Arjun LOS Microwave Communication

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LOS MICROWAVE

COMMUNICATIONPresented by

Arjun KR(CYS14 !"

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MICROWAVES# M$%r&' )es re *&r+ &* e,e%tr&+ -net$% r d$ t$&n '$t.

' )e,en-t.s r n-$n- *r&+ s ,&n- s &ne +eter t& ss.&rt s &ne +$,,$+etre/ '$t. *re0uen%$es bet'een !M 2 ( 3! 2" nd ! 2

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MICROWAVE USES5# M$%r&' )e uses

o C&++un$% t$&no N )$- t$&no R d r o s te,,$teo M$%r&' )e &)ens

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LINE O6 SI T

What does Line of Sight (LoS) mean?

Examples:6M r d$&7 +$%r&' )e nd s te,,$te tr ns+$ss$&n ree8 +9,es &* ,$ne:&*:s$-.t %&++un$% t$&n3

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O9t$% , LOS ; R d$& LOSO9t$% , LOS5 O9t$% , LOS()$su , LOS" %&ns$ders &n,y &9t$% , )$s$b$,$ty3

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O9t$% , LOS ; R d$& LOSR d$& LOS5 R d$& L&S %&ns$ders t.e %&n%e9t &* 6resne,<s e,,$9s&$ds

nd t.e$r %,e r n%e %r$ter$ 3

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LOS Impairments# Attenuation - Strength of signal falls off with distance# Free space loss# Noise

# Atmospheric absorption# Multipath# Thermal noise

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Attenuation# Strength of signal falls off with distance over transmission

medium# Attenuation factors for unguided media

# !eceived signal must have sufficient strength so that circuitr" in thereceiver can interpret the signal

# Signal must maintain a level sufficientl" higher than noise to be receivedwithout error

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Free Space Loss# Free space loss# isotropic antenna

P t $ signal power at transmitting antenna

P r $ signal power at receiving antenna

λ $ carrier wavelengthd $ propagation distance between antennas

c $ speed of lightwhere d and λ are in the same units %e&g&# meters'

( ) ( )(

(

(

())

c

fd d

P

P

r

t π

λ

π ==

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Thermal Noise# Thermal noise due to agitation of electrons# *resent in all electronic devices and transmission media# +annot be eliminated

# Function of temperature# *articularl" significant for satellite communication

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Thermal Noise# Amount of thermal noise to be found in a bandwidth of , . in

an" device or conductor is

N / $ noise power densit" in watts per , . of bandwidth

0 $ 1olt.mann2s constant $ ,&34/3 5 ,/ -(3 678 T $ temperature# in 0elvins %absolute temperature'

( )97-.0 / T N =

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Impairments due to Atmospheric condition

# =ue t& 'e t.er t.e +$%r&' )e %&++un$% t$&n re**e%ted3

# R $ndr&9s nd . $,st&nes re s$+$, r $n s$2e t& t.e' )e,en-t. &* .$-.er:*re0uen%y +$%r&' )es3 A r $nst&r+% n b,&%> +$%r&' )e %&++un$% t$&n7 9r&du%$n- %&nd$t$&n % ,,ed r $n * de3 T& ,&% te $n%&+$n- st&r+s7'e t.er r d r de,$ber te,y uses s.&rter:' )e,en-t.+$%r&' )es t& $n%re se $nter %t$&n '$t. r $n3

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:iversit" Techni;ues-<rror correction# :iversit" is based on the fact that individual channels

e=perience independent fading events# Space diversit" > techni;ues involving ph"sical transmission path

# Fre;uenc" diversit" > techni;ues where the signal is spread outover a larger fre;uenc" bandwidth or carried on multiplefre;uenc" carriers

# Time diversit" > techni;ues aimed at spreading the data outover time

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T ANK YOU