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标题: Wifi7|IPQ9554-IPQ9574-QCN9274-QCN6274-4K-QAM-advanced modulation scheme [查看完整版帖子] [打印本页]

时间: 2023-5-26 11:30

作者: wifi6 标题: Wifi7|IPQ9554-IPQ9574-QCN9274-QCN6274-4K-QAM-advanced modulation scheme

There are many R&D companies working on wifi7. I believe that soon, wifi7 routers and other products will be launched gradually. Wallys, as a company that develops and produces communication products, is no exception. Wifi7 products are in progress and will meet you soon.
Different companies use different wifi7 chips. Wallys wifi7 products use Qualcomm chips, such as IPQ9554, IPQ9574, QCN9274, QCN6274, etc., to meet different needs of customers.
WiFi7 technical standard:
1. The technical standard of wifi7 is named 802.11be. In fact, this is just a name and has no real meaning.
2. 802.11be can also be called EHT (Extremely High Throughput), which means extremely high throughput.
3. In essence, it is describing that the network has fast and large transmission speed and transmission content.
4. 320MHz channel bandwidth, thanks to the wider channel and capacity gain of the 6GHz spectrum, Wi-Fi 7 can provide a huge throughput gain, Wi-Fi 7 can provide a peak rate of more than 40 Gbps, which is the first of Wi-Fi 6E 4 times.
5. At the same time, WiFi 7 also has 4K-QAM, a transmission rate up to 30Gbps, and the overall rate can reach 3 times that of WiFi6.

6. The application range of the current WiFi network is getting wider and wider, and it has a high utilization rate in video, office, game, cloud computing and other scenarios.
One of the most important points in wifi7 is 4k-QAM. Many people don’t know much about it. Let’s introduce it in detail below.
What is the principle of QAM?
Let's start with the simplest signal.
According to the trigonometric function formula expansion is:
In this way, the signal s(t) is expanded into the sum of two quadrature signals with a phase difference of 90°. The two quadrature signal components are the In-phase signal and the Quadrature signal.
These two quadrature components are shown in the figure below and are 90° out of phase.
These two orthogonal signals, after passing through the DA converter, come to our analog channel. We need to modulate these two signals separately, so that both signals can get on the high-speed train of radio frequency carrier. The processing of QAM in the analog part is not complicated. I/Q signals can share a frequency source LO, and then directly up-convert the frequency through the mixer. Only in the Q channel, the local oscillator signal needs a 90° phase shift to match the Q (t) Orthogonality.

In the digital signal, we introduced the concept of a bit, which is the bit of Bitcoin, code-named B, so expensive, 1 Bitcoin is now worth 150,000 yuan, OMG.
The BIT of a digital signal is the bit of 0 and 1 in the binary number, the unit of measurement of the amount of information, and the smallest unit of the amount of information. The information contained in one bit of a binary number is one bit, such as the binary number 0100 is 4 bits. A bit can contain 2 pieces of information (0 or 1), and 4 bits can contain 2^4 pieces of information. So the more bits, the greater the amount of information that can be transmitted. So in theory, the larger m in m-QAM, the larger the amount of information that can be transmitted, and the faster the transmission rate. So the latest wifi7 standard directly reaches 4k-QAM, and a signal contains 12 bits.

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https://www.txrjy.com/forum.php?mod=attachment&aid=NTc5OTg4fDE5MjMyNjFhfDE3MzE3OTU2NDR8MHww

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https://www.txrjy.com/forum.php?mod=attachment&aid=NTc5OTg5fDBiYmViODNkfDE3MzE3OTU2NDR8MHww

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https://www.txrjy.com/forum.php?mod=attachment&aid=NTc5OTkxfDdjZDNhMDNjfDE3MzE3OTU2NDR8MHww

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附件: QAM4.png (2023-5-26 11:30, 33.73 KB) / 下载次数 0
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