Hand Blockage Modeling and Beamforming Codebook Mitigation Strategies

Hand and body blockage are known to result in significant performance degradation at millimeter wave carrier frequencies. A number of prior works have proposed statistical models to capture the spatial region lost due to blockage and the associated losses incurred in signal strength over this region. In particular, it is understood that while a hard hand grip can lead to substantial losses, a more relaxed/looser hand grip can lead to moderate losses. However, all these works consider only the signal strength degradation with blockage mitigation mechanisms consisting of densification of the network and the use of more antenna modules at the user equipment end. In practice, the number of antenna modules in a user equipment may be limited leading to the need for more novel blockage mitigation strategies. Towards this goal, in this work, we show that the presence of the hand on top/near an antenna module can distort the observed amplitude and phase of the array response. We also show that a non-directional analog beamforming codebook enhancement can de-randomize some of the phase distortions and recover some of the gains lost due to the hand with a directional beamforming codebook.