MIMO-OFDM for 4G network

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  • BER Analysis and Performance of MIMO-OFDM

    System using BPSK Modulation Scheme

    For Next Generation Communication Systems

    Presented by: Mr. NIMAY CHANDRA GIRI

    Dept. of ECE

  • CONTENTS

    OBJECTIVE

    INTRODUCTION

    LITERATURE REVIEW

    MIMO TRANSMITTER & RECIEVER WITH RESULTS

    BPSK SYSTEM

    OFDM TECHNIQUE WITH RESULTS

    MIMO-OFDM SYSTEM

    SINGLE-CARRIER VS. MULTI-CARRIERS

    ADVANTAGES

    APPLICATION

    CONCLUSION

    FUTURE SCOPE

    REFERENCES

    PUBLICATION

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  • OBJECTIVE

    MIMO System: high data rates & increased capacity of the system

    OFDM Technique: reduced Multi path fading, ICI and ISI &

    provide Multi-carrier Orthogonal Signals.

    BPSK Modulation: Long distance transmission & used in each

    block of IDFT/IFFT of MIMO-OFDM model for mapping data

    streams.

    In this thesis Work, I compare the BER vs. SNR of MIMO-OFDM

    System using BPSK modulation, and performance of MIMO-

    OFDM system for 4G networks.

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  • INTRODUCTION MIMO-OFDM is a hot topic in today modern wireless communication since all

    wireless technologies like PAN, LAN, W-LAN, MAN, W-MAN & WAN.

    In the 1980s, MIMO-OFDM has been studied for high-speed transmission.

    MIMO System have multiple inputs and multiple outputs antennas.

    Multiplexing Gain => Spectral efficiency increases

    Diversity Gain => Combats Fading

    Interference Reduction Gain => Capacity increases

    o OFDM = Orthogonal FDM ( It was invented during World War-II, 1939-194580Hz of frequency used)

    o OFDM is a combination of Modulation & Multiplexing techniques.

    OFDM is a multicarrier block transmission system.

    Block of N symbols are grouped and sent parallely.

    No interference among the data symbols sent in a block.

    MIMO System and OFDM Modulation Technique

    Air-interface (ICI & ISI) solutions

    More Flexibility, Capacity & Efficiency

    More numbers of carriers

    Increase data rates and SNR with reducing BER.

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  • LITERATURE REVIEW

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    Title of Papers Authors name Year Work done

    Performance analysis of

    various equalizer for ISI

    reduction in MIMO-

    OFDM system.

    Yashvant Dhiwar, Rakesh

    Mandal

    2014 ISI reduction using

    Equalization technique

    (ZF, MMSE)

    Analysis Of Reduction In

    Complexity Of MIMO-

    OFDM System.

    Sabitha Gauni, Kumar

    Ramamoorthy

    2014 CFO estimation and

    correction by the help of

    ML estimator.

    Design of MIMO OFDM

    SDM Systems for High

    Speed Data

    Transmission

    Betsy Jose, Mr. B. Satish

    Kumar

    2014 BER reduction and high

    data rates by using 2*2

    MIMO-OFDM system,

    MATLAB

    BER analysis of various

    channel equalization in

    OFDM based MIMO

    CDMA system

    Husnul Ajra,

    Md. Zahid Hasan,

    Md. Shohidul Islam

    2014 using QO-STBC method

    for channel equalization &

    BER reduction

    Bit Error Rate

    Performance of BPSK

    Modulation and OFDM-

    BPSK with Rayleigh

    Multipath Channel

    M. Divya

    2013 BER performance is

    analyzed using BPSK &

    OFDM-BPSK modulation

    technique

  • MIMO ANTENNAS CONFIGURATION

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    Here MT transmit and MR receive antennas with input data stream is S and output

    data stream is Y.

    16/07/2014

  • MIMO SYSTEM MODEL

    y = Hs +

    User data

    stream y.

    .

    User data

    stream s.

    .

    .

    .Channel

    Matrix H

    s1

    s2

    sMT

    s

    y1

    y2

    yMR

    yTransmitted

    vectorReceived

    vector

    .

    .

    h11

    h21

    Where hij is a Complex Gaussian random

    variable that models fading gain

    between the ith transmit and jth

    receive antenna

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    j

  • SHANNONS CHANNEL CAPACITY (C)

    Given a unit of BW (Hz), the max error-free transmission rate is

    C =B log2(1+SNR) bits/s/Hz

    For MIMO the capacity is given by the following equation:

    Where M(or N) is the minimum number of transmitting antennas (NT) or

    number of receiving antennas (NR), M= min(NT , NR ).

    High Data rate Achieve

    Channel Capacity (C)

    Quality Minimize Probability of Error (Pe)

    Increase efficiency

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    C =M*B log2(1+SNR) bits/s/Hz

    &

    SNR= 10log10(Eb/N0)

  • MIMO CAPACITY

    With increase number of antennas the capacity of the system also increases.

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    2 4 6 8 10 12 14 16 18 200

    5

    10

    15

    20

    25

    SNR(dB)

    Cap

    acity

    (bi

    t/s/

    Hz)

    MIMO Capacity

    Shannon Capacity

    MIMO, NT=NR=1

    MIMO, NT=NR=2

    MIMO, NT=NR=3

    MIMO, NT=NR=4

    Cn=n*C1

  • BER PERFORMANCE OF A MIMO SYSTEM

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  • BER ANALYSIS OF BPSK MODULATOR

    Error Rate

    Calculation

    Tx

    Rx

    Error Rate

    Calculation

    0

    0Display

    Bernoulli

    Binary

    Bernoulli Binary

    Generator

    BPSK

    BPSK

    Modulator

    Baseband

    BPSK

    BPSK

    Demodulator

    Baseband

    AWGN

    AWGN

    Channel

    To generate random binary number(0 or 1) Bernoulli Binary Generator is used

    in Simulink Model.

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  • RESULT ANALYSIS OF BPSK USING MATLAB

    SIMULINKSL. NO. NAME OF PARAMETERS DESCRIPTION

    1. Channel Type AWGN

    2. Probability Error 0.5

    3. Initial seed 61

    4. Sample time 1

    5. Phase offset 0

    6. Signal to Noise Ratio 4.2 dB

    7. Input Signal Power 1

    8. Symbol Period 1

    9. Target no. of Error 100

    10. Maximum no. Symbols 1e6

    11 Modulation BPSK

    12 Error 0.076

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  • SINGLE CARRIER VS. MULTICARRIERS TRASMISSION

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    Multi-carrier ModulationMulti-carrier De-Modulation

    Multi-carrier modulations that use orthogonal waveform for modulating

    the sub-carriers are called

    orthogonal frequency division multiplex (OFDM) schemes.

  • ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING (OFDM)

    Since all the data on each of these

    subcarriers are transmitted

    simultaneously, =>'Multiplexing'.

    This spacing provides the orthogonality.

    Most popular solution for OFDM are

    Multi path, ICI & ISI by transmitting the

    Data parallel with longer period, Guard

    interval & Cyclic prefix.

    Alternate solution: Multi-carrierModulation (MCM) where channel isbroken up into sub bands or subcarriersuch that the fading over each sub channelbecomes flat thus eliminating the problemof ISI.

    Multi carrier modulation=> FDMA & OFDM

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    OFDM is a technology that we split a wide frequency band into many small

    frequencies and carry data onto each of these sub carriers. This is the meaning

    of 'Frequency Division'.

  • HOW OFDM WORKS

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  • OFDM MATHEMATICS

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  • MIMO-OFDM SYSTEM MODEL

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  • OFDM IN CELLULAR SYSTEMOFDM extends directly to MIMO channels with the IFFT/FFT and CP

    operations being performed at each of the transmit and receive antennas.

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  • MODULATION AND MAPPING

    BPSK-Modulation 16-QAM

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  • SERIES AND PARALLEL CONCEPTIn OFDM system design, the series and parallel converter to realize the

    concept of parallel data transmission.

    It solves the Multipath Fading in the channel

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  • PILOT INSERTIONS/SUBCARRIERS

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    It is a single frequency, transmitted over communication system for

    supervisory, control, synchronization the signal and help to carry the signal

    towards IFFT/IDFT in faster. It is inserted in Subcarrier of OFDM signals.

  • INTERFERENCES

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    ICI means that the orthogonality

    between different subchannels

    or Sub-carriers in the OFDM

    signal is destroyed/ lossed.

    ISI causes the loss of

    Orthogonality.

    It is avoided by using Cuclic

    Extension in the OFDM signals.

    ICI Caused by Delay spread >

    guard interval or CP

    Solution; CP> Path delay spread

    ISI is induced in a signal when itpasses through a frequency-selective Channel .

    It is avoided by using Guardinterval (Tg)

    By assuming the same data rate:

    For Single-carrier

    Bs > Bc => interference, ISI

    (Frequency selective fading)

    Multicarrier

    Bs < Bc => No interference (Flat fading)

    Inter-Carrier Interference (ICI) Inter-Symbol Interferenc