• Journal of Communications and Networks
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• v.14 no.1
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• pp.1-9
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• 2012

We consider a receiving node, located at the origin, and a Poisson point process (PPP) that models the locations of the desired transmitter as well as the interferers. Interference is known to be non-Gaussian in this scenario. The capacity bounds for additive non-Gaussian channels depend not only on the power of interference (i.e., up to second order statistics) but also on its entropy power which is influenced by higher order statistics as well. Therefore, a complete statistical characterization of interference is required to obtain the capacity bounds. While the statistics of sum of signal and interference is known in closed form, the statistics of interference highly depends on the location of the desired transmitter. In this paper, we show that there is a tradeoff between entropy power of interference on the one hand and signal and interference power on the other hand which have conflicting effects on the channel capacity. We obtain closed form results for the cumulants of the interference, when the desired transmitter node is an arbitrary neighbor of the receiver. We show that to find the cumulants, joint statistics of distances in the PPP will be required which we obtain in closed form. Using the cumulants, we approximate the interference entropy power and obtain bounds on the capacity of the channel between an arbitrary transmitter and the receiver. Our results provide insight and shed light on the capacity of links in a Poisson network. In particular, we show that, in a Poisson network, the closest hop is not necessarily the highest capacity link.

• Journal of Communications and Networks
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• v.6 no.2
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• pp.106-111
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• 2004

The uplink capacity and the interference statistics of the sectors of the cigar-shaped W-CDMA microcells are studied. A model of 9 base station, assumed to be in a long tunnel, is used for the uplink analysis. The capacity and the interference statistics of the microcells are studied for different sector ranges, different propagation exponents, different antenna sidelobe levels, and different bend losses.

• Journal of Communications and Networks
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• v.16 no.1
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• pp.10-17
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• 2014

This work investigates two important performance metrics of underlay cooperative cognitive radio (CR) networks: Interference cumulative distribution function of licensed users and outage probability of unlicensed users. These metrics are thoroughly analyzed in realistic operating conditions such as imperfect fading channel information and strict transmit power constraint, which satisfies interference power constraint and maximum transmit power constraint, over Nakagami-m fading channels. Novel closed-form expressions are derived and subsequently validated extensively through comparisons with respective results from computer simulations. The proposed expressions are rather long but straightforward to handle both analytically and numerically since they are expressed in terms of well known built-in functions. In addition, the offered results provide the following technical insights: i) Channel information imperfection degrades considerably the performance of both unlicensed network in terms of OP and licensed network in terms of interference levels; ii) underlay cooperative CR networks experience the outage saturation phenomenon; iii) the probability that the interference power constraint is satisfied is relatively low and depends significantly on the corresponding fading severity conditions as well as the channel estimation quality; iv) there exists a critical performance trade-off between unlicensed and licensed networks.

• Journal of Internet Computing and Services
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• v.22 no.5
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• pp.1-8
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• 2021

Small-cells in heterogeneous networks are one of the important technologies to increase the coverage and capacity in 5G cellular networks. However, due to the randomly arranged small-cells, co-tier and cross-tier interference increase, deteriorating the system performance of the network. In order to manage the interference, some channel management methods use fractional frequency reuse(FFR) that divides the cell coverage into the inner region(IR) and outer region(OR) based on the distance from the macro base station(MBS). However, since it is impossible to properly measure the distance in the method with FFR, we propose a new interference aware FFR(IA-FFR) method to enhance the system performance. That is, the proposed IA-FFR method divides the MUEs and SBSs into the IR and OR groups based on the signal to interference plus noise ratio(SINR) of macro user equipments(MUEs) and received signals strength of small-cell base stations(SBSs) from the MBS, respectively, and then dynamically assigns subchannels to MUEs and small-cell user equipments. As a result, the proposed IA-FFR method outperforms other methods in terms of the system capacity and outage probability.

• Proceedings of the IEEK Conference
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• 2000.07a
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• pp.121-124
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• 2000

In this paper, we evaluate the interference statistics between the competiting wideband CDMA systems, and optimize the frequency coordination between Wideband-CDMA systems by the Monte-Carlo methodology. We develop the simulator to analyze the radio interference between CDMA systems. It can calculate or estimate the probability of interference from adjacent frequency band, which is also power controlled. We simulate the interference effects between two Wideband CDMA systems. We present the required carrier distance and zone for two operators to meet the required coverage efficiency and outage probability of Signal to interference plus noise ration (SINR).

• Journal of Satellite, Information and Communications
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• v.4 no.2
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• pp.46-51
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• 2009

This paper addresses the calculation method of the interference produced between the LEO(Low Earth Orbit) satellite constellation and Terrestrial system operating in the same frequency and area. We describes the procedure used in the numerical computation of the statistics of the total interference produced by interference system. The presented results are applied for mutual protection of LEO satellite constellation and FS system during system design phase.

• ETRI Journal
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• v.33 no.3
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• pp.320-325
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• 2011

This paper considers the effects of simultaneous correlated multipath fading and shadowing on the performances of a signal-to-interference ratio (SIR)-based dual-branch selection combining (SC) diversity receiver. This analysis includes the presence of cochannel interference. A generalized fading/shadowing channel model in an interference-limited correlated fading environment is modeled by generalized-K distribution. Closed-form expressions are obtained for probability density function and cumulative distribution function of the SC output SIR, as well as for the outage probability. Based on this, the influence of various fading and shadowing parameter values and the correlation level on the outage probability is examined.

• Asian Oncology Nursing
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• v.12 no.4
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• pp.339-346
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• 2012

Purpose: The purpose of this study was conducted to identify the impact of Symptom Severity and Symptom Interference on Sleep Disturbance among cancer patients. Methods: This study was conducted from October 8th to October 25th, 2012. One hundred eight cancer patients were recruited from S city in Korea. The instruments used in this study were the Symptom Severity, Symptom Interference and the Sleep Disturbance scales for patients with cancer. Data were analyzed using descriptive statistics, t-test, ANOVA, Pearson correlation coefficients and multiple regression with the SPSS/WIN 20.0 program. Results: The Sleep Disturbance for cancer patients showed a significant relationship with Symptom Interference and cancer stage. The significant factors influencing Sleep Disturbance were Symptom Severity and Symptom Interference. They explained 40.5% of the variance in stage IV. Conclusion: Patients with cancer experienced Symptom Severity and Symptom Interference which led to a negative effect on Sleep Disturbance. The results suggest that intervention programs to reduce Symptom Severity, Symptom Interference could improve Sleep Disturbance for cancer patients.

• Journal of Internet Computing and Services
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• v.22 no.6
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• pp.9-15
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• 2021

In ultra-dense heterogeneous networks, the amount of interference from small-cell base stations(SBS) to macro-cell user equipments (MUEs) increases significantly as the number of SBSs increases and it causes the MUEs to decrease the signal-to-interference and noise ratio(SINR) and system capacity. In this paper, we propose a small-cell based cooperative multi-point(CoMP) communication scheme that can guarantee the performance of MUEs even when the number of SBSs increases. In the proposed scheme, MUEs first find SBSs that give signal strength equal to or greater than a given SINR threshold and then they are served by different numbers of the selected SBSs using CoMP to improve the performance of MUEs. Simulation results show that the proposed small-cell based CoMP scheme outperforms other interference management or CoMP schemes in terms of the SINR and system capacity of MUEs.

• Journal of Korean Academic Society of Home Health Care Nursing
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• v.24 no.2
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• pp.189-199
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• 2017

Purpose: This study aimed to investigate the effects of foot bath therapy on the symptom intensity, distress, and interference with usual activities due to chemotherapy-induced peripheral neuropathy (CIPN) in patients with metastatic and recurrent cancer. Methods: Foot bath therapy was administered to the experimental group for >8 sessions in 2 weeks, and the chemotherapy-induced peripheral neuropathy assessment tool (CIPNAT) was used to measure its effects on the symptom intensity, distress, and interference with usual activities due to CIPN. SPSS was used to perform data analyses including descriptive statistics, chi-square test, Fisher's exact test, t-test, paired t-test, and repeated measures ANCOVA. Results: A statistically significant difference in the variation of the symptom intensity, distress, and interference with usual activities due to CIPN was observed between the two groups; however, a statistically insignificant difference was observed between the groups and time of interaction. Conclusion: Foot bath therapy can be used as a simple and effective clinical or home care nursing intervention to improve the symptom intensity, distress and interference with usual activities due to CIPN.