25-08-2017, 09:32 PM
Different Techniques to Reduce the PAPR in OFDM System
[attachment=65719]
ABSTRACT
Orthogonal Frequency Division Multiplexing
(OFDM) is well known Technique for transmitting
large data Over Radio waves. Its main disadvantage
is PAPR (Peak to average power ratio) nothing but
several sinusoidal leads. This paper presents
Reduction PAPR using all proposed techniques . This
Proposed techniques shows better performance for
reduction in PAPR any technique can be used
according to performance.
Keywords: - Orthogonal Frequency Division
Multiplexing (OFDM), Peak to Average Power Ratio,
Problems & Solutions.
INTRODUCTION
OFDM is multicarrier multiplexing access Technique for
Transmitting Large data over Radio waves. Next mobile
Generation system is expected to provide high data rate
to meet the requirement for future multimedia
applicaton. Minimum data rate required for the 4G
System is 10-20Mbps & at least 2Mbps in moving
vehicles. And modulation technique adopted by 4G
mobile system is OFDM. One of the major problems
observed in OFDM system is PAPR (Peak to Average
Power Ratio).This PAPR must be Reduce for efficient
transmission. Different techniques can be used for reduce
PAPR in OFDM system. In this Paper We describe all
techniques which can be used to reduce PAPR in OFDM
system. All the techniques performs best in reduction.
this paper contains an overview of all techniques to
reduce PAPR in OFDM system.
I. OFDM
OFDM is generally used for the Digital Television
Broad casting (DTB), Digital Audio Broadcasting
(DAB) & Digital Video Broad casting (DVB) like
this..OFDM is the technique which divide available
spectrum in many carriers and each carrier will modulate
by low data rate stream. OFDM uses the spectrum much
more efficiently by spacing the Channels more closely
together. This can be done by making all the carriers
orthogonal to one another, preventing interference
between the closely.
FIG.1. MULTICARRIER TRANSMISSION TECHNIQUE
II. PAPR PROBLEM & REQUIREMENT OF
REDUCTION
In previous paragraph basics of OFDM (Orthogonal
frequency division multiplexing) has been discussed
.actually OFDM system is very efficient & marvelous
technique in its manner, but when there is a merits
demerits also available. So here we discuss one of the
major drawbacks of the OFDM system. Drawback is
high PAPR (Peak-to-Average Power ratio). PAPR means
randomly sinusoidal leads occurred during transmission
of the OFDM signal. So in this chapter we discuss basics
of PAPR, why it is created & what the proposed solution
are for reduce it.
So as per the introduction of PAPR we can judge that to
reduce the PAPR is most important point in the OFDM
system. Because of when we are talking about the high
speed data communication in real life like video calling,
high speed internet access, and also main point is that
high speed data access up to 2mbps while moving on the
vehicle at 100km/h, digital video broadcasting (DVB),
Microwave terrestrial television, Digital audio
broadcasting (DAB), 4G system, hyper LAN. So this
most type of communication systems required high data
rate. But problem occurs like PAPR in OFDM system
prevent these types of facilities in the real life. So to
reduce it is most important.
Partial transmit sequence (PTS)
Partial transmit sequence is also one of the Probabilistic based. Main idea of this scheme is data block divide into non overlapping sub block with independent rotation factor. This rotation factor generates time domain data with lowest amplitude. This is modified technique of SLM scheme. And gives better performance than SLM. Because of differential modulation no needs to transmit the side information. 3.1.5 Linear block codes This technique also known as standard array of linear block codes. in this scheme distinct U signal is transmitted along with transmitted sequence. U distinct signal is used constructed using proper select co –set words. Using scrambling codes no needs to transmit side information and received signal can be easily decoded. Main thing is that to select standard array of codes to reduce the PAPR. This technique also modification of the SLM techniques. In this transmitted signal with minimum PAPR using scrambling code. Technique has better performance than SLM technique. 3.1.6 Interleaving In this technique highly correlated data frame .in this adaptive technique also reduces the complexity. Adaptive interleaving is to establish an early terminating threshold. So the searching process is terminated when the value of PAPR reaches below the threshold value.so, these low threshold force the AIL to search for all interleaving sequence. This technique is less complex than PTS.
CONCLUSION
Basically as per the information about all above described techniques to reduce the PAPR in OFDM system all techniques is different in their way.and using each technique PAPR will be reduced at some what level. To reduce the PAPR any technique can be used.
[attachment=65719]
ABSTRACT
Orthogonal Frequency Division Multiplexing
(OFDM) is well known Technique for transmitting
large data Over Radio waves. Its main disadvantage
is PAPR (Peak to average power ratio) nothing but
several sinusoidal leads. This paper presents
Reduction PAPR using all proposed techniques . This
Proposed techniques shows better performance for
reduction in PAPR any technique can be used
according to performance.
Keywords: - Orthogonal Frequency Division
Multiplexing (OFDM), Peak to Average Power Ratio,
Problems & Solutions.
INTRODUCTION
OFDM is multicarrier multiplexing access Technique for
Transmitting Large data over Radio waves. Next mobile
Generation system is expected to provide high data rate
to meet the requirement for future multimedia
applicaton. Minimum data rate required for the 4G
System is 10-20Mbps & at least 2Mbps in moving
vehicles. And modulation technique adopted by 4G
mobile system is OFDM. One of the major problems
observed in OFDM system is PAPR (Peak to Average
Power Ratio).This PAPR must be Reduce for efficient
transmission. Different techniques can be used for reduce
PAPR in OFDM system. In this Paper We describe all
techniques which can be used to reduce PAPR in OFDM
system. All the techniques performs best in reduction.
this paper contains an overview of all techniques to
reduce PAPR in OFDM system.
I. OFDM
OFDM is generally used for the Digital Television
Broad casting (DTB), Digital Audio Broadcasting
(DAB) & Digital Video Broad casting (DVB) like
this..OFDM is the technique which divide available
spectrum in many carriers and each carrier will modulate
by low data rate stream. OFDM uses the spectrum much
more efficiently by spacing the Channels more closely
together. This can be done by making all the carriers
orthogonal to one another, preventing interference
between the closely.
FIG.1. MULTICARRIER TRANSMISSION TECHNIQUE
II. PAPR PROBLEM & REQUIREMENT OF
REDUCTION
In previous paragraph basics of OFDM (Orthogonal
frequency division multiplexing) has been discussed
.actually OFDM system is very efficient & marvelous
technique in its manner, but when there is a merits
demerits also available. So here we discuss one of the
major drawbacks of the OFDM system. Drawback is
high PAPR (Peak-to-Average Power ratio). PAPR means
randomly sinusoidal leads occurred during transmission
of the OFDM signal. So in this chapter we discuss basics
of PAPR, why it is created & what the proposed solution
are for reduce it.
So as per the introduction of PAPR we can judge that to
reduce the PAPR is most important point in the OFDM
system. Because of when we are talking about the high
speed data communication in real life like video calling,
high speed internet access, and also main point is that
high speed data access up to 2mbps while moving on the
vehicle at 100km/h, digital video broadcasting (DVB),
Microwave terrestrial television, Digital audio
broadcasting (DAB), 4G system, hyper LAN. So this
most type of communication systems required high data
rate. But problem occurs like PAPR in OFDM system
prevent these types of facilities in the real life. So to
reduce it is most important.
Partial transmit sequence (PTS)
Partial transmit sequence is also one of the Probabilistic based. Main idea of this scheme is data block divide into non overlapping sub block with independent rotation factor. This rotation factor generates time domain data with lowest amplitude. This is modified technique of SLM scheme. And gives better performance than SLM. Because of differential modulation no needs to transmit the side information. 3.1.5 Linear block codes This technique also known as standard array of linear block codes. in this scheme distinct U signal is transmitted along with transmitted sequence. U distinct signal is used constructed using proper select co –set words. Using scrambling codes no needs to transmit side information and received signal can be easily decoded. Main thing is that to select standard array of codes to reduce the PAPR. This technique also modification of the SLM techniques. In this transmitted signal with minimum PAPR using scrambling code. Technique has better performance than SLM technique. 3.1.6 Interleaving In this technique highly correlated data frame .in this adaptive technique also reduces the complexity. Adaptive interleaving is to establish an early terminating threshold. So the searching process is terminated when the value of PAPR reaches below the threshold value.so, these low threshold force the AIL to search for all interleaving sequence. This technique is less complex than PTS.
CONCLUSION
Basically as per the information about all above described techniques to reduce the PAPR in OFDM system all techniques is different in their way.and using each technique PAPR will be reduced at some what level. To reduce the PAPR any technique can be used.