I. robust resistance to multipath — without the problem

I.                  
Previous Work Done on LTE

2.1. Muhammad
Mokhlesur Rahman,
Shalima Binta Manir “Performance Analysis of Sc-FDMA and OFDMA in LTE Frame
Structure”
– This
paper conclude that PAPR characteristics of LTE Frame Structure Type (LTE FDD
& LTE TDD) of SC-FDMA and OFDMA. From the result we conclude that, LTE FDD
has better performance than LTE TDD. PAPR of SC-FDMA and OFDMA in LTE FDD
achieve lower values on average. We see that FDD has a continuous reduction of
BER (Bit Error Rate) and it minimizes the BER up to a certain values of SNRs.
Comparing the Performance analysis, we can conclude that LTE FDD is the better
option than in LTE TDD in uplink Transmission-SC-FDMA and downlink
Transmission-OFDMA, because of its higher efficiency due to low PAPR 9.

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2.2 Moray Rumney “3GPP LTE:
Introducing Single-Carrier FDMA” – This paper concludes that SC-FDMA means
“create a single-carrier waveform and shift it to
the desired part of the frequency domain.” After a careful consideration of the
characteristics of OFDMA and the new SC-FDMA, we can conclude that SC-FDMA
provides the advantages of OFDMA — especially robust resistance to multipath —
without the problem of high PAR. The use of SC-FDMA in LTE, however, is
restricted to the uplink because the increased time-domain processing would be
a considerable burden on the base station, which has to manage the dynamics of
multi-user transmission.

 

It
will be interesting to see if LTE — the latest of the three new OFDMA cellular
standards — has indeed identified a superior solution for the uplink or whether
the pure OFDMA used in WiMAX or the OFDMA/CDMA combination used in UMB prove to
be just as successful when all the factors are taken into account. Today, the
experts disagree so we will have to wait on the ultimate arbiter, time, before
we find out for sure 10.

 

2.3. Ixia “SC-FDMA Single Carrier FDMA in LTE” -SC-FDMA
offers similar performance and complexity as OFDM. However, the main advantage
of SC-FDMA is the low PAPR (peak-average-power ratio) of the transmit signal.
PAPR is defined as the ratio of the peak power to average power of the
transmit signal. As PAPR is a major concern at the user terminals, low
PAPR makes the SC-FDMA the preferred technology for the uplink
transmission. PAPR relates to the power amplifier efficiency at the transmitter,
and the maximum power efficiency is achieved when the amplifier operates at the
saturation point. Lower PAPR allows operation of the power amplifier close to
saturation resulting in higher efficiency. With higher PAPR signal, the
power amplifier operating point has to be backed off to lower the signal
distortion, and thereby lowering amplifier efficiency. As SC-FDMA modulated
signal can be improve PAPR 11.

 

2.4. Monika Sehrawat “Performance comparison between OFDMA and SC-FDMA” – This paper  conclude that BER is the key parameter
for indicating the system performance of any data link. In this paper we
analyzed that for different values of SNR, the BER increases for high order
modulation in both the multiple access techniques (OFDMA and SC-FDMA) used in
next generation system and hence it is easily affected by the noise. BER
Performance of SC-FDMA and OFDMA are very similar but a part of them SCFDMA
have good performance as compare to the OFDMA 12.

 

 

 

2.5. Ghassan A. Abed , Mahamod Ismail and Kasmiran Jumari “A
Realistic Model and Simulation Parameters of LTE-Advanced Networks”-  This paper provides the full details of the
layering, architecture, and the configurations of the traffic model for
LTE-Advanced networks. After explaining the development from LTE to
LTE-Advanced, the paper focused on the benefits and the key features of it and
illustrated how LTE Advanced will become the major cellular system for the
users in next decade. The architecture of E-UTRAN and EPC are specified in
details with the links interfacing between the different elements of the
network. The main contribution of this article is to present and configure the
traffic model of LTE-Advanced using NS-2 simulator. One of the new concepts add
to LTE-Advanced was the relaying node, where this technique add to the proposed
model to support the model and to give it more credibility. Then, the
simulation parameters also identified with all links parameters in sides of
bandwidth and propagation delay. Lastly, the proposed topology implemented with
an animation demonstration using SCTP/TCP protocols to monitor the traffics and
the expected loss in packets during simulation scenario. In fact, this paper
tried to provide an efficient model of LTE-Advanced to assist the researchers
to experiment the developed items of this network over different conditions and
situation such as improve the congestion control algorithm for the protocol
used or to derive new technique to minimize the handover among base stations1314.