An Overview of Millimeter Wave Communications for Military Applications

The use of millimeter wave for Defence communications can offer a number of benefits to the user. Apart from the benefit of wider capacity, millimeter wave also offers ability to provide secure and survivable communication in the presence of enemy threats. In this paper, some of the important benefits for Defence communication are reviewed. An overview of millimeter wave military communication applications, technology development, present status and trends are also given

Array Configuration-Agnostic Personal Voice Activity Detection Based on Spatial Coherence

Personal voice activity detection has received increased attention due to the growing popularity of personal mobile devices and smart speakers. PVAD is often an integral element to speech enhancement and recognition for these applications in which lightweight signal processing is only enabled for the target user. However, in real-world scenarios, the detection performance may degrade because of competing speakers, background noise, and reverberation. To address this problem, we proposed to use equivalent rectangular bandwidth ERB-scaled spatial coherence as the input feature to train an array configuration-agnostic PVAD network. Whereas the network model requires only 112k parameters, it exhibits excellent detection performance and robustness in adverse acoustic conditions. Notably, the proposed ARCA-PVAD system is scalable to array configurations. Experimental results have demonstrated the superior performance achieved by the proposed ARCA-PVAD system over a baseline in terms of the area under receiver operating characteristic curve and equal error rate.Comment: Accepted by INTER-NOISE 2023. arXiv admin note: text overlap with arXiv:2211.0874

The Effect of a Voice Activity Detector on the Speech Enhancement

A multimicrophone speech enhancement algorithm for binaural hearing aids that preserves interaural time delays was proposed recently. The algorithm is based on multichannel Wiener filtering and relies on a voice activity detector (VAD) for estimation of second-order statistics. Here, the effect of a VAD on the speech enhancement of this algorithm was evaluated using an envelope-based VAD, and the performance was compared to that achieved using an ideal error-free VAD. The performance was considered for stationary directional noise and nonstationary diffuse noise interferers at input SNRs from 10 to +5dB. Intelligibility-weighted SNR improvements of about 20dB and 6dB were found for the directional and diffuse noise, respectively. No large degradations (<1dB) due to the use of envelope-based VAD were found down to an input SNR of 0dB for the directional noise and 5dB for the diffuse noise. At lower input SNRs, the improvement decreased gradually to 15dB for the directional noise and 3dB for the diffuse noise.12 page(s

Aerospace Medicine and Biology: A continuing bibliography with indexes, supplement 182, July 1978

This bibliography lists 165 reports, articles, and other documents introduced into the NASA scientific and technical information system in June 1978