| 1. |
- Eliardsson, Patrik, et al.
(författare)
-
Analysis of the local HF interference environment at a military platform
- 2013
-
Ingår i: Nordic HF Conference Proceedings 2013. ; , s. 3.4-
-
Konferensbidrag (refereegranskat)abstract
- High frequency (HF) communications are of vital importance for modern military operations. However, HF channels are touchy and unpredictable, prone to noise, fading, jamming, and interference. Therefore, a number of prediction tools for channel selection have been developed. However, existing tools do not consider the local actual electromagnetic interference at receivers located on navy and army platforms. Measurements on military platforms show that also the local interference environment can be crucial and has large variations in frequency and time. In this paper we analyze the levels and dynamics of local interference from a typical military platform. We show that the variations regarding interference waveform can be very large between two consecutive seconds of measurement. This means that the interference impact in terms of bit error probability also will be very large between such consecutive seconds. The overall conclusion is that future methods for HF-frequency selection would be significantly improved by considering the characteristics of local interference from electrical equipment.
|
|
| 2. |
- Ferrer Coll, Javier, 1983-, et al.
(författare)
-
Characterization of Electromagnetic Properties in Iron-Mine Production Tunnels
- 2012
-
Ingår i: Electronics Letters. - : Institution of Engineering and Technology. - 0013-5194 .- 1350-911X. ; 48:2, s. 62-63
-
Tidskriftsartikel (refereegranskat)abstract
- Modern underground mines require reliable wireless communication for transmitting voice data, operating surveillance cameras, and monitoring mining equipment such as heavy vehicles. The electromagnetic characteristics of mines therefore have to be considered when determining the type of wireless technology for such critical applications. In this reported work, measurements of radio interference levels, path loss, and multipath propagation are performed in the world's now largest iron ore mine, situated in Sweden, to determine a suitable wireless technology for this mine.
|
|
| 3. |
- Fors, Karina, et al.
(författare)
-
A simple measurement method to derive the impulsiveness correction factor for communication performance estimation
- 2013
-
Ingår i: IEEE transactions on electromagnetic compatibility (Print). - : IEEE. - 0018-9375 .- 1558-187X. ; 55:5, s. 834-841
-
Tidskriftsartikel (refereegranskat)abstract
- Today, no simple methods are available for measurements of interference signals that give a proper indication of the impact in terms of the bit error probability (BEP) on a digital radio receiver. Such measure should quantify the corresponding impact and the measurements should be relatively easy to perform. By only using the root mean square (RMS) value of the interference average power the BEP can be underestimated with several magnitudes. To address this problem, an impulsiveness correction factor (ICF) has earlier been proposed to adjust for these errors. The ICF opens up for considerably more accurate BEP estimations whereas the simplicity in the calculations is maintained. However, how to determine the ICF for an arbitrary interference source through measurements has not earlier been known. In this paper, we show that the ICF can be obtained in two alternative ways. One way is to use the measured amplitude probability distribution (APD). The other way is to use the peak- and RMS values from standard measurement detectors. Both methods take the interference waveform properties into consideration and the BEP can thus be more accurately estimated.
|
|
| 4. |
- Linder, Sara, et al.
(författare)
-
Effects of intersystem interference in HF systems
- 2013
-
Ingår i: Nordic HF Conference Proceedings 2013. ; , s. 3.2-
-
Konferensbidrag (refereegranskat)abstract
- High Frequency (HF) communications are of vital importance for modern military operations. Mainly because of it long communication range at a fraction of the cost of heavily burdened satellite communications frequencies. However, the noise and interference levels are high at this frequency band. Hence, intersystem interference analysis of communication platforms is an important action in order to ensure the communication capabilityIn this paper we show that local interference can have significant impact on the HF communication performance. The effects from interference on the HF communication system is analyzed and shown in different military scenarios as an increased bit error probability leading to a decreased operating range of the communication system or lower data rate for the service. The considered interference source is medical equipment which emission spectrum is measured and show high levels of interference in the HF band. The overall conclusion is that local interference has to be considered for HF-frequency selection. This speaks for extending present methods for frequency selection with funtionality to avoid that local interference disrupt vital HF-communication services.
|
|
| 5. |
- Stenumgaard, Peter, 1964-
(författare)
-
A simple method for dynamic frequency allocation considering the total interference impact on the bit error probability
- 2011
-
Ingår i: <em>EMC Europe 2011 York</em>. ; , s. 654-657
-
Konferensbidrag (refereegranskat)abstract
- Initiatives to open certain frequency bands for Dynamic Spectrum Access (DSA) are ongoing and examples are WAPECS and White Space Coalition. A key issue in DSA is how to measure both the occupancy and other undesired interference in an open frequency band to make a decision whether or not it can be used for a certain service. A common method to detect unknown interference is to consider the interference power only by using energy detection. This can give large errors since the interference impact can be severely dependent on the interference waveform. In this paper, a frequency allocation method is shown where the total interference waveform properties, in terms of interference impact, are estimated by a simple measurement. An example is shown where the frequency allocation algorithm outperforms a traditional allocation based on pure interference power detection only.
|
|
| 6. |
- Stenumgaard, Peter, 1964-, et al.
(författare)
-
An Early-Warning Service for Emerging Communication Problems in Security and Safety Applications
- 2013
-
Ingår i: IEEE Communications Magazine. - : IEEE. - 0163-6804 .- 1558-1896. ; 51:5, s. 186-192
-
Tidskriftsartikel (refereegranskat)abstract
- Experience has shown that unpredictable disruption of communications during emergency operations can have severe consequences both for personal safety and for the ability to conduct a successful operation. An early-warning service for emerging communication disruption due to both unintentional interference and jamming, would therefore be a significant contribution for increased safety and security in such operations. We propose a solution for such an early-warning service both on the terminal and on higher system level. The solution is based on historical recorded data of both local and global information such as signal-to-interference ratio, interference classification, and position. We show by an example that with this service implemented, the operator will have increased time to take actions before a disruption occurs on a specific terminal.
|
|
| 7. |
- Stenumgaard, Peter, 1964-, et al.
(författare)
-
Electromagnetic Interference on Tactical Radio Systems from Co-located Medical Equipment
- 2013
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- On military camps for joint international operations, the intersystem-interference situations can be highly unpredictable and scenario changes can occur very fast. For such situations it is highly important to perform intersystem-interference analyses even for electromagnetic interference from other electric equipment than intentional transmitters. One example of such interference source to consider is medical equipment from field hospitals since these can contain a large amount of interfering equipment. In this paper, we show examples of necessary safety distances between medical equipment and tactical radio systems at military camps for international missions. We give an example of how wideband electromagnetic interference can damage the interference reduction measure even for a wideband frequency hopping army combat radio.
|
|
| 8. |
- Stenumgaard, Peter, 1964-, et al.
(författare)
-
Electromagnetic Interference on Tactical Radio Systems from Collocated Medical Equipment on Military Camps
- 2012
-
Ingår i: IEEE Communications Magazine. - 0163-6804 .- 1558-1896. ; 50:10, s. 64-69
-
Tidskriftsartikel (refereegranskat)abstract
- On military camps for joint international operations, the intersystem interference can be highly unpredictable, and situation changes can occur very fast. For such situations it is highly important to perform intersystem interference analyses not only for intentional transmitters but also for electromagnetic interference from other electric equipment. One example of such an interference source to consider is medical equipment in field hospitals since the hospitals can contain a large amount of interfering equipment. In this article, we show examples of necessary safety distances between medical equipment and tactical radio systems at military camps for international missions. We give an example of how wideband electromagnetic interference can degrade the performance even for a wideband frequency hopping army combat radio.
|
|
| 9. |
- Stenumgaard, Peter, 1964-, et al.
(författare)
-
Extension of the impulsiveness correction factor for several modulation schemes and various interfering signals for interference control in dynamic wireless applications
- 2012
-
Ingår i: IET Communications. - : The Institution of Engineering and Technology. - 1751-8628 .- 1751-8636. ; 6:10, s. 1229-1233
-
Tidskriftsartikel (refereegranskat)abstract
- The impulsiveness correction factor (ICF) has earlier been proposed as a simple measure for estimating the effect from pulsed interference on binary phase shift keying modulated digital radio systems. The advantage is that with the ICF, large errors introduced by the additive white Gaussian noise interference approximation can be reduced significantly, whereas the simplicity in interference analyses can be maintained. In this study, the ICF is further developed for other modulation schemes, such as M-phase shift keying and M -quadrature amplitude modulation and for a larger set of interference types. The results show that for one pulsed interference signal the ICF is suitable for all investigated modulation schemes. If the interference is a mixtureof modulated and pulsed signals or several pulsed signals the authors suggest and valuate ways to extend the ICF.
|
|
| 10. |
- Stenumgaard, Peter, 1964-, et al.
(författare)
-
Intersystem Interference Model for Frequency Hopping Systems
- 2012
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In this paper a method for calculating the impact of intersystem interference between frequency hopping systems is proposed. The results are given in form of the average bit error probability over all frequencies used by the system. The method includes both the transmitter spectrum with sidebands and the receiver selectivity with sidebands. Furthermore, the effects from partially overlapping frequency hopping bands are included in the model. A strength of the model is that it can be generalized to an arbitrary number of interfering frequency hopping systems. Moreover, in addition to frequency hopping systems, interference on a fix frequency from different kinds of systems can also be included. If measured interference spectra, for example from a computer or a background, are available they can be incorporated in the calculations as well. Results from using the model show that it is important to use correct models of both the transmitter spectrum and receiver sidebands. If the effects from transmitter sidebands and/or receiver selectivity is neglected the resulting bit error probability can be severely underestimated.
|
|
