File Name: difference between lte and lte advanced .zip
LTE represents a radical new step forward for the wireless industry, targeting order-of-magnitude increases in bit rates with respect to its predecessors by means of wider bandwidths and improved spectral efficiency. Beyond the improvement in bit rates, LTE aims to provide a highly efficient, low-latency, packet-optimized radio access technology offering enhanced spectrum flexibility. The LTE design presents radical differences at every layer.
This paper offers an introduction to the mobile communication standard known as LTE Advanced, depicting the evolution of the standard from its roots and discussing several important technologies that help it evolve to accomplishing the IMT-Advanced requirements.
A short history of the LTE standard is offered, along with a discussion of its standards and performance. LTE-Advanced details include brief history of the standard, technical requirements, as well as analysis on the physical layer, resource control, and performance.
However, LTE Advanced is capable of peak download data rates of 1 Gbps, with a wide transmission bandwidth, low C-plane latency, backwards compatibility, increased user throughput and spectrum flexibility. In 4G, it is estimated that MHz bandwidths will offer data rates of 1 Gbps and while OFDM offers an easy way to increase bandwidth by adding additional subcarriers, the scheduler would have to include a mix of terminals.
The 3GPP working groups looking at proposals for the standard have focused mainly on the physical layer; the topics analyzed included relay nodes, scalable system bandwidth exceeding 20 MHz, local area optimization of air interface, flexible spectrum usage, diversity MIMO, etc.
Ultimately, standardization is expected to be included in 3GPP Release 10 timeframe. Major enhancements to LTE were introduced in Release 10 after a correction and improvement phase in Release 9. By , all LTE features related to its functionality were finished and by , most protocol and performance specifications were finished and included in Release 8. Here are several LTE design parameters [ Martin09 ]:.
In order to achieve these goals, LTE made use of a new system architecture combined with enhanced radio access technology. It divided network functions such as modulation, header compression and handover to the radio access network, while others such as charging, mobility management to the core network. In this section, several concepts related to radio access network are discussed in order to offer better understanding of the technology behind LTE.
The most important requirements are the following [ Martin09 ]:. The physical layer implements OFDMA scheme on the downlink for high spectral efficiency, robustness against frequency-selectivity and multi-path interference.
It supports flexible bandwidth deployment, facilitates frequency-domain scheduling and is well suited for MIMO techniques. This implies a common structure of transmission resources compared to the downlink. The addition of the cyclic prefix supports frequency-domain equalization on the transmission. The transmission resource structure basic unit is the physical resource block PRB.
There are 12 subcarriers allocated for 0. The following points present some of the design features of the downlink and uplink implementation. The performance of systems such as LTE is already close to the Shannon limit. Several approaches have been discussed in [ Parkvall09 ] that would improve SNR values. Wider-band transmission and spectrum sharing would meet the high-peak data rate requirement; however, in order to be backwards compatible, spectrum compatibility can be achieved through multiple LTE carrier components.
Carrier aggregation is illustrated in Figure 1. Another implementation that would improve data rate is the use of multiple antennas. Technologies such as beam-forming and spatial multiplexing are already incorporated in LTE and are expected to be developed further in LTE-Advanced. Coordinated multi-point CoMP transmission is another method of improving system performance.
In the downlink, it involves coordination of the transmissions from multiple transmission points depending on how much terminals are aware of transmissions originating from multiple points. Yet another solution would be the inclusion of relays and repeaters on the network node path; thus, the long distances among nodes are eliminated, allowing for higher data rates. Several simple system tests have been carried out in [ Parkvall09 ]; a CoMP system is simulated; some of the assumptions are listed in table 1 attached , which are similar to 3GPP simulation case 1 in [ 3GPPc ].
It is seen that the CoMP system yields significant performance gains. As expected the gain is larger for the system with more coordinated cells. The loss due to using erroneous channel values at the transmitter is evident, but a majority of the gain remains. It is seen that the CoMP system yields significant performance gains, and the gains are larger for the system with more coordinated cells. Recall that the transmitted signals in uplink CoMP are generated independently of the channel realizations; hence, from a coordination perspective there is no need to consider channel estimation errors at the transmitter for the uplink.
These results are indeed very promising. Note however that several ideal assumption have been made that are challenging to solve, foremost including feedback of estimates of downlink channels encoding and transmitting with low latency. Theory, , 21 5. Back to Table of Contents. Traian Andrei , ta8 cec. Raj Jain.
To move to higher-speed networks that can cater to customer demand for mobile broadband multimedia applications, the 3GPP has developed the latest LTE-Advanced LTE Release 10 standard, which will be fixed in December This book focuses on LTE and LTE-Advanced, and provides engineers with real insight and understanding into the why and how of the standard and its related technologies. This book is written by engineers from Ericsson--the world's leading telecommunications supplier--who was heavily involved in the development of the standard. Erik Dahlman works at Ericsson Research and are deeply involved in 4G and 5G development and standardization since the early days of 3G research. Stefan Parkvall works at Ericsson Research and are deeply involved in 4G and 5G development and standardization since the early days of 3G research. Johan Skold works at Ericsson Research and are deeply involved in 4G and 5G development and standardization since the early days of 3G research. We are always looking for ways to improve customer experience on Elsevier.
This ongoing race of increasing sequence numbers of mobile system generations is in fact just a matter of labels. What is essential is the actual system capabilities and how they have advanced. The evolution of 3G systems into 4G is powered by the creation and growth of new services for mobile devices, and is enabled by advancement of the technology available for mobile systems. There has also been an evolution of the environment in which mobile systems are deployed and operated, in terms of levels of competition between mobile operators, challenges from other mobile technologies, and new regulation of spectrum use and market aspects of mobile systems. Fixed telephony POTS and earlier generations of mobile technology were developed for circuit switched services, primarily voice. This also affected the first development of 3G,which was primarily based on circuit switched data, with packet-switched services as an add-on. IP is in itself service agnostic and thereby enables a range of services with different requirements.
This paper offers an introduction to the mobile communication standard known as LTE Advanced, depicting the evolution of the standard from its roots and discussing several important technologies that help it evolve to accomplishing the IMT-Advanced requirements. A short history of the LTE standard is offered, along with a discussion of its standards and performance. LTE-Advanced details include brief history of the standard, technical requirements, as well as analysis on the physical layer, resource control, and performance.
Мгновение спустя, словно в дешевом фильме ужасов, свет в ванной начал медленно гаснуть. Затем ярко вспыхнул и выключился. Сьюзан Флетчер оказалась в полной темноте. Сьюзан Флетчер нетерпеливо мерила шагами туалетную комнату шифровалки и медленно считала от одного до пятидесяти. Голова у нее раскалывалась. Еще немного, - повторяла она мысленно. - Северная Дакота - это Хейл.
Хейл внезапно почувствовал беспокойство - скорее всего из-за необычного поведения Сьюзан.
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