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Enhanced C-V2X Mode-4 Subchannel Selection [article]

Luis F. Abanto-Leon, Arie Koppelaar, Sonia Heemstra de Groot
2018 arXiv   pre-print
Let s (f,k) denote the subchannel in sub-band f (for f = 1, 2, . . . , F ) and subframe k (for k = 1, 2, . . . , 100) as depicted inFig. 1.  ...  ε (n,f,k) i = 10 l=1 α l −1 10 l=1 α l ε (n−l,f,k) i , (2) where α ≤ 1 is an exponential weighting factor.  ... 
arXiv:1807.04819v1 fatcat:fkxje7cgwbd5dj2udpndxtttmi

TDOA-based Localization via Stochastic Gradient Descent Variants [article]

Luis F. Abanto-Leon, Arie Koppelaar, Sonia Heemstra de Groot
2018 arXiv   pre-print
Source localization is of pivotal importance in several areas such as wireless sensor networks and Internet of Things (IoT), where the location information can be used for a variety of purposes, e.g. surveillance, monitoring, tracking, etc. Time Difference of Arrival (TDOA) is one of the well-known localization approaches where the source broadcasts a signal and a number of receivers record the arriving time of the transmitted signal. By means of computing the time difference from various
more » ... from various receivers, the source location can be estimated. On the other hand, in the recent few years novel optimization algorithms have appeared in the literature for (i) processing big data and for (ii) training deep neural networks. Most of these techniques are enhanced variants of the classical stochastic gradient descent (SGD) but with additional features that promote faster convergence. In this paper, we compare the performance of the classical SGD with the novel techniques mentioned above. In addition, we propose an optimization procedure called RMSProp+AF, which is based on RMSProp algorithm but with the advantage of incorporating adaptation of the decaying factor. We show through simulations that all of these techniques---which are commonly used in the machine learning domain---can also be successfully applied to signal processing problems and are capable of attaining improved convergence and stability. Finally, it is also shown through simulations that the proposed method can outperform other competing approaches as both its convergence and stability are superior.
arXiv:1807.04824v1 fatcat:snlsizk5ovacdjz2ueqemizioe

Poster: Resource Allocation with Conflict Resolution for Vehicular Sidelink Broadcast Communications [article]

Luis F. Abanto-Leon, Arie Koppelaar, Sonia Heemstra de Groot
2018 arXiv   pre-print
In this paper we present a graph-based resource allocation scheme for sidelink broadcast V2V communications. Harnessing available information on geographical position of vehicles and spectrum resources utilization, eNodeBs are capable of allotting the same set of sidelink resources to different vehicles distributed among several communications clusters. Within a communications cluster, it is crucial to prevent time-domain allocation conflicts since vehicles cannot transmit and receive
more » ... d receive simultaneously, i.e., they must transmit in orthogonal time resources. In this research, we present a solution based on a bipartite graph, where vehicles and spectrum resources are represented by vertices whereas the edges represent the achievable rate in each resource based on the SINR that each vehicle perceives. The aforementioned time orthogonality constraint can be approached by aggregating conflicting vertices into macro-vertices which, in addition, reduces the search complexity. We show mathematically and through simulations that the proposed approach yields an optimal solution. In addition, we provide simulations showing that the proposed method outperforms other competing approaches, specially in scenarios with high vehicular density.
arXiv:1805.08068v1 fatcat:ua45hmbxlzbdjaw7axyyhypa3u

Impact of Quantized Side Information on Subchannel Scheduling for Cellular V2X [article]

Luis F. Abanto-Leon, Arie Koppelaar, Sonia Heemstra de Groot
2018 arXiv   pre-print
In Release 14, 3GPP completed a first version of cellular vehicle--to--everything (C-V2X) communications wherein two modalities were introduced. One of these schemes, known as mode-3, requires support from eNodeBs in order to realize subchannel scheduling. This paper discusses a graph theoretical approach for semi-persistent scheduling (SPS) in mode-3 harnessing a sensing mechanism whereby vehicles can monitor signal--to--interference--plus--noise ratio (SINR) levels across sidelink
more » ... idelink subchannels. eNodeBs request such measurements from vehicles and utilize them to accomplish suitable subchannel assignments. However, since SINR values---herein also referred to as side information---span a wide range, quantization is required. We conclude that 3 bits per vehicle every 100 ms can provide sufficient granularity to maintain appropriate performance without severe degradation. Furthermore, the proposed algorithm is compared against pseudo-random and greedy SPS algorithms.
arXiv:1807.04830v1 fatcat:jamhbo27dvgrraxukymloh7dku

Subchannel Allocation for Vehicle-to-Vehicle Broadcast Communications in Mode-3 [article]

Luis F. Abanto-Leon, Arie Koppelaar, Sonia Heemstra de Groot
2018 arXiv   pre-print
Conversely to mainstream cellular networks where uplink / downlink data traffic is centrally managed by eNodeBs, in vehicle-to-vehicle (V2V) broadcast communications mode-3 eNodeBs engage solely in subchannel assignment but ultimately do not intervene in data traffic control. Accordingly, vehicles communicate directly with their counterparts utilizing the allotted subchannels. Due to its loosely controlled one-to-all nature, V2V mode-3 is advantageous for time-critical applications.
more » ... ations. Nevertheless, it is imperative that the assignment of subchannels is accomplished without conflicts while at the same time satisfying quality of service (QoS) requirements. To the best of our knowledge, there exists no unified framework for V2V mode-3 that contemplates both prevention of allocation conflicts and fulfillment of QoS. Thus, four types of conditions that are of forceful character for attaining QoS-aware conflict-free allocations have been identified: (i) assure differentiated QoS per vehicle, (ii) preclude intra-cluster subframe conflicts, (iii) secure minimal time dispersion of allotted subchannels and (iv) forestall one-hop inter-cluster subchannel conflicts. Such conditions have been systematized and merged in an holistic manner allowing non-complex manipulation to perform subchannel allocation optimization. In addition, we propose a surrogate relaxation of the problem that does not affect optimality provided that certain requisites are satisfied.
arXiv:1805.07003v1 fatcat:aq2rgf2vvfbt5ib6vadvojiife

Graph-Based Resource Allocation with Conflict Avoidance for V2V Broadcast Communications [article]

Luis F. Abanto-Leon, Arie Koppelaar, Sonia Heemstra de Groot
2018 arXiv   pre-print
In this paper we present a graph-based resource allocation scheme for sidelink broadcast vehicle-to-vehicle (V2V) communications. Harnessing available information on the geographical position of vehicles and spectrum resources utilization, eNodeBs are capable of allotting the same set of sidelink resources to several different vehicles in order for them to broadcast their signals. Hence, vehicles sharing the same resources would ideally be in different communications clusters for the
more » ... for the interference level-generated due to resource repurposing-to be maintained under control. Within a communications cluster, it is crucial that vehicles transmit in orthogonal time resources to prevent conflicts as vehicles-with half-duplex radio interfaces--cannot transmit and receive simultaneously. In this research, we have envisaged a solution based on a bipartite graph, where vehicles and spectrum resources are represented by vertices whereas the edges represent the achievable rate in each resource based on the signal-to-interference-plus-noise ratio (SINR) that vehicles perceive. The aforementioned constraint on time orthogonality of allocated resources can be approached by aggregating conflicting vertices into macro-vertices which, in addition, narrows the search space yielding a solution with computational complexity equivalent to the conventional graph matching problem. We show mathematically and through simulations that the proposed approach yields an optimal solution. In addition, we provide simulations showing that the proposed method outperforms other competing approaches, specially in scenarios with high vehicular density.
arXiv:1805.06550v1 fatcat:p6k4gijfxvc7zadxry2q7qi27y

Parallel and Successive Resource Allocation for V2V Communications in Overlapping Clusters [article]

Luis F. Abanto-Leon, Arie Koppelaar, Sonia Heemstra de Groot
2018 arXiv   pre-print
The 3rd Generation Partnership Project (3GPP) has introduced in Rel. 14 a novel technology referred to as vehicle--to--vehicle (V2V) mode-3. Under this scheme, the eNodeB assists in the resource allocation process allotting sidelink subchannels to vehicles. Thereupon, vehicles transmit their signals in a broadcast manner without the intervention of the former one. eNodeBs will thereby play a determinative role in the assignment of subchannels as they can effectively manage V2V traffic and
more » ... V traffic and prevent allocation conflicts. The latter is a crucial aspect to be enforced in order for the signals to be received reliably by other vehicles. To this purpose, we propose two resource allocation schemes namely bipartite graph matching-based successive allocation (BGM-SA) and bipartite graph matching-based parallel allocation (BGM-PA) which are suboptimal approaches with lesser complexity than exhaustive search. Both schemes incorporate constraints to prevent allocation conflicts from emerging. In this research, we consider overlapping clusters only, which could be formed at intersections or merging highways. We show through simulations that BGM-SA can attain near-optimal performance whereas BGM-PA is subpar but less complex. Additionally, since BGM-PA is based on inter-cluster vehicle pre-grouping, we explore different metrics that could effectively portray the overall channel conditions of pre-grouped vehicles. This is of course not optimal in terms of maximizing the system capacity---since the allocation process would be based on simplified surrogate information---but it reduces the computational complexity.
arXiv:1805.07012v1 fatcat:guh6x3haancerfhelh4rsefsba

Complexity-Adjustable SC Decoding of Polar Codes for Energy Consumption Reduction [article]

Haotian Zheng, Bin Chen, Luis F. Abanto-Leon, Zizheng Cao, Ton Koonen
2019 arXiv   pre-print
Luis F.  ...  F.  ... 
arXiv:1912.07649v1 fatcat:7axwp3yvana3hde7kmm7xq42xm

Decentralized Subchannel Scheduling for C-V2X Mode-4: A Non-Standard Configuration for CAM Retransmissions [article]

Luis F. Abanto-Leon
2019 arXiv   pre-print
Thus, S (f ) = {s (f,1) , . . . , s (f,100) } represents the complete set of subchannels in sub-band f .  ...  Let s (f,k) denote the subchannel in sub-band f (for f = 1, 2, . . . , F ) and subframe k (for k = 1, 2, . . . , 100) as depicted in Fig. 1 .  ... 
arXiv:1912.13137v1 fatcat:3jwcpvxdmbfonm6ocdj256spwu

Network-Assisted Resource Allocation with Quality and Conflict Constraints for V2V Communications [article]

Luis F. Abanto-Leon, Arie Koppelaar, Sonia Heemstra de Groot
2018 arXiv   pre-print
The 3rd Generation Partnership Project (3GPP) has recently established in Rel. 14 a network-assisted resource allocation scheme for vehicular broadcast communications. Such novel paradigm is known as vehicle--to--vehicle (V2V) mode-3 and consists in eNodeBs engaging only in the distribution of sidelink subchannels among vehicles in coverage. Thereupon, without further intervention of the former, vehicles will broadcast their respective signals directly to their counterparts. Because the
more » ... Because the allotment of subchannels takes place intermittently to reduce signaling, it must primarily be conflict-free in order not to jeopardize the reception of signals. We have identified four pivotal types of allocation requirements that must be guaranteed: one quality of service (QoS) requirement and three conflict conditions which must be precluded in order to preserve reception reliability. The underlying problem is formulated as a maximization of the system sum-capacity with four types of constraints that must be enforced. In addition, we propose a three-stage suboptimal approach that is cast as multiple independent knapsack problems (MIKPs). We compare the two approaches through simulations and show that the latter formulation can attain acceptable performance at lesser complexity.
arXiv:1807.04829v1 fatcat:qcweszfku5egjpeoh66kskvmbu

Poster Abstract: Hierarchical Subchannel Allocation for Mode-3 Vehicle-to-Vehicle Sidelink Communications [article]

Luis F. Abanto-Leon, Arie Koppelaar, Sonia Heemstra de Groot
2018 arXiv   pre-print
In V2V Mode-3, eNodeBs assign subchannels to vehicles in order for them to periodically broadcast CAM messages b2. A crucial aspect is to ensure that vehicles in the same cluster will broadcast in orthogonal time subchannels[A subchannel is a time-frequency resource chunk capable of sufficiently conveying a CAM message.] to avoid conflicts. In general, resource/subchannel allocation problems can be represented as weighted bipartite graphs. However, in this scenario there is an additional time
more » ... n additional time orthogonality constraint which cannot be straightforwardly handled by conventional graph matching methods b3. Thus, in our approach the mentioned constraint has been taken into account. We also perform the allocation task in a sequential manner based on the constrainedness of each cluster. To illustrate the gist of the problem, in Fig. 1 we show two partially overlapping clusters where a conflict between vehicles V_8 and V_10 is generated as the allotted subchannels are in the same subframe.
arXiv:1807.05929v1 fatcat:qtt3qvwjejf4dgjxuvukzu52te

Hybrid Precoding for Multi-Group Multicasting in mmWave Systems [article]

Luis F. Abanto-Leon, Matthias Hollick, Gek Hong Sim
2020 arXiv   pre-print
3b) w k 2 2 = P max rx , (3c) F 2 F = N RF tx , (3d) [F] q,r ∈ F , q ∈ Q, r ∈ R, ∀k ∈ G i , i ∈ I, (3e) where (3a) targets the minimization of the transmit power.  ...  j 2 + σ 2 w k 2 2 ≥ γ i , (4b) w k 2 2 = P max rx , (4c) F 2 F = N RF tx , (4d) [F] q,r ∈ F , (4e) x k ≥ 0, q ∈ Q, r ∈ R, ∀k ∈ G i , i ∈ I. (4f) Each x k ∈ R + penalizes the objective function (with a  ... 
arXiv:1908.02678v2 fatcat:xzrymkj3ebgqfin4vps6goynlq

Poster

Luis F. Abanto-Leon, Arie Koppelaar, Sonia Heemstra de Groot
2017 Proceedings of the 23rd Annual International Conference on Mobile Computing and Networking - MobiCom '17  
Poster: Resource Allocation with Conflict Resolution for Vehicular Sidelink Broadcast Communications Luis F.  ...  Abanto-Leon ABSTRACT In this paper we present a graph-based resource allocation scheme for sidelink broadcast V2V communications.  ... 
doi:10.1145/3117811.3131260 dblp:conf/mobicom/Abanto-LeonKG17 fatcat:rg3vlqkcijh4reb74r4relxk5m

Enhanced C-V2X Mode-4 Subchannel Selection

Luis F. Abanto-Leon, Arie Koppelaar, Sonia Heemstra de Groot
2018 2018 IEEE 88th Vehicular Technology Conference (VTC-Fall)  
Let s (f,k) denote the subchannel in sub-band f (for f = 1, 2, . . . , F ) and subframe k (for k = 1, 2, . . . , 100) as depicted inFig. 1.  ...  ε (n,f,k) i = 10 l=1 α l −1 10 l=1 α l ε (n−l,f,k) i , (2) where α ≤ 1 is an exponential weighting factor.  ... 
doi:10.1109/vtcfall.2018.8690754 dblp:conf/vtc/Abanto-LeonKG18b fatcat:yxoc665levhx5hukdbpuyropkq

BEAMWAVE: Cross-Layer Beamforming and Scheduling for Superimposed Transmissions in Industrial IoT mmWave Networks [article]

Luis F. Abanto-Leon and Matthias Hollick and Gek Hong Sim
2021 arXiv   pre-print
Thus, θ j,l = ω Hmax 2 F − H j 2 F Hmax 2 F + Hmax 2 F − H l 2 F Hmax 2 F + (1 − ω) Nrx n 1 =1 Nrx n 2 =1 1 N 2 rx |Hj(n1)H H l (n 2 )| H j (n 1 ) 2 H l (n 2 ) 2 , where Hmax 2 F = max j∈K H j 2 F and  ...  Thus, ROOK is defined as θ j,l = ω H j 2 F − H l 2 F H j 2 F + H l 2 F + (1 − ω) Nrx n 1 =1 Nrx n 2 =1 1 N 2 rx |Hj(n1)H H l (n 2 )| H j (n 1 ) 2 H l (n 2 ) 2 with 0 ≤ ω ≤ 1.  ... 
arXiv:2108.04313v1 fatcat:uffbgu2klrazrmrec4atk2yqhm
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