Tag: mimo

The MIMO antenna technology in LTE

In LTE wireless networks, MIMO antenna technology is used. MIMO stands for Multiple Input / Multiple Output.

 

Instead of a sending and receiving antenna, in the MIMO technology, up to four transmitter antennas and four receiver antennas to be used. The corresponding codes are 4×4 four transmitting and receiving antennas, or 2×2 for two transmitting and receiving antennas. MIMO enables simultaneous transmitting multiple data streams on the same frequency. Systems with a single antenna are called SISO (Single Input / Single Output).

In principle, the multiple-antenna systems have the following advantages: First, you get a bigger reception power and thus greater range, secondly suppress interference from other radio waves better, make for a better connection quality thirdly and fourthly, for better transfer rates. However, one cannot utilize all four at the same time maximum benefits: You have to decide whether you want to improve the system in a data-transfer speed or the range or quality of the connection.

Key technology for LTE

MIMO is a key technology in LTE wireless networks, since they are the spectral efficiency is improved. However, MIMO is not only used on LTE, but also used in WiMAX and WLAN systems. By using multiple antennas, in LTE, the reception signal improved and interference can be reduced – that is, it results in less interference from other radio frequency used. But the most important: The MIMO technology is at the LTE transmission of the data stream to be distributed to up to four transmit and receive antennas. This increases the amount of data that is transferred per unit time, thus ensures a higher transmission speed – while reducing the error rate.

LTE can use up to four times four antennas, it provides for the 3GPP Release 8, which is defined in the technical specifications for LTE. Also two times two MIMO systems are possible. In a 2×2 MIMO, the data rate in comparison to a system can be doubled with a respective antenna almost.

Devices with MIMO antennas

A technical challenge may be the equipment of devices with multiple antennas – a smartphone offers relatively little room for a higher number of antennas. At low frequencies such as the 800-megahertz band, the problem is compounded by the fact that there are larger antennas needed. Especially in the countryside, however, LTE will use this frequency range. Installation of multiple antennas in laptops is problematic. Since the LTE stations will initially replace the missing country’s DSL, it imposes the use of MIMO technology is quite well possible.

 

Real 4G LTE Advanced Technology and the Future

Since November 2008, under the name IMT-Advanced, LTE and WiMAX are the specifications for the fourth generation of mobile. The International Telecommunication Union (International Telecommunication Union, ITU short) set these requirements.

 

Since October 2009, two technology families apply for the title of 4G wireless data technology of the future, according to the International Telecommunication Union. Firstly, there is the advanced technology LTE Advanced, which evolutes from LTE. Second, the applicant is provided with the bulky abbreviation IEEE 802.16m technology, which has evolved from the WiMAX group.

Colloquially LTE or Mobile WiMAX is already now referred to as 4G technologies. In colloquial usage, technical standards, there are 3G systems.

The ITU standards: A gigabit per second is the goal

Some key requirements on wireless technologies of the fourth generation: Higher transmission rates, greater bandwidth, high spectral efficiency and low latency and better coverage of the peripheral areas in the radio cells are crucial criteria.

As research targets for the transmission rate is at 100 megabits per second per the International Telecommunications Union, and gigabit per second high with low mobility. There are also up to 40 megahertz scalable bandwidth for the transmission channel, but the researchers are encouraged to draw bandwidths up to 100 MHz considered. The spectral efficiency is measured by measuring the transmission rate per bandwidth. The ITU for IMT-Advanced set 15 bits per second per hertz (bits/s/Hz) on the downlink and 6.75 bit / s / Hz in the uplink.

As examples of different high top speeds in different widths, radio channels are given by the ITU on a channel of 40 megahertz (MHz) 600 Mbit/s and on a channel of 100 Megahertz 1500 Mbit/s respectively in the downlink.

The 4G LTE-Advanced candidate

The bandwidth is LTE-Advanced is significantly higher than the 3G. Instead of 20 megahertz, LTE-Advanced can bundle multiple carriers and thus use up to 100 MHz simultaneously. It is also possible that frequency bands in different frequency ranges are combined, since no operator has been on a continuous frequency range of 100 MHz Currently these 100 MHz are only theoretically achievable, in practice more spectra has to be assigned. This can happen only in 2015 at the World Radio Conference (WRC). Until then, the bandwidth will probably be limited to 40MHz.

Another innovation that could keep up with LTE-Advanced collection is called “relay nodes”, i.e. relay stations. This will allow, even outside the range of a base station to receive the signal. In the edge region reinforce the signal relay stations. Connected the relay stations are connected to the base station. Thus, the signal strength inside buildings can be improved.

Increase the spectral efficiency

The concept of multiple antennas (MIMO: Multiple Input / Multiple Output) technology, which is already partially used, will also be expanded. Instead of two antennas at the transmitter and receiver (2×2 single-user MIMO) to be introduced up to eight antennas for the downlink (8×8 single-user MIMO). For upload, still four antennas are used. Simultaneously by using multiple antennas, a plurality of data streams on the same frequency is transmitted. This not only increases the spectral efficiency, but also the transmission quality.

When the spectral efficiency of LTE-Advanced will even peak values of up to 30 bits/s/Hz can be achieved in the download as well as 15 bits / s / Hz in the upload. LTE has the merit to 15 bits / s / Hz when receiving and at 3.75 bits / s / Hz when sending data. This shows that, although LTE in terms of spectral efficiency can already meet the requirements of IMT-Advanced, but only in the download. The upload, and in the range, it is far from being a 4G technology.

4G: colloquial and technical language

Although often LTE or Mobile WiMAX called 4G technologies, they are from the standpoint of technical standards only further developments in the field of 3G and provide an intermediate step represents some criteria for IMT-Advanced are indeed fulfilled to some extent, by no means all.

Nevertheless, the marketing departments of international mobile operators call the new LTE technology, which is increasingly used in the United States, even as 4G, to illustrate the difference in the speed of data transmission in comparison to UMTS networks. It is becoming apparent that this usage was soon penetrated. Then LTE or similar technology, such as Mobile WiMAX are commonly referred to as 4G technology, and only in the jargon of technical standards still out as 3G technologies.

 

LTE Technology

The new mobile technology LTE is superior to the existing mobile technologies GSM and UMTS, the link speed which data is transferred is much far higher the response time of the current system and the connection is faster.

 

This is achieved through a variety of improvements in various areas of technology that each contribute in itself to significantly better overall picture of the data radio technology. Due to the significant improvement in overall performance, LTE mobile technology is increasingly recognized as the 4th Generation (4G) refers. While in technical descriptions of the generation LTE 3.9 is assigned, but the name of LTE as 4G mobile technology is likely to prevail worldwide.

Improvements in wireless technology

A number of technical innovations allow use of the available radio room better. The OFDMA radio technology allows customizing the transmission capacity to meet the needs of each user – who wants to watch TV on the mobile Internet, gets more space than someone who just wants to make calls only. The downlink OFDMA is used for the same transmission speed with a very small range of the radio room – it takes up less space for an equal amount of data transmitted. Also known as High Speed OFDM Packet Access (HSOPA) technology uses the existing radio room two to four times better than the method called Wideband Code Division Muliple Access (WCDMA), which is used in HSDPA.

With the multi-antenna MIMO technology can be transmitted simultaneously with the current standard of four antennas and received simultaneously – what the reception improves performance significantly. Moreover, a possible interference by neighboring radio waves, which prevents so-called interference significantly stronger.

All in all, the radio room with LTE is better used, because the signals from the multiple antenna technology at transmission and reception are separated in space, and because the size of the radio channels can be adjusted according to the user.

Improvement in network construction

There are also improvements in network construction. The networks as a whole should be fit. In the network architecture, the requisite leaner architecture makes first by the absence of an element – namely the mediator between the base station and core network noticeable. The significantly higher amount of data that can be processed thanks to improved techniques the radio part of the network, of course, lead to the fact that mobile operators must also provide the lines between the base station and core network for more capacity.

Overall, the whole network will be improved so that its response times are less than five thousandths of a second (milliseconds). After all, only at a very low response time (latency) of the network can be demanding services such as Mobile TV, video calls and mobile online games provide no problems.

The competition techniques: Ultra Mobile Broadband and Mobile Wimax

LTE is the view of IT expects to be the first mobile technology, which works worldwide as a general standard. Nevertheless, there were – from a technical viewpoint – two other data transmission technologies that were considered LTE competitors: Mobile WiMAX and Ultra Mobile Broadband are techniques that offer similar data transfer speeds as the mobile technology LTE.

Ultra Mobile Broadband was a technology that is used in the USA the third mobile communications standard Should develop a rapid generation CDMA2000 mobile fourth generation. Above all, the U.S. chip maker Qualcomm invested diligently in the development based on CDMA 2000, while the Swedish Ericsson continued to LTE as a new cell phone technology. Both technologies used very similar approaches. In November 2008, Qualcomm ended its funding of research and waved a UMB to LTE.

Mobile WiMAX can achieve with the use of LTE and multi-antenna MIMO method on a 10-megahertz radio channel transmission speeds of a total of 90 megabits per second. These are divided in 63 megabits per second for downloading data (downlink) and 28 Mbit/s for transmission (uplink). However, radio cells are in Mobile Wimax achieved with a diameter of one to four kilometers far smaller than the LTE radio cell in the 800 megahertz range – where the diameter is 20 kilometers.

For network design brings dramatic benefits for this difference. LTE takes much less Send master and base stations to build a nationwide network.

 

LTE in Release 10—Ten Faster than LTE

The 3rd Generation Partnership Project (3GPP) standardized wireless technology Long Term Evolution (LTE). 3GPP is a consortium of several institutes.

 

The project also defines standards for other mobile technologies such as HSPA. In Release 10, LTE advanced is outlined, 9 expansion of LTE in Release 8 and Release 10 was introduced in 2009 as a proposal and completed in 2011.

 

 

100 Megahertz needed

 

The first 4th generation wireless technology, LTE advanced theoretically reaches up to 1 gigabit per second (GB/S) for receiving data (download) and up to 500 megabit per second (Mbit/S) for sending data.

 

Just like LTE in Release 8 and 9 uses LTE advanced is a 16-fold quadrature amplitude modulation (QAM), a technology that allows more data to be transported on a wave.

 

In contrast to the previous technologies, LTE advanced 100 Megahertz is used to frequency bandwidth, which can be summarized from independent frequency bands. This is necessary, because no operator called integrated 100 MHz of LTE frequencies into his own. This frequency bandwidth is shared by eight independent antennas, which must be installed at the transmitter as at the receiver. This technology is referred to 8 x 8 MIMO (Multiple Input Multiple Output).

 

 

LTE – Up to 300 Mbit/s Per Second for Release 9

The 3rd Generation Partnership Project (3GPP) standardized wireless technology Long Term Evolution (LTE). 3GPP is a consortium of several institutes.

 

 

The project also defines standards for other mobile technologies such as HSPA. In December 2009, the Release 9 followed as the second standard, which contained LTE after the year before the release had 8 defines first LTE.

 

Four independent antennas

 

LTE Release 9 help you reach computationally up to 326.4 Mbit/s for receiving data (download) and up to 86.4 Mbit/s for sending data (upload).

 

Compared to 172.8Mbit/s download, which can be reached with Release 8, the theoretical speed was almost doubled. These Technologies make it more possible. As with Release 8, a 16-fold quadrature amplitude modulation (QAM) is used, a technology that enables more data to be carried on a shaft.

 

In addition, up to 20 MHz frequency bandwidth used. However, Release 9 is used in contrast to its predecessor up to four independent antennas at the transmitter as the receiver; the same send or receive data. This technology is called MIMO (Multiple Input Multiple Output).

LTE – Up to 172.6Mbit/s

The 3rd Generation Partnership Project (3GPP) standardized wireless technology Long Term Evolution (LTE). 3GPP is a consortium of several institutes.

 

The project also defines standards for other mobile technologies such as HSPA. In Release 8 of the 3GPP LTE in 2008 for the first time defined. Here, speed and technology used were committed.

 

Different Technologies for Increasing the Data Rate

 

With Release 8, the theoretical top speed with LTE on 172.8 Mbit/s when receiving data (download) and up to 57.6 Mbit/s is limited to send data.

 

 

The speeds are made possible by a number of technical parameters. First, a 16 fold quadrature amplitude modulation (QAM) is used, a technology that enables more data to be carried on a shaft.

 

By a plurality of antennas at both transmitters on the receiver side as the speed is increased in both directions as well. This technology is called MIMO (Multiple Input Multiple Output). On LTE Release 8, two independent antennas are used (2 x 2 MIMO). Essential for the increase in speed is also the frequency bandwidth of the connection. In this case, up to 20 MHz, in order to transmit data.

 

 

In reality, the network operators are indeed technology such as MIMO and QAM are available, but there is a lack of sufficient bandwidth. This is spread across multiple network operators, so that in practice 50 to 75Mbit/s are technically feasible in the download.

 

 

 

LTE Reception-Need Two MIMO antennas

For LTE, the data come from the air via radio. This is good if you sit in the park in the summer and with a laptop surfing. But the new redio technology subject to the laws of physicas.

The reception inside building tends to be worse than the outdoor reception. This is shown by a glance at the map of Vodafone for LTE availability. There is difference between areas where you can go with LTE inside buildings to the Internet (indoor) and areas where there is only outside of buildings receiving a sufficiently strong there (outdoor).

We give you a few tips on how to speed up your wireless data, no matter if you live in an area where Vodafone is available indoors or in some place where LTE is available out.

LTE inside buildings

Even those who LTE users within buildings, can do one or the other in order to improve the reception. Walls can generally weaken the reception of mobile signals, particularly buildings that has been processed in some way reinforced concrete, here are real killjoys.

Simply, the receiving device in a window on, preferably at a window, which lie in the direction of the nearest transmission LTE tower where in your area mobile phone masts are, you can see it. You can also ask your LTE vendors are radioed from which transmission tower from you.

LTE outside buildings

Is there only LTE outside of buildings, you do not surf, shivering in long winter nights in snow and ice: here to help you perhaps an outdoor antenna. Such antennas are in free trade to buy, offer as a complete solution with everything you need to connect. Thus it comes to be a double antenna cables and connectors. If you a great handy man, who always puts together everything yourself. For LTE, you need a pair of antennas or a dual-antenna for wireless technology, they sends and receives simultaneously.