In the 30 years of mobile communication development, millimeter wave has always been a virgin wilderness, such as qualcomm, Ericsson, huawei, zte communications giants such as laboratory research on it continuously, nowadays the application of millimeter wave in life has been more and more, millimeter wave radar technology, 5 g has the figure of millimeter wave technology, for the role of millimeter wave and its advantages and disadvantages, how much do you know? Hurry up to learn together!

What is a, millimeter wave

Millimeter wave really is what things? In fact, we can clear through high school physics textbooks, its essence is a kind of high frequency electromagnetic wave, it is 1-10 mm wavelength of electromagnetic wave, is generally between 30 GHZ - 300 GHZ frequency electromagnetic wave, is 5 g communication used in one of the main frequency band,

Second, the advantages and disadvantages of millimeter wave (MMW)

1, the advantages of the millimeter wave:

1) the very wide bandwidth, generally think of millimeter wave frequency range of 26.5 ~ 300 GHz, bandwidth up to 273.5 GHz, more than 10 times the bandwidth of all from dc to microwave, even considering atmospheric absorption, transmission in atmosphere can only use the four main window, but the four window of total bandwidth of up to 135 GHz, also for the microwave band bandwidth of the sum of all of the following five times, with the use of all kinds of multiple access reuse technology can greatly improve channel capacity, suitable for high speed multimedia transmission business, the frequency resources nervous today is extremely attractive,

2) narrow beam, under the same size of antenna of millimeter wave beam is much more narrow than microwave beam, for example, a 12 cm antenna beam width in 9.4 GHz is 18 degrees, while 94 GHz beam width is only 1.8 degrees, so you can tell apart the small target in the more recent or more clearly the details of the observable,

3) high reliability, high frequency makes it very little interference, can resist the influence of rain weather, provide stable transmission channel; Compared with laser, the millimeter wave propagation is affected by the climate is much smaller, can think with all-weather properties,

4) good directivity, millimeter wave absorption by all kinds of suspended particles in the air is bigger, makes the transmission beam narrower and increases the difficulty of hacking, suitable for short distance point-to-point communication;

5) very short wavelength, the antenna size is small, easy to integrated large-scale antenna array in small space, compared with microwave and millimeter wave components of the size is smaller and therefore easier to millimeter-wave system miniaturization,

2, the disadvantage of millimeter wave:

1) propagation in the atmosphere attenuation,

2) devices require high machining accuracy,

We have already made clear in the beginning, part of the millimeter wave communication is 5 g, 5 g is one of the two main frequency of communication, it delivers more than 5 g network speed is very fast, even 5 g differentiating experience is an important part of,

Millimeter wave as the difficulty of the highest in 5 g technology, perhaps at the beginning of the 5 g is not valued, but lack of the millimeter wave 5 g, 5 g is no soul,

CodePudding user response:

Some doubt about millimeter wave here to answer them one by one, do you have any questions welcome comments and ha

Q: at present, the millimeter wave in domestic application scenarios have?


Answer: millimeter-wave application scenarios: eMBB WTTx, move back,


Q: operators choose frequency of what are the advantages and disadvantages? Able to speak the actual?


Answer: sub3G advantage coverage performance is good, shortcomings available resources, less c-band advantage resources, TDD faults has imbalance,


Q: why millimeter wave is TDD.


A: millimeter wave high bandwidth, for cost reasons, UE do not need to support the bandwidth is too big, FDD spectrum bandwidth requirements for mobile phone support is higher, and easier to apply TDD beam informs,


Q: sub covers 5 g 3 g and 4 g is the same?


Answer: sub3g 5 g and 4 g coverage is similar, because no matter what kind of technology, sub 3 g band is the same, the cover effect is the same,


Q: AAU power than RRU power?


Answer: the AAU power higher than RRU, currently 200 w, 240 w, 320 w,


TDD q: has decoupled all manufacturers support now? Or huawei support?


Decoupling agreement, TDD answer: has nothing to do with factory, now some manufacturer support, some manufacturer does not support,


Q: which is now the mainstream of 5 g band?


Answer: the current mainstream 5 G band is mobile 2.6 G, telecom and China unicom Shared 3.4 3.6 G,