نتایج جستجو برای: reduction division
تعداد نتایج: 582723 فیلتر نتایج به سال:
This study evaluated the effectiveness of early orthodontic treatment with the Twin-block appliance for the developing Class II Division 1 malocclusion. This multicenter trial was carried out in the United Kingdom. A total of 174 children, aged 8 to 10 years old, with Class II Division 1 malocclusion were randomly allocated to receive treatment with a Twin-block appliance or to an untreated, co...
The dialogical self-theory knows the human's mind as an internal society that its members (the types of self) are engaged in dialogue and dominance seeking as well as an external society. This theory has divided the "self" into three types: traditional (mythical), modern, and post-modern, and then mentioned the characteristics of each according to historical epoch linked with them. Pr...
High Peak-to-Average Power Ratio (PAPR) is the one of the major drawback of the Orthogonal Frequency Division Multiplexing (OFDM) transmitted signal. Thus, a high-dynamic range amplifier is needed, which increases the cost of the system. In this paper, a new PAPR reduction technique using new phase sequence based on some existing scheme is proposed to reduce the high Peak-to-Average Power Ratio...
Orthogonal frequency division multiplexing (OFDM) modulation using orthogonal subcarriers reduces the delay spread by increasing robustness to multipath fading and can use overlapped bandwidth due to orthogonality on frequency domain. The main drawback of Orthogonal Frequency Division Multiplexing(OFDM) systems is the high peak-to average power ratio (PAPR),which significantly reduces the effic...
High peak-to-average power ratio (PAPR) of the transmitted signal is one of the limitations to employing orthogonal frequency division multiplexing (OFDM) system. This paper considers the use of the tone injection (TI) scheme to reduce the PAPR of an OFDM signal. However, optimal TI (OTI) requires an exhaustive search over all combinations of possible constellations, which is an NP-hard problem...
In several wireless communication systems and standards, Orthogonal Frequency Division Multiplexing (OFDM) is used widely due to its high spectral efficiency, high data rate, multipath delay spread tolerance, power efficiency, robustness to multipath fading channels and immunity to the frequency selective fading channels. However, the main challenge for OFDM system implementation is high PAPR, ...
Partial Transmit Sequence (PTS) is a promising technique to reduce Peak-to-average power ratio (PAPR) of orthogonal frequency division multiplexing (OFDM) signals. However optimum PTS (OPTS) needs exhaustive search over all combinations of allowed phase weighting factors. It results in high computational complexity. Grouping Phase Weighting (GPW) technique is a method which has reduced computat...
A major obstacle in realizing fast packet switching in all-optical networks is the large tuning delays of tunable optical devices. This paper proposes a multiaccess scheme for all-optical local area networks which employs both wavelength and code concurrency. In this scheme, several users share a wavelength channel through code multiplexing. The delay performance of hybrid wavelength/code divis...
New generation wireless systems target to support much higher data rate which requires larger bandwidth than the existing systems. Lack of contiguous spectrum resources and the compatibility requirement with the legacy systems make the concept of carrier aggregation (CA) a practical means for supporting high data rate in next generation systems. One of the practical issues related to the CA is ...
A number of researches have indicated a gradual increase in mean temperature throughout the world. Yet, there are some reports on the reduction of annual mean temperature. In this research we investigated a long-term trend of annual mean temperature in 34 synoptic stations in Iran (2 stations in cold and humid climates 14 in humid and moderate climates, 11 in Steppe climate and 7 in desert clim...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید