Investigations into the feasibility of multiple input multiple output techniques within the HF band: Preliminary results

Abstract

[1] The concept of multiple input multiple output (MIMO) has become a productive area of research in the field of wireless communications with the aim of delivering increased data throughput. However, to date, MIMO research has focused primarily on short-range communications within the VHF, UHF, and SHF bands, and very little research has been conducted toward exploiting MIMO techniques for long-range communications within the HF band. Between September 2007 and September 2008, several experimental campaigns were conducted to investigate the feasibility of applying MIMO techniques within the HF band. The results of measurements over a 255 km path from Durham to Leicester within the United Kingdom are presented in this paper with particular emphasis on the use of heterogeneous antenna arrays at the transmitter and receiver.

Polarization diversity in a long‐haul transequatorial HF link from Antarctica to Spain

“…They maintained a BER of around 10 −3 , which is considered acceptable for an HF modem. In [ Abbasi et al , ] and [ Gunashekar et al , ] the authors increased the channel capacity using MIMO due to the low cross correlation of signals transmitted and received by different antennas. They concluded that to achieve a lower cross‐correlation factor, the homogeneous arrays should be replaced by collocated antennas and heterogeneous arrays.…”

Experimental study of wide area SIMO for ionospheric HF radio links

“…There are relatively few papers devoted to the use of the cooperative SIMO technology in HF channels [4,5]. The majority of them are devoted to the use of MIMO, based on the polarization diversity of the received signal.…”

MIMO communications within the HF band using compact antenna arrays

“…In this section, observations and results are presented from HF‐MIMO measurements in which both the “X‐Y‐Z” array and the ground symmetric loop (GSL) array were simultaneously employed. The results from these arrays are compared with those of the crossed inverted “V” wire array that in earlier measurements exhibited consistently low levels of decorrelation between the two perpendicularly oriented wires [ Gunashekar et al , 2008, 2009a, 2009b; Warrington et al , 2008]. Note that a commonly used correlation coefficient value that is often cited as a threshold below which signals are generally considered to be independent of each other is 0.7 [ Waldschmidt et al , 2002; Mtumbuka et al , 2005].…”

“…The nominal transmission frequency was 5.255 MHz (TX‐1: 5.255020 MHz; TX‐2: 5.255030 MHz). As discussed by Gunashekar et al [2009b], the frequency offsets were necessary as a means of identifying the different transmit signals.…”