MinDFul: Using double links for stabilizing mmWave wireless channels for application to autonomous vehicles and augmented reality

Applications that require short-range ultra-high bitrate communication, such as cable removal in virtual reality games and communication between autonomous vehicles, are examining solutions such as millimetre wave wireless (mmWave). When using mmWave, steerable directional antennas are used to mitigate the severe signal power attenuation common with high frequencies. Nonetheless, even small movements in the user device can cause a sudden drop in data-rate down (even to 0 bits/s) making mmWave channels unstable and unusable. To make the channel more stable for the aforementioned applications, which are vulnerable due to frequent blockages and fast movement, we designed and developed a robust solution based on a double link mmWave system. We duplicate the radio transceivers (RT) of a user device (UD) to increase the probability of finding line of sight to an access point (AP) representing the other side of the communication channel. The AP selects one RT of the UD for communication, based on continuous measurement of quality compared to the channel of the other RT. This concept was implemented in a laboratory environment and evaluated using a series of controlled experiments. The experiments serve to validate that using double links is feasible, and is considerably more robust and it can double the link utilization, compared to only using one mmWave link. These results show great promise for the concept, by demonstrating that using multiple mmWave links yields ultra-high bit-rate wireless communication with no disruption, even in the presence of blockages and mobility

Digitally-Compensated Wideband 60 GHz Test-Bed for Power Amplifier Predistortion Experiments

Millimeter waves will play an important role in communication systems in the near future. On the one hand, the bandwidths available at millimeter-wave frequencies allow for elevated data rates, but on the other hand, the wide bandwidth accentuates the effects of wireless front-end impairments on transmitted waveforms and makes their compensation more difficult. Research into front-end impairment compensation in millimeter-wave frequency bands is currently being carried out, mainly using expensive laboratory setups consisting of universal signal generators, spectral analyzers and high-speed oscilloscopes. This paper presents a detailed description of an in-house built MATLAB-controlled 60 GHz measurement test-bed developed using relatively inexpensive hardware components that are available on the market and equipped with digital compensation for the most critical front-end impairments, including the digital predistortion of the power amplifier. It also demonstrates the potential of digital predistortion linearization on two distinct 60 GHz power amplifiers: one integrated in a direct-conversion transceiver and an external one with 24 dBm output power