Massive MIMO for RFID

无线物联网（IoT）设备耗电量非常少，手表大小的电池能够维持设备的整个使用寿命。目前的无线通信技术依赖于占空比，既难以同步又低功耗。被动唤醒无线电利用与数据包一起发送的单独的“唤醒”数据包。然后，无线电可以保持深度睡眠状态，直到事件唤醒包获得其射频能量，然后该能量可以打开无线电并发出信号，决定是否发送或接收数据。由于采用这种设计的设备大部分时间处于深度睡眠状态，而不是占空循环，因此将显著改善功耗。然而，它的代价是接收器灵敏度较低，电流最大唤醒范围为~10m，这对于大多数物联网应用来说太低了。为了克服这个问题，我们建议在唤醒无线电架构中使用SAW（表面声波）器件作为电压倍增器。这些设备具有非常高的增益和q因子，这将使无线电设计从宽带转向窄带。该项目将通过在无线电设计中设计、制造和实施SAW设备的过程，研究提高唤醒无源无线电的灵敏度/范围的机会。除此之外，该项目还需要修改当前的架构，以适应新的窄带需求。

Wireless IoT (internet of things) devices use very little power, with watchsized batteries capable of lasting a device's entire lifetime. Current wireless communication technology relies on duty cycling, which is both difficult to synchronise and power inefficient. Passive wake-up radio utilises a separate 'wake-up' packet sent alongside the data packets. The radio can then remain in deep-sleep until an incident wake-up packet has its RF energy harvested, and this energy can then switch the radio on and signal whether to transmit or receive data. Since the device spends most of its time in deep-sleep with this design, rather than duty cycling, it will result in significant power consumption improvements. However, it comes at the cost of lower receiver sensitivity and a current max wake-up range of ~10m, which is far too low to be viable for most IoT applications. To attempt to overcome this, we propose to use SAW (surface acoustic wave) devices within the wake-up radio architecture as a voltage multiplier. These devices have a very high gain & Q-factor, which will shift the radio design from broadband to narrowband. The project will investigate opportunities to improve the sensitivity/range of the wake-up passive radio through the process of designing, fabricating, and implementing SAW devices within the radio design. Alongside this, the project will require modification of current architecture to accommodate the new narrowband requirements presented.