International Journal of Engineering and Technical Research (IJETR)
ISSN: 2321-0869 (O) 2454-4698 (P) Volume-7, Issue-7, July 2017
Advanced Filter-Bank Multicarrier System for QAM
Signal Transmission and Reception
Udit Nigam, Mr. Pratyush Tripathi
FBMC framework without the characteristic obstruction.
Additionally, we recommend the orthogonality conditions for
a FBMC-QAM without the characteristic obstruction. With a
specific end goal to fulfill the recommended orthogonality
conditions, the proposed FBMC-QAM framework performs a
sort of square interleaving for the odd-numbered
sub-transporter images after the model separating. The
proposed FBMC-QAM framework has an enhanced ghastly
productivity against the ordinary OFDM framework with CP,
at the very least the measure of the CP size. Besides, the
traditional MIMO transmission plans, for example, MLD and
Alamouti STBC, can be used with the proposed FBMC-QAM
framework. Additionally, the customary channel estimation
plans utilized for OFDM framework can be connected to the
proposed FBMC-QAM framework comparatively as in
OFDM.
Abstract— Due to its various points of interest, orthogonal
recurrence division multiplexing (OFDM) has been the
broadband remote access innovation of decision for some remote
guidelines in the course of the most recent decade. As of late,
channel bank based multicarrier systems are rising as one of the
distinct options for OFDM for cutting edge broadband remote
access systems. In request to fulfill the recommended
orthogonality conditions, we perform a sort of piece interleaving
for the odd-numbered sub-bearer sifting. The beneficiary
structure is the partner to the transmitter. Numerical results
appeared that the proposed FBMC-QAM framework has just
about the same piece mistake rate (BER) execution contrasted
with the FBMC-OQAM what's more, the orthogonal recurrence
division multiplexing (OFDM) framework. with the proposed
FBMC-QAM, numerous information multiple output
transmission plans and channel estimation plans can be used
likewise as in OFDM.
Index Terms— Filter-Bank Multicarrier (FBMC), Bit Error
Rate (BER), FBMC/OQAM, Multicarrier.
I. INTRODUCTION
The OFDM is the balance plan having multi transporter
transmission methods here the accessible range is separated
into numerous transporters every one being tweaked at a low
rate information stream. The dividing between the
transporters is nearer and the bearers are orthogonal to each
other avoiding impedances between the firmly dispersed
bearers henceforth OFDM can be considered as a blend of
balance and multiplexing systems, every bearer in a OFDM
signal has exceptionally contract data transmission so the
subsequent image rate is low which implies that the sign has
high resilience to multi way postpone spread lessening the
likelihood of bury image obstruction (ISI)which is the
prerequisite throughout today's correspondence systems.
spectrum instigate lost the ghastly effectiveness. Channel
bank-based multicarrier/counterbalance quadrature adequacy
adjustment (FBMC/OQAM) regulations are potential
promising possibility for cutting edge frameworks
and also 5G frameworks .Undoubtedly, the great recurrence
confinement of the model channels utilized in FBMC/OQAM
offers to this last the power to a few weaknesses, for example,
the timing misalignment between clients .In this paper, we
propose a FBMC-QAM framework with two model channels
for transmitting QAM signals without the CP, without BER
execution corruption. One model channel is utilized for the
even-numbered sub-transporter images and the other model
channel is utilized for the odd-numbered sub-transporter
images. This different sifting makes it conceivable to have the
Udit Nigam, Department of Electronics & Communication Engineering,
M.Tech Scholar, Kanpur Institute of Technology, Kanpur, India.
Mr. Pratyush Tripathi, Associate Professor, Department of Electronics
& Communication Engineering, Kanpur Institute of Technology, Kanpur,
India.
Figure 1 Transmitter and receiver block diagram in PFDM
and FBMC
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Advanced Filter-Bank Multicarrier System for QAM Signal Transmission and Reception
As fig.1 shows transmitter/collector block diagram of OFDM
and FBMC are fundamentally the same to each other. At the
transmitter, inverse fast Fourier transformation (IFFT)
operation is trailed by CP insertion in OFDM (to battle with
ISI), while it is trailed by a PPN in FBMC. In the same way,
CP removal is substituted with PPN in FBMC to separate the
data images at the beneficiary. A few other improvements in
the course of the most recent two decades have shown low
intricacy and productive executions of FBMC, clearing the
route for its thought in the cutting edge remote guidelines.
II. ORTHOGONAL RECURRENCE DIVISION MULTIPLEXING
(OFDM)
A. OFDM
In OFDM system, bits are mapped to constellation symbols
where the modulation and demodulation are, respectively,
insured by the inverse fast Fourier transform (IFFT) and the
fast Fourier transform (FFT). The time domain of an OFDM
symbol calculated with N IFFT point is given by
Figure 2 complete OFDM systems
Where,
N is the number of subcarriers,
T is the OFDM symbol period,
Cm,n is a complex-valued symbol transmitted on the
mth subcarrier and at the instant nT, and
f (t) is a rectangular time window, defined by
B. ORTHOGONALITY
The key to OFDM is maintaining orthogonality of the
carriers. If the integral of the product of two signals is zero
over a time period, then these two signals are said to be
orthogonal to each other. Two sinusoids with frequencies that
are integer multiples of a common frequency can satisfy this
criterion. Therefore, orthogonality is defined by:
Considering high values of N and according to the central
limit theorem, the IFFT block transforms a set of independent
complex random variables to a set of complex Gaussian
random ones. In a distortion-free noiseless channel, the
received symbol is given by the following equation-
where n and m are two unequal integers; f0 is the fundamental
frequency; T is the period over which the integration is taken.
For OFDM, T is one symbol period and f0 set to 1/T. for
optimal effectiveness.
Where, Cmn is the received symbol,
(a)
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International Journal of Engineering and Technical Research (IJETR)
ISSN: 2321-0869 (O) 2454-4698 (P) Volume-7, Issue-7, July 2017
far as OFDM, the bits inside of an OFDM image are modified
in such a design so that adjoining bits are set on non-nearby
subcarriers. To the extent De-Interleaving is concerned, it
again revises the bits into unique structure amid gathering.
G. CONSTELLATION MAPPER/DEMAPPER
The Constellation Mapper basically maps the incoming
(interleaved) bits onto different sub-carriers. Different
modulation techniques can be employed (such as
QPSK,BPSK, QAM etc.) for different sub-carriers. The
De-Mapper simply extracts bits from the modulated symbols
at the receiver.
H. INVERSE FFT/FFT
This is the most important block in the OFDM
communication system. It is IFFT that basically gives OFDM
its orthogonality. The IFFT transform a spectrum (amplitude
and phase of each component) into a time domain signal. It
converts a number of complex data points into the same
number of points in time domain. Similarly,FFT at the
receiver side performs the reverse task i.e. conversion from
time domain back to frequency domain.
(b)
Figure 3 (a) Shows the spectrum of each carrier
(b) Shows the overlap combine response.
C. SCRAMBLR/DESCRAMBLE
Information bits are given to the transmitter as inputs. These
bits go through a scrambler that randomizes the bit
arrangement. This is done with a specific end goal to make the
info arrangement more scatter so that the reliance of
information sign's energy range on the genuine transmitted
information can be dispensed with. At the collector end
descrambling is the last step. Descrambler just recuperates
unique information bits from the mixed bits.
III. ADDITION/REMOVAL OF CYCLIC PREFIX
Interleaving is done to shield the information from burst
mistakes amid transmission. Reasonably, the in-coming piece
stream is re-masterminded so that neighboring bits are not any
more adjoining each other. The information is broken into
pieces and the bits inside of a piece are improved. Talking as
far as OFDM,the bits inside of an OFDM image are modified
in such a design so that adjoining bits are set on non-nearby
subcarriers. To the extent De-Interleaving is concerned, it
again revises the bits into unique structure amid gathering.
D. ENCODER/DECODER
The mixed bits are then encouraged to the Reed Solomon
Encoder which is a part of Forward Error Correction (FEC).
Reed Solomon coding is a blunder revision coding method.
Info information is over-inspected and equality images are
figured which are then attached with unique information .
long these lines repetitive bits are added to the genuine
message which gives resistance against serious channel
conditions. A Reed Solomon code is spoken to in the structure
RS (n, k), where,
IV. FILTER BANK MULTICARRIER (FBMC)
Channel bank multi-transporter (FBMC) regulations, and all
the more particularly FBMC-Offset quadrature amplitude
modulation (OQAM), are seen as an intriguing option to
OFDM for future remote correspondence frameworks . The
time/recurrence determination of the waveforms is expanded
and can be exchanged off bringing about a superior use of the
physical assets and possibly in an enhanced strength to
time-variation channel attributes also, bearer recurrence
balances. Like OFDM, FBMC-OQAM disintegrates the
correspondence
channel
in an
arrangement
of
lower-transmission capacity sub channels that can hence
additionally be remunerated at a low unpredictability with a
single-tap equalizer. As opposed to OFDM, FBMC-OQAM
does not require the expansion of a cyclic prefix and the made
subchannels are just roughly level and orthogonal. At the
point when the channel recurrence selectivity expands, the
FBMC-OQAM framework experiences both between
subchannel obstruction and between image impedance on
each subchannel, making it important to utilize propelled
equalizer structures . Moreover the blend of FBMC-OQAM
with SIMO techniques results in an unmanageable impedance
term showing up between the reception apparatus streams on
neighboring subchannels, that makes the outline of the
framework testing. The configuration of SIMO
FBMC-OQAM frameworks has set off a great deal of
exploration as of late.
(1)
(2)
Here m is the number of bits per symbol, k is the number of
input data symbols (to be encoded), n is the total number of
symbols (data + parity) in the RS codeword and t is the
maximum number of data symbols that can be corrected. At
the receiver Reed Solomon coded symbols are decoded by
removing parity symbols.
E. CONVOLUTION ENCODER/DECODER
Error-coded bits are further coded by Convolutional encoder.
This coder adds redundant bits as well. In this type of coding
technique each m bit symbol is transformed into an n bit
symbol; m/n is known as the code rate. This transformation of
m bit symbol into n bit symbol depends upon the last k data
symbols, therefore k is known as the constraint length of the
Convolutional code.
F. INTERLEAVER / DE-INTERLEAVER
Interleaving is done to shield the information from burst
mistakes amid transmission. Reasonably, the in-coming piece
stream is re-masterminded so that neighboring bits are not any
more adjoining each other. The information is broken into
pieces and the bits inside of a piece are improved. Talking as
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Advanced Filter-Bank Multicarrier System for QAM Signal Transmission and Reception
As we are concerned about peb, which depends on SNRr,
maximizing SNRr after detection, leads to minimize the peb.
It is well known that the maximum SNRr value after detection
is achieved thanks to the matched filter:
Then peb is given by:
Where,
Assuming that jhi1j are zero-mean i.i.d. Rayleigh random
variables with variances equal to one, the distribution of khk2
is chi-squared with 2Nr degrees of freedom, expected value of
Nr, and variance equals to 2Nr.
Figure 4 OQAM modulation and synthesis filter bank.
VI. RESULTS
BIT ERROR RATE
One of the changes that modern digital communications
systems have brought to radio engineering is the need for
end-to-end performance measurements. The measure of that
performance is usually bit-error rate (BER), which quantifies
the reliability of the entire radio system from ―”bits in” to
“bits out” including the electronics, antennas and signal path
in between.
On the surface, BER is a simple concept— its definition is
simply:
Figure 5 OQAM demodulation and analysis filter bank.
BER = Errors/Total Number of Bits
With a strong signal and an unperturbed signal path, this
number so small as to be insignificant. It becomes significant
when we wish to maintain a sufficient signal-to-noise ratio in
the presence of imperfect transmission through electronic
circuitry (amplifiers, filters, mixers, and digital/analog
converters) and the propagation medium (e.g. the radio path
or optical fiber).
V. SIMO SYSTEM
Let us assume that we have at the receiver side Nr antennas
and a single transmit antenna.
This communication format is often described as Single-input
Multiple-Output (SIMO). Fig.
3.6 gives its representation. If we regroup the received
samples from the different receive antennas in a column
vector:
r=hs+n
The simulation results obtained for BER implementation
using the OFDM, FBMC and FBMC-OQAM technique. The
system parameters for comparative simulations are listed in
Table 1.
where h = [h11 h21 ::: hNr-1]T is an Nr *1 vector
Table 1 Simulation Parameters
Simulation Parameters
Number
of
OFDM
symbols
Number of subcarriers
Overlapping Factor
Complex modulation
CP size for OFDM
Specifications
1000000
2048
K = 2, 3, 4
QPSK
48
The following graph shows the Bit Error Rate (BER)
performance for OFDM, FBMC-OQAM & proposed
FBMC-QAM using AWGN channel and proposed method is
better.
Figure 6 SIMO representation model.
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International Journal of Engineering and Technical Research (IJETR)
ISSN: 2321-0869 (O) 2454-4698 (P) Volume-7, Issue-7, July 2017
Figure 7 The BER performance of OFDM, FBMC-OQAM &
proposed FBMC-QAM for AWGN channel
Figure 9 The Frequency response of Prototype Filter for
FBMC
The following graph shows the Bit Error Rate (BER)
performance for OFDM, FBMC-OQAM & proposed
FBMC-QAM using Fading channel and proposed method is
better.
The following figure shows the power spectrum of FBMC
method with Prototype Filter K = 4. It explains about the less
power consumption of FMBC techniques than OFDM.
Figure 8 The BER performance of OFDM, FBMC-OQAM &
proposed FBMC-QAM for fading channel
Figure 10 The power spectrum graph for FBMC
The following figure shows the power spectrum of OFDM
method with Prototype Filter K = 4.
The following graph shows frequency response of prototype
filter for FBMC.
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Advanced Filter-Bank Multicarrier System for QAM Signal Transmission and Reception
[5] A. Sahin, I. Guvenc, and H. Arslan, ―A Survey on Prototype Filter
Design for Filter Bank Based Multicarrier Communications,‖ Online:
http://arxiv.org/pdf/1212.3374.pdf.
[6] R. Zakaria, D. Le Ruyet and M. Bellanger, ―Maximum likelihood
detection in spatial multiplexing with FBMC,‖ in Proc. 2010 European
Wireless Conf., pp. 1038-1041, April. 2010.
[7] M. Renfors, ―FBMC and the Alamouti scheme,‖ in proc. of European
Wireless conference (EW 2010), Lucca, Italy., pp. 12-15, April. 2010.
[8] C. Lele, ―Iterative scattered-based channel estimation method for
OFDM/OQAM,‖ in EURASIP Journal on Advances in Signal
Processing., 42, 2012.
[9] C. LTlT, P. Siohan and R. Legouable ―Channel estimation with
scattered pilots in OFDM/OQAM,‖ in in SPAWC 2008, Recife, Brazil.,
pp. 286-290, Jun. 2008.
[10] R. Zakaria and D. Le Ruyet, ―On maximum likelihood MIMO
detection in QAM-FBMC systems,‖ in Proc. IEEE 21st Int. Symp. Pers.
Indoor and Mobile Radio Commun. (PIMRC)., pp. 183-187, Sep. 2010.
[11] R. Zakaria and D. Le Ruyet, ―A novel filter-bank multicarrier scheme
to mitigate the intrinsic interference: Application to MIMO systems,‖
IEEE Trans. Wireless Commun., pp. 1112-1123, Mar. 2012.
Udit Nigam, M.Tech Scholar,
Department of Electronics &
Communication Engineering, Kanpur Institute of Technology, Kanpur,
India.
Mr. Pratyush Tripathi, Associate Professor, Department of Electronics
& Communication Engineering, Kanpur Institute of Technology, Kanpur,
India.
Figure 11 The power spectrum graph for OFDM
In Figure 10 and Figure 11 the performance of power
consumption and shows that FBMC technique consumes less
power than OFDM technique.
VII. CONCLUSION
This paper proposed the FBMC-QAM framework which can
transmit the QAM images through the different sifting for the
even-numbered
sub-transporter
images
and
the
odd-numbered sub-transporter images. Likewise, the
orthogonality conditions for the FBMC-QAM framework
without the characteristic impedance was proposed. To fulfill
the orthogonality conditions, we perform a sort of square
interleaving system for the odd-numbered sub-transporter
images after the sifting. Our numerical results demonstrate
that the BER exhibitions of the proposed FBMCQAM are
nearly the same as those of the traditional OFDM also,
FBMC-OQAM frameworks. Additionally, the proposed
FBMC-QAM framework has an enhanced phantom
productivity since the proposed FBMC-QAM framework
don't require the CP. Moreover, SIMO transmission plans can
be used with the proposed FBMC-QAM framework.
Additionally, the traditional channel estimation plans utilized
for OFDM framework can be connected to the proposed
FBMC-QAM framework comparably as in OFDM.
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and
Modulation,
3GPP
Std.
TS
36.211.
[Online].Available:http://www.3gpp.org/ftp/pecs/html-info
/36211.htm
[2] P. Siohan, C. Siclet, and N. Lacaille, ―Analysis and design of
OFDM/OQAM systems based on filterbank theory,‖ IEEE Trans. Signal
Process., vol. 50, no. 5, pp. 1170-1183, May. 2002.
[3] M. Bellanger, ―Specification and design of a prototype filter for filter
bank based multicarrier transmission,‖ in Proc. IEEE Int. Conf.
Acoustics, Speech, and Signal Processing., vol. 4, pp. 2417-2420, May.
2001.
[4] B. Farhang-Boroujeny, ―OFDM versus filter bank multicarrier,‖ IEEE
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