .

5:

1 - Despread

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2- : . . . . . . CDMA . 3- 1: . 4- : Correlate . 6 . S i . . ) ( .

6 :

1 - Privacy

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5- : . CDMA 7 . .

7: CDMA

: . : . : burst . burst . : . . CDMA : TDMA MC MT . MC- CDMA MT-CDMA .

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4-1 Direct Sequence DS-CDMA . . . . . DC-CDMA ]1[ ]3[ ]4[ . 8 DS-CDMA . RF . . Chips 1+ 1- . Chiprate Chiprate .

8: DS-SS

PSK D-PSK BPSK MSK . BPSK 9 . DS-SS 01 . chip rate . 01 Code chip . chip rate . 01 . 11 . Local

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. . Synchronization/Tracking . .

9: DS-SS

01: BPSK

11: DS-SS

. CDMA LPI. DS-CDMA :

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1- : DS

. - . . - . 2- : ] [ Tc, Tc . Tc chip. ) (2Tc . 3- : Local. . 4- : DS . DS . DC-CDMA )+( )-( : + . + ) ( . + DS . + .

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. . 01 02 MHz . BS . BS BS . - BS BS . .

4-2 Frequency Hopping FH-CDMA . T . . hop-set ]1[ ]3[ ]4[. FH-SS DS-SS . DS FH . . DS-SS FH-SS 21 .

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21 : / DS FH

FH 2 . DS . 2 FH-SS- . DS 1 FH . FH-CDMA 31 .

31: - FH-CDMA

. . . . . Synchronization/Tracking .

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FH-CDMA . F-FH . . S-FH - . . ) (S-FH hopping . DS-CDMA -FH

CDMA . : . 1- : 1 F-FH CDMA2 S-FH . F-FH . . S-FH . . . 2- : F-FH CDMA . - . hopping . DS- CDMA .

- Fast Frequency Hopping 2- Slow Frequency Hopping

02

3- : hopping . GP hopping ) : GP 1 ( hopping GP

. GP . 4- : FH . . . DS . FH-CDMA : + FH-CDMA DS-CDMA. hopping hop time chip time DS-CDMA. -FH

CDMA . + FH . . + . BS BS BS . FH - DS. + FH DS .

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. . - hopping .

4-3 Time Hopping TH-CDMA burst . frame frame M - . frame M . ]1[ ]3[ ]4[. M Ts Ts M TH-CDMA 41 . 51 TH-CDMA - . 51 21 TH-CDMA . FH-CDMA .

41: - TH-CDMA

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51: / TH-CDMA

CDMA TH-CDMA : 1- : TH-SS FH-SS . Timehopping . . - . TH-CDMA CDMA frame frame . 2- : TH-CDMA . . . 3- : TH-CDMA . 1 1 . GP GP

GP . 4- : TH-CDMA . -

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. . TH- CDMA : + . FH-CDMA + Peak-power . burst . + FH-CDMA . BS BS . .

4-4- Hybrid-CDMA CDMA . : DS/FH/TH FH/TH DS/TH DS/FH CDMA TDMA CDMA/TDMA MC-CDMA ]1[ ]3[ ]4[ . . DS/FH anti multipath DS FH - . . DS/FH

CDMA 71 . DS . . Code Clock .

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61: Hybrid DS-FH

4-5 1 0 1 : 1- . 2-

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