Racom (Czechia)

In this letter, we introduce a novel quasi-orthogonal full-rate space-time line code (FR-QSTLC) for an arbitrary number of transmit antennas and four receiver antennas. Its fully analytical examination and the benchmark of full-rate STLCs are provided, and the results are compared in terms of average bit error ratio (ABER) and diversity gain. Due to its quasi-orthogonal properties, the proposed FR-QSTLC exhibits an asymptotic SNR gain of up to 3 dB compared to its orthogonal two-antenna counterpart and outperforms all the other linearly-decoded full-rate STLCs.

In the last decade, in order to realize reliable wireless communication link in a wide range of radio-frequency (RF) spectrum, the group of IEEE 802.11 technologies has been significantly expanded. In this paper, attention is devoted to the IEEE 802.11ah/af systems developed for Wireless Fidelity (Wi-Fi) based communication with a support of the Internet-of-Things (IoT) concept in the sub-1GHz bands. Two MATLAB-based simulators are introduced to explore basic features of both systems on physical (PHY) layer level. A simple performance study of both systems under different channel conditions, evaluated in terms of bit and modulation error ratio (BER and MER), is provided to validate the simulators. The single-input single-output and multiple-input multiple-output (SISO and MIMO) technologies are also briefly compared. Simulation results show that systems IEEE 802.11ah and IEEE.802.11af can complement each other in various transmission scenarios and use cases.

Human granulocytic anaplasmosis (HGA) is a tick-borne, acute illness with increasing incidence [1]. It is caused by Anaplasma phagocytophilum proved to have a tick vector Ixodes ricinus in Europe. HGA is usually a mild or even asymptomatic illness with non-specific influenza-like symptoms, and is associated with variable but suggestive laboratory alterations. When comparing HGA with human ehrlichiosis caused by Ehrlichia chaffeensis, beside differences in geographical distribution, there is a close association with higher hospitalization rate (36% vs. 48.6%), morbidity and life-threatening complications (e.g. adult respiratory distress syndrome, disseminated intravascular coagulopathy, meningoencephalitis, renal failure) and mortality (0.6% vs. 1.9%) in E. chaffeensis cases [1]. A rush, as a clinical presentation, is also more frequently reported in patients with E. chaffeensis. HGA occurs in previously healthy individuals, and the disease severity is associated with the degree of compromised immunity of infected patients. The diagnosis is confirmed retrospectively using specific laboratory tests, which include positive polymerase chain reaction (PCR), identification of A. phagocytophilum in a culture of acute-phase blood, or the detection of specific antibodies to A. phagocytophilum in convalescent-phase serum samples. Doxycycline provides rapid and effective treatment.