Improving system performance in terms of data rate, latency, mobility and cost is the scope of Long Term Evolution (LTE) system. All IP architecture with distributed mobility management that have been implemented in LTE and the handover (HO) decision
is performed by the evolved base station (eNB). The ping-pong movement in LTE is one of the most crucial problems which reduce the performance of the HO. In this paper, the impact of ping-pong handover on inter eNB handover in LTE networks is investigated. The object of the present work is to provide a method for reducing the number of ping-pong HOs in intra E-UTRA networks. A novel HO algorithm, based on keeping the old path between the source eNB and SGW/MME during the ping-pong movement and delaying the completion HO part,
is presented. The ping-pong avoidance algorithm for intra E-UTRA can be a tool to reduce the number of ping-pong HOs and control the demands of the network resources. Analysis results -based on fuzzy logic technique- of the proposed algorithm showed that the
probability of ping-pong HO can be reduced efficiently as the difference between the received signal strength from the target and the source (SS(target-source)) and the timer value are higher than 3dB and 1.5 sec respectively.
This work aims to analyze the performance of Orthogonal Frequency Division
Multiplexing (OFDM) applied in the fourth generation mobile networks and WiFi. Fuzzy
logic technique is used in this study to analyze the problem of OFDM, taking into
consi
deration the modulation techniques applied in OFDM. Three input parameters in the
fuzzy logic system are mainly considered: signal-to-noise ratio, the modulation degree and
the number of sub-carriers. The output parameters are selected to be the bandwidth and bit
error rate. This requires an analytical study to determine the optimal values of the input
parameters used in this study. This means studying the membership of functions of each
input and output parameter using fuzzy logic.
This works aims to study the performance of the mobile system via studying the
effects of adaptive modulation technique on the data rate. Fuzzy logic technique is used as
a tool to analyze the data rate of the downlink connection depending on type
of
modulation, coverage quality and the distant between the receiver and the transmitter. For
parameters were considered as input parameters for the fuzzy logic system mainly are:
power of the station, quality of coverage, the type of modulation technique and the signal
to interface noise ratio. One parameter is used as an output of the fuzzy system which is
spectrum efficiency in bit per second per hertz. Analytical study to select the optimal data
rates for different modulation techniques will be considered. Additionally, studying the
input and output memberships of the data rate parameters using fuzzy logic will be
explained. Keywords: Data rate, downlink, signal to noise ratio, modulation type, Fuzzy
logic, spectrum efficiency.
