Extending the reverberation chamber using a channel emulator for characterisation of over-the-air performance of multiple-input–multiple-output wireless devices

2015 ◽  
Vol 9 (5) ◽  
pp. 555-562 ◽  
Author(s):  
Christian S. Patané Lötbäck ◽  
Anton Skårbratt ◽  
Charlie Orlenius
2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Xiaoming Chen ◽  
Jian Yang

Most of previous studies on diversity gains and capacities of multiantenna systems assumed independent and identically distributed (i.i.d.) Gaussian noises. There are a few studies about the noise correlation effects on diversity gains or MIMO capacities, however, by simulations only. In this paper, the maximum ratio combining (MRC) diversity gain and multiple-input multiple-output (MIMO) capacity including correlated noises are presented. Based on the derived formulas, measurements in a reverberation chamber are performed for the first time to observe the effect of noise correlations on diversity gains and MIMO capacities.


2018 ◽  
Vol 12 (11) ◽  
pp. 1828-1833
Author(s):  
Tien Manh Nguyen ◽  
Seung‐Ho Kim ◽  
Jin‐Young Jeong ◽  
Jong‐Hwa Kwon ◽  
Jae‐Young Chung

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Pillalamarri Laxman ◽  
Anuj Jain

Stealth wearable wireless devices are gaining much attention in the personal security and fashion designing industry. A multiple-input multiple-output wideband circularly polarized antenna wearable on a dress (textile-related), which is immune to bending, is described in this paper, where a wearable on fabric dress application uses the MIMO techniques. It consists of two multiple-input multiple-output types of antenna elements: the resonating elements are created resembling a beautiful peacock shape and the ground plane is appropriately designed. A voltage is applied to each antenna element; the ground plane contains a microstrip transmission line-fed and a rectangular upside-down L-shaped (vertically flipped) strip used for circular polarizing. The antenna covers a 3 dB axial-ratio-band-width (ARBW) value of 5.20–7.10 GHz and impedance bandwidth (S11 less than −10 dB) of 03.60–13.0 GHz. The proposed attachable wearable fabric (textile) multiple-input multiple-output wideband antenna exhibits envelope correlation coefficient (ECC) <0.02, diversity gain (DG) >9.96, channel capacity loss (CCL) <0.2 b/s/Hz, total active reflective coefficient (TARC) <−10 dB, mean effective gain (MEG) ratio within ±0.5 dB. There is dual-sense circular polarization in this antenna and high isolation between resonating elements (higher than 18). A specific absorption rate (SAR) of the proposed antenna for human tissues specimen is also discussed for different situations related to the human body. The overall size of the proposed CP textile MIMO antenna is 34 : 5 × 42 × 1 mm3. Because of its clothing layers (textile), practical performance, and miniature size, the designed MIMO antenna may be helpful for wearable on cloths on human body wireless devices and systems. The proposed antenna can be made unrecognizable because of the beautiful peacock design that can easily mix with the designs of fabric (in the fashion dress). The simulated antenna was fabricated with the help of conventional manual fabrication techniques and tested in real-time situations. The edge-to-edge distance amid the MIMO radiating antennas is 14.2 mm, and the achieved isolation is greater than 18 dB after optimization of the proposed antenna.


2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Juan D. Sánchez-Heredia ◽  
Paul Hallbjörner ◽  
Juan F. Valenzuela-Valdés ◽  
Thomas Bolin ◽  
Antonio M. Martínez-González

User influence on multiple-input multiple-output (MIMO) performance is studied for different dual antenna handsets specially designed to have good and bad MIMO performance. The study reveals that user influence can cause either improvement or degradation for different test objects, including a spread effect over the parameters. Differences in performance between good and bad handsets can be clear when they are measured without user influence, but become small under real person influence. This result illustrates the particular importance of user influence to characterize MIMO handsets.


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