"5G Breakthrough Technology" New Lambert Lens Antenna?

1. lens antenna is a radial basis function (RBF) technology, similar to phased array antenna. If it is used as single-user beamforming (SUBF), it can be used to improve coverage, and if it is used as multi-user beamforming (MUBF), it can be equivalent to cell splitting. RBF is not directly related to 5G, and Lombard lens antenna has been applied in 4G LTE era.

2. Generally, digital beamforming (DBF) is the mainstream in order to control the beamforming direction and the interference between users more flexibly, but the antenna freedom of DBF is too high, which requires a lot of baseband computing resources. Therefore, regardless of LTE or 5G, the small bandwidth and high value spectrum scenario (Sub-6G) will only adopt DBF.

3. In order to reduce the consumption of computing resources and use a certain degree of antenna freedom, DBF and radial basis function are usually combined, that is, hybrid beamforming (HBF). At present, the 5 mm band adopts HBF.

In fact, lens antenna is an old theory, and there are already products abroad. But it is said that only two foreign manufacturers in the world have made antennas (not American yet). And super, super expensive. Because of the patent, because it needs manual fine operation. Some posts have already mentioned it. A small error can make a big difference in performance.

The principle of phased array beam discrimination is to subtract the signals of adjacent beams from the original signal. Here comes the problem. How do I know whether the adjacent channel sends 1 or 0? From the perspective of information theory, unknown bits are informative. If you have low reliability about whether the signal you receive is 0 or 1, then the adjacent beam will refer to your demodulation result to eliminate the interference of your beam, and the reliability will be low. Therefore, in order to reduce the bit error rate, a large number of auxiliary symbols need to be added to the air interface (not only the reference signal, but also the channel coding is sacrificed). This means that the amount of information per symbol is reduced.

If the isolation between adjacent beams can be improved physically, not only the amount of calculation will be greatly reduced, but most importantly, there is no need to do coherent operation, and auxiliary symbols will be sent between beams with sufficient isolation. The information content of each symbol has also been improved.

Therefore, ultra-narrow beam forming technology has always been the dream of smart antenna, and lensed antenna technology has been put into practical use.

Theoretically, this is a convex lens for centimeter waves and electromagnetic waves. Two advantages stand out:

1. Use fewer oscillators to achieve high gain. The principle of lens focusing is not repeated.

2. Excellent sidelobe suppression. Theoretically, the interference to adjacent lobes is better than that of phased array 10dB or more. (Don't mind the soul painter)

At present, compared with 4g, 5g has racked its brains in the protocol, and the performance per bit Hz is too slow. Masive mimo theory, 128 oscillator can only distinguish 32 beams. At present, the theoretical upper limit can only be 16 beam under the product calculation ability and process accuracy. It is even worse on the existing network, which is actually three times higher than the dual-channel antenna. The reason is that the coherence index between beams is not excellent enough.

If the lens antenna can achieve the theoretical goal, adjacent beam multiplexing should be feasible, and RB multiplexing for every other beam is definitely no problem, so it is easy to raise the level of eight beams by four times. If it's 8*8. Then 16 times is also very easy. Even considering the discount of user distribution, it is 8 times. Three times more than now, this is the generation gap.

What is said above is excellent in theory. But after all, it is only theoretical. There are real goods, which were used in Trump's inaugural speech in the United States. But at present, this thing can only be pasted by hand with multi-layer lens materials. But also requires extremely high accuracy. This leads to extremely high antenna prices.

As far as I know, it is a breakthrough in China at present, and the relevant technology is finally available. It is said that the equipment of a factory is really excellent in the third-party field test. But is this hand-picked? How high is the yield? Still no way to know.

High price or trivial matter. For communication guarantee, it is only used for a short time. You can also sign a service contract with the manufacturer to ensure that the antenna is replaced immediately if its performance is insufficient. Ordinary 5G station antennas should be used outdoors for a long time. The mechanical structure of this high-precision plastic (polymer material) product will definitely change if it is exposed to the wind and the sun. Electromagnetic wave lenses are just afraid of mechanical structure changes.

All three domestic operators are interested, and there are indeed pilots. There may also be public bidding. But in the end, whether it can meet the network demand is still the same sentence: it needs practice to test.