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RF-LAN FOR SATELLITEBy

Hemanth kumar.S

Under the guidance of

Dr. Sambasiva Rao

1

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Agenda

Item 5

Literature survey

Implementation

Introduction

Advantages

Reference

Item 1

Item 3

Item 2

Item 4

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INTRODUCTION

Propulsionsystem

Acceleros

gyros

Reaction

wheels

Star sensor

Batteries

Earth sensor

Thermal control

Solargenerator

Power

distribution

paylod

DT system

Navigation

camera

GPS

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[1] Arbab Waheed Ahmad, Guochen Fan, Guodong Xu, "Implementation of

ZigBee-GSM based Home Security Monitoring and Remote Control

system" IEEE Transactions on Consumer Electronics, Vol.56 No. 4,

pp: 2241-2248,2010.

[2] Ali N. Akansu, "Walsh-Like Nonlinear Phase Orthogonal Codes for Direct

Sequence CDMA Communications" , IEEE transactions on signal

processing, VOL. 55, NO. 7, JULY 2007.

[3] Shaobin Li, Guochen Fan, Guodong Xu, "Application of Wireless Satellite

Bus in micro-satellite design" ,International Conference on Mechatronics

and Automation August 9 - 12, Changchun, China, 2009.

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CDMA TECHNIQUE

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Anti jamming capability

Interference rejection

Secure communication

Multipath protection

Bandwidth ofthe

transmittedsignal is much

greater thanthat of the

message thatmodulates the

carrier

Thetransmissionbandwidth is

determined by

a factorindependent

of themessage

bandwidth

DSSS

FHSS

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Multiplication with the code sequencewhich is of a higher bit rate.

The ratio of the code rate to theinformation bit rate is called both thespreading factor

To distinguish the information bit ratefrom the code rate, we call the code

rate, chipping rate.

SPREADING CODES

CRITERION

Balancedsequence

OrthogonalEqual runsof 0s and

1s

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Walsh code generator PRBS

Several spreading codes are popular for use in practical spread spectrum system

M-sequence code

Gold codes

Kasami codes &

barker codes

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Walsh codes are created out of Haddamard matrices andTransform.

In a family of Walsh codes, all codes are orthogonal to eacother and are used to create channelization

The seed matrix is,

to derive a set of four orthogonal Walsh sequences w0, w1, w2, and

w3, we only need to generate a Hadamard matrix of order 4, or22

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LFSR

Longer length code

1 1 1 1 0

0 1 1 1 00 0 1 1 0

0 0 0 1 1

1 0 0 0 0

0 1 0 0 0

0 0 1 0 1

1 0 0 1 1

1 1 0 0 0

0 1 1 0 1

1 0 1 1 0

0 1 0 1 1

1 0 1 0 1

1 1 0 1 1

1 1 1 0 1

1 1 1 1 0

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BASIC BLOCK DIAGRAM OF CDMA

In CDMA, each usersnarrowband signal is spread over

a wider bandwidth.

Each users narrowband signal isspread by a different widebandcode

Basic Block Diagram to Illustrate CDMA technique

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Approach-1

More BER

Simpler

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Approach-2

Less BER

Immune to

Channel noise

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BASIC OPERATIONS IN CDMA11/28/2012 14/20

S(t)= 2d(t)g(t)

S(t)= 2d(t)g(t)sin(2)

rcv(t)= 2d(t)g(t)sin 2

rcv(t)= 2d(t)g(t)(1-cos 4 )

rcv(t)= 2d(t)g(t)

rcv(t)= d(t)g(t)g(t)

/ /

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ILLUSTRATION TRANSMITTER

user

1

user

2

user

3

user

4

0

1

0

1

-1

+1

-1

+1

1 1 1 1

1 -1 1 -1

1 1 -1 -1

1 -1 -1 1

-1 -1 -1 -1

1 -1 1 -1

-1 -1 1 1

1 -1 -1 1

0 -4 0 0

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ILLUSTRATION RECIEVER

1 1 1 1

1 -1 1 -1

1 1 -1 -1

1 -1 -1 1

0 -4 0 0

0 4 0 0

0 -4 0 0

0 4 0 0

0 -4 0 0

-4 -1 0

4 +1 1

-4 -1 0

4 +1 1

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FDMA

Bandwidth is

divided intoseparate frequency

bands

Bandwidth limited

TDMABandwidth is time

shared

Bandwidth limited

CDMASimultaneous

datatransmissionusing coding

theory

Soft capacityInterference

limitedCombat

multipath fading

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2012-2013

Phase-1

Phase-2

Performance analysis

Implementation

Testing

AugJunMayAprMarFebDecNovoctSep Jan Jul

Literarure survey

Problem defination

Simulation of CDMA

Studying of ACF

Desiging PLL

Phase-3

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CDMA RF System Engineering by Samuel C.

Yang

CDMA Mobile Radio Design by John B. Groe

Lawrence E. Larson.

www.complextoreal.com

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THANK YOU