Pub Date : 2013-12-11DOI: 10.1109/PIMRC.2013.6666348
Hao Xu, Pinyi Ren
Intercell interference severely degrades the performance of cell-edge users in cellular networks. To effectively manage the intercell interference, a heuristic scheme that jointly considers user scheduling and power control is proposed for multicell orthogonal frequency division multiple-access (OFDMA) networks with BS cooperation and limited backhaul capacity. First, a greedy user scheduling is proposed, taking both channel gain and the cost of directional cooperation into consideration. This scheme schedules the cell-edge users of all cells in the same subchannels. Second, under the guiding of user scheduling, the interference among cell-edge users of different cells can be preferentially cancelled with zero-forcing precoding. Third, a two-step power control is conducted to further improve cell-edge users performance. In the first step, with the strong duality of the nonconvex optimization subproblem, we obtain the minimum power consumption that guaranteeing the cellcenter users' rate requirement. In the second step, the residual power of per cell can be utilized to maximize cell-edge users performance. Then, with the fixed user scheduling, the iteration among interference cancelation and power control can be conducted until the backhaul capacity constraints are satisfied. Performance analysis proves the convergence of the proposed algorithm, and shows the effectiveness of the user scheduling. Simulation results show that, the proposed algorithm achieves a significant improvement of sum-rate for cell-edge users with negligible rate degradation for cell-center users.
{"title":"Joint user scheduling and power control for cell-edge performance improvement in backhaul-constrained network MIMO","authors":"Hao Xu, Pinyi Ren","doi":"10.1109/PIMRC.2013.6666348","DOIUrl":"https://doi.org/10.1109/PIMRC.2013.6666348","url":null,"abstract":"Intercell interference severely degrades the performance of cell-edge users in cellular networks. To effectively manage the intercell interference, a heuristic scheme that jointly considers user scheduling and power control is proposed for multicell orthogonal frequency division multiple-access (OFDMA) networks with BS cooperation and limited backhaul capacity. First, a greedy user scheduling is proposed, taking both channel gain and the cost of directional cooperation into consideration. This scheme schedules the cell-edge users of all cells in the same subchannels. Second, under the guiding of user scheduling, the interference among cell-edge users of different cells can be preferentially cancelled with zero-forcing precoding. Third, a two-step power control is conducted to further improve cell-edge users performance. In the first step, with the strong duality of the nonconvex optimization subproblem, we obtain the minimum power consumption that guaranteeing the cellcenter users' rate requirement. In the second step, the residual power of per cell can be utilized to maximize cell-edge users performance. Then, with the fixed user scheduling, the iteration among interference cancelation and power control can be conducted until the backhaul capacity constraints are satisfied. Performance analysis proves the convergence of the proposed algorithm, and shows the effectiveness of the user scheduling. Simulation results show that, the proposed algorithm achieves a significant improvement of sum-rate for cell-edge users with negligible rate degradation for cell-center users.","PeriodicalId":210993,"journal":{"name":"2013 IEEE 24th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125329432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-12-11DOI: 10.1109/PIMRC.2013.6666374
Muhammet Fatih Bayramoglu, M. Juntti
A multirate transmission scheme to mitigate intersymbol interference (ISI) is proposed in this paper. The proposed method first decomposes the channel into two half-rate subchannels by employing successive interference cancellation (SIC). Then the channel is further decomposed into 2M parallel channels by applying the method recursively. We demonstrate that these sub-channels tend to become memoryless as M increases. The proposed reception algorithm can be implemented in frequency domain and thus, it has a complexity in the order of linear equalizers. The proposed transmission scheme does not employ any sort of linear pre-coding at the transmitter. Therefore, it does not increase the peak-to-average power ratio at all. Furthermore, the proposed transmission method can surpass even the genie aided decision feedback equalizer in terms of reliable throughput and it can get quite close to independent identically distributed (i.i.d.) capacity of the channel which is a quite important achievement for a practical equalizer.
{"title":"A multirate equalizer for inter-symbol interference channels based on successive interference cancellation","authors":"Muhammet Fatih Bayramoglu, M. Juntti","doi":"10.1109/PIMRC.2013.6666374","DOIUrl":"https://doi.org/10.1109/PIMRC.2013.6666374","url":null,"abstract":"A multirate transmission scheme to mitigate intersymbol interference (ISI) is proposed in this paper. The proposed method first decomposes the channel into two half-rate subchannels by employing successive interference cancellation (SIC). Then the channel is further decomposed into 2M parallel channels by applying the method recursively. We demonstrate that these sub-channels tend to become memoryless as M increases. The proposed reception algorithm can be implemented in frequency domain and thus, it has a complexity in the order of linear equalizers. The proposed transmission scheme does not employ any sort of linear pre-coding at the transmitter. Therefore, it does not increase the peak-to-average power ratio at all. Furthermore, the proposed transmission method can surpass even the genie aided decision feedback equalizer in terms of reliable throughput and it can get quite close to independent identically distributed (i.i.d.) capacity of the channel which is a quite important achievement for a practical equalizer.","PeriodicalId":210993,"journal":{"name":"2013 IEEE 24th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC)","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125841154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-12-11DOI: 10.1109/PIMRC.2013.6666707
K. Hiltunen
This study evaluates the performance of a scheme, where idle capacity cells are put into sleep mode to save energy. The evaluation is performed for a few different LTE network densification alternatives, and the network performance is compared from the daily energy consumption point of view. The obtained results indicate that the introduction of the sleep mode scheme results in 42-62% lower daily energy consumption, depending on the network densification alternative. Furthermore, the evaluated heterogeneous network deployments are found to be more energy-efficient than the densified macro deployment, which is a clear difference compared to scenarios without any energy saving schemes. If the sleep mode deployment is compared to a scheme, where underutilized capacity cells are completely switched off, the gain becomes equal to 26-43%. The results demonstrate also that the network energy consumption can be further reduced with the help of fast cell DTX. For example, if a fast cell DTX scheme reducing the idle state power consumption by 50% is assumed, the daily energy consumption becomes 31-37% lower than without fast cell DTX. Finally, the combination of fast cell DTX and sleep mode deployment results in 63-75% lower daily energy consumption compared to scenarios without any special energy saving schemes.
{"title":"Utilizing eNodeB sleep mode to improve the energy-efficiency of dense LTE networks","authors":"K. Hiltunen","doi":"10.1109/PIMRC.2013.6666707","DOIUrl":"https://doi.org/10.1109/PIMRC.2013.6666707","url":null,"abstract":"This study evaluates the performance of a scheme, where idle capacity cells are put into sleep mode to save energy. The evaluation is performed for a few different LTE network densification alternatives, and the network performance is compared from the daily energy consumption point of view. The obtained results indicate that the introduction of the sleep mode scheme results in 42-62% lower daily energy consumption, depending on the network densification alternative. Furthermore, the evaluated heterogeneous network deployments are found to be more energy-efficient than the densified macro deployment, which is a clear difference compared to scenarios without any energy saving schemes. If the sleep mode deployment is compared to a scheme, where underutilized capacity cells are completely switched off, the gain becomes equal to 26-43%. The results demonstrate also that the network energy consumption can be further reduced with the help of fast cell DTX. For example, if a fast cell DTX scheme reducing the idle state power consumption by 50% is assumed, the daily energy consumption becomes 31-37% lower than without fast cell DTX. Finally, the combination of fast cell DTX and sleep mode deployment results in 63-75% lower daily energy consumption compared to scenarios without any special energy saving schemes.","PeriodicalId":210993,"journal":{"name":"2013 IEEE 24th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132766649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-12-11DOI: 10.1109/PIMRC.2013.6666423
M. Maman, D. Miras, L. Ouvry
Wireless communications for Body Area Network (BAN) applications require an adaptable, dynamic and flexible Medium Access Control (MAC) to cope with a variety of application requirements. This protocol enables to collect multiple real-time motional and emotional sensors information at different places on the human body and to wirelessly transmit it towards dedicated devices or computers. The key requirements in BAN applications are low power consumption, low latency and high reliability of communications. As body posture highly affects MAC protocols performances, we propose and have implemented a protocol based on BATMAC which automatically detects the shadowing effect and quickly adapts the relaying scheduling to BAN changes. Our protocol makes a trade-off between the quality of service and the energy consumption depending on the environment conditions and user activities and needs. Finally, we evaluate the performance of a heterogeneous network designed especially for BAN from a networking and radio perspective in different environments.
{"title":"Implementation of a self-organizing, adaptive, flexible and ultra low-power MAC protocol for wireless Body Area Networks","authors":"M. Maman, D. Miras, L. Ouvry","doi":"10.1109/PIMRC.2013.6666423","DOIUrl":"https://doi.org/10.1109/PIMRC.2013.6666423","url":null,"abstract":"Wireless communications for Body Area Network (BAN) applications require an adaptable, dynamic and flexible Medium Access Control (MAC) to cope with a variety of application requirements. This protocol enables to collect multiple real-time motional and emotional sensors information at different places on the human body and to wirelessly transmit it towards dedicated devices or computers. The key requirements in BAN applications are low power consumption, low latency and high reliability of communications. As body posture highly affects MAC protocols performances, we propose and have implemented a protocol based on BATMAC which automatically detects the shadowing effect and quickly adapts the relaying scheduling to BAN changes. Our protocol makes a trade-off between the quality of service and the energy consumption depending on the environment conditions and user activities and needs. Finally, we evaluate the performance of a heterogeneous network designed especially for BAN from a networking and radio perspective in different environments.","PeriodicalId":210993,"journal":{"name":"2013 IEEE 24th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC)","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130226102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-12-11DOI: 10.1109/PIMRC.2013.6666171
C. Hellings, W. Utschick
Optimization of transmit strategies with linear transceivers in multiple-input multiple-output (MIMO) broadcast channels generally leads to nonconvex problems, which cannot be solved efficiently in a globally optimal manner. Instead, it is necessary to resort to suboptimal algorithms. In this paper, we evaluate the application of a gradient descent algorithm for the optimization of the energy efficiency in such a system. Since the quality of the obtained locally optimal solutions depends on the initialization, a successive stream allocation is introduced and combined with the gradient algorithm. Comparison with a globally optimal reference algorithm for the special case of single receive antennas shows that the obtained solutions are close to the global optimum. For the MIMO case, the energy per bit achievable with dirty paper coding, which is a lower bound for the case of linear transceivers, is used as benchmark, and good performance of the gradient-based methods is shown for MIMO systems as well.
{"title":"Energy efficiency optimization in the multiantenna downlink with linear transceivers","authors":"C. Hellings, W. Utschick","doi":"10.1109/PIMRC.2013.6666171","DOIUrl":"https://doi.org/10.1109/PIMRC.2013.6666171","url":null,"abstract":"Optimization of transmit strategies with linear transceivers in multiple-input multiple-output (MIMO) broadcast channels generally leads to nonconvex problems, which cannot be solved efficiently in a globally optimal manner. Instead, it is necessary to resort to suboptimal algorithms. In this paper, we evaluate the application of a gradient descent algorithm for the optimization of the energy efficiency in such a system. Since the quality of the obtained locally optimal solutions depends on the initialization, a successive stream allocation is introduced and combined with the gradient algorithm. Comparison with a globally optimal reference algorithm for the special case of single receive antennas shows that the obtained solutions are close to the global optimum. For the MIMO case, the energy per bit achievable with dirty paper coding, which is a lower bound for the case of linear transceivers, is used as benchmark, and good performance of the gradient-based methods is shown for MIMO systems as well.","PeriodicalId":210993,"journal":{"name":"2013 IEEE 24th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC)","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130045757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-12-11DOI: 10.1109/PIMRC.2013.6666584
Lei Zhao, Yide Wang, P. Chargé
In this paper, sum rate optimization of multiuser multiple-input multiple-output broadcast (MU-MIMO) communication systems with perfect channel state information (CSI) at the base station is investigated. Since power allocation is a signomial optimization problem in the presence of multiuser interference (MUI), it is not a convex problem in general. Several optimal solutions proposed in the literature have exponential computational complexity, which is hard to implement for practice. We propose an iterative water-filling algorithm that takes advantage of the classical simple water-filling principle. The proposed algorithm reduces significantly the computational complexity compared with the methods in the literature only with a negligible performance degradation. In addition, the generalized eigenvalue technique for beamforming design is utilized in this paper for minimizing MUI, the number of users and the number of antennas of each user can be arbitrary. Simulations show that the sum rate of the proposed method is close to the sum capacity of the MU-MIMO broadcast channel, especially in low signal-to-noise ratio (SNR) region.
{"title":"Efficient power allocation strategy in multiuser MIMO broadcast channels","authors":"Lei Zhao, Yide Wang, P. Chargé","doi":"10.1109/PIMRC.2013.6666584","DOIUrl":"https://doi.org/10.1109/PIMRC.2013.6666584","url":null,"abstract":"In this paper, sum rate optimization of multiuser multiple-input multiple-output broadcast (MU-MIMO) communication systems with perfect channel state information (CSI) at the base station is investigated. Since power allocation is a signomial optimization problem in the presence of multiuser interference (MUI), it is not a convex problem in general. Several optimal solutions proposed in the literature have exponential computational complexity, which is hard to implement for practice. We propose an iterative water-filling algorithm that takes advantage of the classical simple water-filling principle. The proposed algorithm reduces significantly the computational complexity compared with the methods in the literature only with a negligible performance degradation. In addition, the generalized eigenvalue technique for beamforming design is utilized in this paper for minimizing MUI, the number of users and the number of antennas of each user can be arbitrary. Simulations show that the sum rate of the proposed method is close to the sum capacity of the MU-MIMO broadcast channel, especially in low signal-to-noise ratio (SNR) region.","PeriodicalId":210993,"journal":{"name":"2013 IEEE 24th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC)","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132459802","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-12-11DOI: 10.1109/PIMRC.2013.6666477
R. Mesleh, S. Ikki
In this paper, spatial modulation (SM) is considered in a cooperative communication system and the effect of imperfect channel estimation on the overall system performance is analyzed. SM is a multiple-input multiple-output (MIMO) technique that considers the multiple transmit antennas as an added constellation points and utilizes them to boost the spectral efficiency. In our analysis, a wireless communication system, where a source communicating with a destination through a direct link and multiple decode and forward (DF) relays, is considered. Imperfect channel knowledge is assumed at each relay and at the destination node. In cooperative mode, only the relays that correctly decode the source signal forward the decoded message to the destination. A closed form expression of the pair wise error probability (PEP) is obtained for a system consisting of two transmit antennas, multiple DF relays and single receive antenna and a tight upper bound is given for the average error probability. As well, asymptotic expression for the PEP at high signal to noise ratio (SNR) is derived.
{"title":"Analysis of cooperative communication spatial modulation with imperfect channel estimation","authors":"R. Mesleh, S. Ikki","doi":"10.1109/PIMRC.2013.6666477","DOIUrl":"https://doi.org/10.1109/PIMRC.2013.6666477","url":null,"abstract":"In this paper, spatial modulation (SM) is considered in a cooperative communication system and the effect of imperfect channel estimation on the overall system performance is analyzed. SM is a multiple-input multiple-output (MIMO) technique that considers the multiple transmit antennas as an added constellation points and utilizes them to boost the spectral efficiency. In our analysis, a wireless communication system, where a source communicating with a destination through a direct link and multiple decode and forward (DF) relays, is considered. Imperfect channel knowledge is assumed at each relay and at the destination node. In cooperative mode, only the relays that correctly decode the source signal forward the decoded message to the destination. A closed form expression of the pair wise error probability (PEP) is obtained for a system consisting of two transmit antennas, multiple DF relays and single receive antenna and a tight upper bound is given for the average error probability. As well, asymptotic expression for the PEP at high signal to noise ratio (SNR) is derived.","PeriodicalId":210993,"journal":{"name":"2013 IEEE 24th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC)","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121034269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-12-11DOI: 10.1109/PIMRC.2013.6666714
Qing Huang, Yingmin Wang
In this paper, we study the two-way relay channel (TWRC) with multi-user (MU), each of which exchanges information with its partners via a common access relay. All users are divided into two groups. Every user exchanges messages with each user in the other group. The two communication terminals use different modulation schemes. We term this system an asymmetric multi-pair two-way relay X channel (TWRXC), in which signal space alignment for network coding (SSA-NC) and network-coding-based interference nulling beamforming are employed. Considering modulation schemes of two communication terminals are different, we propose a novel reencode function at the relay and decoding rule at the user side to realize the reliable communication. The bit error rates (BERs) of the proposed system is derived. Monte Carlo simulations show that the proposed scheme can improve system performance significantly.
{"title":"Signal space alignment for asymmetric multi-pair two-way relay X channels","authors":"Qing Huang, Yingmin Wang","doi":"10.1109/PIMRC.2013.6666714","DOIUrl":"https://doi.org/10.1109/PIMRC.2013.6666714","url":null,"abstract":"In this paper, we study the two-way relay channel (TWRC) with multi-user (MU), each of which exchanges information with its partners via a common access relay. All users are divided into two groups. Every user exchanges messages with each user in the other group. The two communication terminals use different modulation schemes. We term this system an asymmetric multi-pair two-way relay X channel (TWRXC), in which signal space alignment for network coding (SSA-NC) and network-coding-based interference nulling beamforming are employed. Considering modulation schemes of two communication terminals are different, we propose a novel reencode function at the relay and decoding rule at the user side to realize the reliable communication. The bit error rates (BERs) of the proposed system is derived. Monte Carlo simulations show that the proposed scheme can improve system performance significantly.","PeriodicalId":210993,"journal":{"name":"2013 IEEE 24th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC)","volume":"238 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126812944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-12-11DOI: 10.1109/PIMRC.2013.6666586
A. Salhab, S. Zummo
In this paper, we evaluate the interference effect on the performance of incremental decode-and-forward (DF) relay systems with a low-complexity relaying protocols and interference at the relays and destination. These protocols are based on the switch-and-examine diversity combining (SEC) and switch-and-examine diversity combining with post-examining selection (SECps) techniques. Based on the relaying criterion, the first checked relay whose second hop signal-to-noise ratio (SNR) satisfies a predetermined switching threshold is asked to forward the source message to destination only if the direct link is in outage. Closed-form expression is derived for the end-to-end (e2e) outage probability assuming Rayleigh fading channels. Also, the system performance is studied at high SNR regime for the two relaying protocols where the diversity order and coding gain are derived and analyzed. We assume that maximal-ratio combining (MRC) is used at the destination to combine the signal through the relay with that on the direct link. Monte-Carlo simulations are provided to validate the achieved analytical results. Findings illustrate that despite the presence of interference, the system still achieves performance gain and that the outage probability decreases when the number of relays increases, especially, in the range of SNR values that are comparable to switching threshold. Also, results show the effectiveness of the SEC and SECps relaying protocols in reducing the system complexity compared to the existing protocols as the opportunistic relaying.
{"title":"A low-complexity relaying protocols for incremental DF relay systems with co-channel interference","authors":"A. Salhab, S. Zummo","doi":"10.1109/PIMRC.2013.6666586","DOIUrl":"https://doi.org/10.1109/PIMRC.2013.6666586","url":null,"abstract":"In this paper, we evaluate the interference effect on the performance of incremental decode-and-forward (DF) relay systems with a low-complexity relaying protocols and interference at the relays and destination. These protocols are based on the switch-and-examine diversity combining (SEC) and switch-and-examine diversity combining with post-examining selection (SECps) techniques. Based on the relaying criterion, the first checked relay whose second hop signal-to-noise ratio (SNR) satisfies a predetermined switching threshold is asked to forward the source message to destination only if the direct link is in outage. Closed-form expression is derived for the end-to-end (e2e) outage probability assuming Rayleigh fading channels. Also, the system performance is studied at high SNR regime for the two relaying protocols where the diversity order and coding gain are derived and analyzed. We assume that maximal-ratio combining (MRC) is used at the destination to combine the signal through the relay with that on the direct link. Monte-Carlo simulations are provided to validate the achieved analytical results. Findings illustrate that despite the presence of interference, the system still achieves performance gain and that the outage probability decreases when the number of relays increases, especially, in the range of SNR values that are comparable to switching threshold. Also, results show the effectiveness of the SEC and SECps relaying protocols in reducing the system complexity compared to the existing protocols as the opportunistic relaying.","PeriodicalId":210993,"journal":{"name":"2013 IEEE 24th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC)","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115282783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-12-11DOI: 10.1109/PIMRC.2013.6666431
Shady S. Khalifa, H. Hamza, K. El-Sayed
Self-adaptation is a key factor for the future evolution of mobile networks due to their increasing complexity and required management efforts. In this paper, we propose an autonomous self-adaptive scheme based on Harmony Search (HS) Algorithm for radio resource management and interference coordination. One of the main strong points of the proposed scheme is that the computations are independent on the number of users and cells in the network. This allows the proposed scheme to adapt to networks of any size and with an arbitrary number of users. The proposed scheme is based on the continuous “selfish” minimization of the violations to the user's rate requirements. Each cell operates individually leading to the decomposition of the complex multi-cell allocation problem into a set of distributed simpler single-cell optimization problems. No a-priori frequency planning and/or explicit inter-cell coordination is required. The scheme also achieves a level of altruism by restricting the use of channels satisfying certain rate criterion to allow other cells to utilize them without being affected by interference. Through extensive simulations, we demonstrate that the proposed scheme leads the network to self-adapt into efficient frequency reuse patterns that provides substantial performance improvements to edge users without penalizing other users. We also conducted sensitivity analysis that showed that the values of HS parameters have minimum effect on the scheme performance.
{"title":"Self-adaptive inter-cell interference coordination scheme for LTE systems","authors":"Shady S. Khalifa, H. Hamza, K. El-Sayed","doi":"10.1109/PIMRC.2013.6666431","DOIUrl":"https://doi.org/10.1109/PIMRC.2013.6666431","url":null,"abstract":"Self-adaptation is a key factor for the future evolution of mobile networks due to their increasing complexity and required management efforts. In this paper, we propose an autonomous self-adaptive scheme based on Harmony Search (HS) Algorithm for radio resource management and interference coordination. One of the main strong points of the proposed scheme is that the computations are independent on the number of users and cells in the network. This allows the proposed scheme to adapt to networks of any size and with an arbitrary number of users. The proposed scheme is based on the continuous “selfish” minimization of the violations to the user's rate requirements. Each cell operates individually leading to the decomposition of the complex multi-cell allocation problem into a set of distributed simpler single-cell optimization problems. No a-priori frequency planning and/or explicit inter-cell coordination is required. The scheme also achieves a level of altruism by restricting the use of channels satisfying certain rate criterion to allow other cells to utilize them without being affected by interference. Through extensive simulations, we demonstrate that the proposed scheme leads the network to self-adapt into efficient frequency reuse patterns that provides substantial performance improvements to edge users without penalizing other users. We also conducted sensitivity analysis that showed that the values of HS parameters have minimum effect on the scheme performance.","PeriodicalId":210993,"journal":{"name":"2013 IEEE 24th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115203461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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