1. 6GHz high frequency challenge
Consumer devices with common connectivity technologies like Wi-Fi, Bluetooth, and cellular only support frequencies up to 5.9GHz, so components and devices used to design and manufacture have historically been optimized for frequencies below 6 GHz for The evolution of tools to support up to 7.125 GHz has a significant impact on the entire product lifecycle from product design and validation through to manufacturing.
2. 1200MHz ultra-wide passband challenge
The wide frequency range of 1200MHz presents a challenge to the design of the RF front-end as it needs to provide consistent performance across the entire frequency spectrum from the lowest to the highest channel and requires good PA/LNA performance for covering the 6 GHz range. linearity. Typically, performance begins to degrade at the high-frequency edge of the band, and devices need to be calibrated and tested to the highest frequencies to ensure they can produce the expected power levels.
3. Dual or tri-band design challenges
Wi-Fi 6E devices are most commonly deployed as dual-band (5 GHz + 6 GHz) or (2.4 GHz + 5 GHz + 6 GHz) devices. For the coexistence of multi-band and MIMO streams, this again places high demands on the RF front-end in terms of integration, space, heat dissipation, and power management. Filtering is required to ensure proper band isolation to avoid interference within the device. This increases design and verification complexity because more coexistence/desensitization tests need to be performed and multiple frequency bands need to be tested simultaneously.
4. Emissions limit challenge
To ensure peaceful coexistence with existing mobile and fixed services in the 6GHz band, equipment operating outdoors is subject to the control of the AFC (Automatic Frequency Coordination) system.
5. 80MHz and 160MHz high bandwidth challenges
Wider channel widths create design challenges because more bandwidth also means more OFDMA data carriers can be transmitted (and received) simultaneously. The SNR per carrier is reduced, so higher transmitter modulation performance is required for successful decoding.
Spectral flatness is a measure of the distribution of power variation across all subcarriers of an OFDMA signal and is also more challenging for wider channels. Distortion occurs when carriers of different frequencies are attenuated or amplified by different factors, and the larger the frequency range, the more likely they are to exhibit this type of distortion.
6. 1024-QAM high-order modulation has higher requirements on EVM
Using higher-order QAM modulation, the distance between constellation points is closer, the device becomes more sensitive to impairments, and the system requires higher SNR to demodulate correctly. The 802.11ax standard requires the EVM of 1024QAM to be < −35 dB, while 256 The EVM of QAM is less than −32 dB.
7. OFDMA requires more precise synchronization
OFDMA requires that all devices involved in the transmission be synchronized. The accuracy of time, frequency, and power synchronization between APs and client stations determines overall network capacity.
When multiple users share the available spectrum, interference from a single bad actor can degrade network performance for all other users. Participating client stations must transmit simultaneously within 400 ns of each other, frequency aligned (± 350 Hz), and transmit power within ±3 dB. These specifications require a level of accuracy never expected from past Wi-Fi devices and require careful verification.
Post time: Oct-24-2023
