| 1. |
- Durisi, Giuseppe, 1977, et al.
(författare)
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On the multiplexing gain of MIMO Microwave backhaul links affected by Phase Noise
- 2013
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Ingår i: IEEE International Conference on Communications. - 1550-3607. - 9781467331227 ; , s. 3209-3214
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Konferensbidrag (refereegranskat)abstract
- We consider a multiple-input multiple-output (MIMO) AWGN channel affected by phase noise. Focusing on the 2 × 2 case, we show that no MIMO multiplexing gain is to be expected when the phase-noise processes at each antenna are independent, memoryless in time, and with uniform marginal distribution over [0,2π] (strong phase noise), and when the transmit signal is isotropically distributed on the real plane. The scenario of independent phase-noise processes across antennas is relevant for microwave backhaul links operating in the 20–40 GHz range.
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| 2. |
- Mayer, Zoltán, et al.
(författare)
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On the Impact of Backhaul Channel Reliability on Cooperative Wireless Networks
- 2013
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Ingår i: IEEE International Conference on Communications. - 1550-3607. - 9781467331227 ; , s. 5284-5289
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Konferensbidrag (refereegranskat)abstract
- We study the effect of unreliable backhaul links on the performance of Coordinated Multi-Point (CoMP) techniques. CoMP has emerged as a powerful scheme to mitigate co-channel interference. Economically viable deployment of Heterogeneous Networks (HetNets) will require the use of lower-performance backhaul options, e.g. non-line-of-sight microwave links. Motivated by HetNets, a backhauling model is introduced, by assigning Link Failure Probability (LFP) to backhaul links, for the cooperative clusters. In this paper we analyze the centralized and semi-distributed CoMP architectures. We investigate the probability of deficient backhaul links reducing quality of service, by impeding transmission. By valuating the average sum rate of users within a CoMP cluster, we show how backhaul link reliability affects the performance of the cooperative cluster. We conclude, that the performance gains offered by CoMP quickly diminish, as the unreliability of the backhaul links grows.
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| 3. |
- Piemontese, Amina, et al.
(författare)
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Nonbinary Spatially-coupled LDPC Codes on the Binary Erasure Channel
- 2013
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Ingår i: IEEE International Conference on Communications. - 1550-3607. - 9781467331227 ; , s. 3270 - 3274
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Konferensbidrag (refereegranskat)abstract
- We analyze the asymptotic performance of non-binary spatially-coupled low-density parity-check (SC-LDPC) codes built on the general linear group, when the transmission takes place over the binary erasure channel. We propose an efficient method to derive an upper bound to the maximum a posteriori probability (MAP) threshold for nonbinary LDPC codes, and observe that the MAP performance of regular LDPC codes improves with the alphabet size. We then consider nonbinary SC-LDPC codes. We show that the same threshold saturation effect experienced by binary SC-LDPC codes occurs for the nonbinary codes, hence we conjecture that the BP threshold for large termination length approaches the MAP threshold of the underlying regular ensemble.
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| 4. |
- Soleimani-Nasab, Ehsan, 1984, et al.
(författare)
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On the performance of multi-antenna AF relaying systems over Nakagami-m fading channels
- 2013
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Ingår i: IEEE International Conference on Communications. - 1550-3607. - 9781467331227 ; , s. 3041-3046
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Konferensbidrag (refereegranskat)abstract
- We analyze the performance of a dual-hop selection combining amplify-and-forward cooperative system over independent and identically distributed Nakagami-m fading channels, where multiple antennas are deployed in the receive side of relays and the destination. The outage probability, symbol error probability and average channel capacity are derived at arbitrary signal to noise ratios (SNRs). In order to obtain additional physical insights, we derive the above mentioned performance metrics in the high SNR regime; this enables us to parameterize the performance of the system in terms of diversity order and coding gain. Furthermore, some special cases of interest (e.g., Nakagami-0.5 and Rayleigh fading channels) are also studied. It is demonstrated that the analytical expressions, expressed via infinite series, match precisely with the Monte-Carlo simulations using only a small number of terms.
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| 5. |
- Wanlu, Sun, 1986, et al.
(författare)
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On clock offset and skew estimation with exponentially distributed delays
- 2013
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Ingår i: IEEE International Conference on Communications. - 1550-3607. - 9781467331227 ; , s. 1872-1877
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Konferensbidrag (refereegranskat)abstract
- This paper investigates the problem of clock synchronization of nodes in a wireless sensor network based on the two-way timing message exchange mechanism with an unknown deterministic transmission delay and random exponential transmission delays. Without knowing the fixed delay, a novel synchronization scheme is proposed for the linear clock model, which works well in both symmetric and asymmetric links. In the proposed algorithm, the clock skew and offset are estimated by directly utilizing mean square error as the metric to be optimized. This consideration results in significant performance improvements compared to the existing synchronization methods, especially for a small number of observations and large standard deviation of the random delays. © 2013 IEEE.
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| 6. |
- Wymeersch, Henk, 1976, et al.
(författare)
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Comparison of reweighted message passing algorithms for LDPC decoding
- 2013
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Ingår i: IEEE International Conference on Communications (ICC), 2013. - : IEEE. - 1550-3607. - 9781467331227 ; , s. 3264-3269
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Konferensbidrag (refereegranskat)abstract
- Low density parity check (LDPC) codes can be decoded with a variety of decoding algorithms, offering a trade-off in terms of complexity, latency, and performance. We describe seven distinct LDPC decoders and provide a performance comparison for a practical regular LDPC code. Our simulations indicate that the best performance/latency trade-off is achieved by one version ofthe reweighted max-product decoder. When latency is not an issue, the traditional sum-product decoder yields the best performance.
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| 7. |
- Zhang, J., et al.
(författare)
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Effective rate analysis of MISO η-μ Fading channels
- 2013
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Ingår i: IEEE International Conference on Communications. - 1550-3607. - 9781467331227 ; , s. 5840-5844
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Konferensbidrag (refereegranskat)abstract
- In this paper, we analytically investigate the achievable rate of multiple-input single-output (MISO) channels in the presence of delay constraints. In particular, we focus on the so-called effective rate which was recently established as a suitable metric for assessing the impact of delay constraints on the overall performance of communication systems. Yet, most prior relevant works have considered only the typical cases of Rayleigh, Rician and Nakagami-m fading which allow for tractable manipulations. In this paper, we relax this assumption by considering MISO systems over η-μ fading channels. The η-μ distribution has been shown to provide very good fit to experimental data in various propagation environments. New, analytical expressions for the exact effective rate are derived. Moreover, we consider the asymptotically high and low signal-to-noise (SNR) regimes, for which tractable, closed-form effective rate expressions are presented. These results enable us to explicitly investigate the impact of system parameters on the effective rate of MISO η-μ fading channels.
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| 8. |
- Zhang, J., et al.
(författare)
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Gallager's error exponent analysis of STBC systems over η-μ Fading channels
- 2013
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Ingår i: IEEE International Conference on Communications. - 1550-3607. - 9781467331227 ; , s. 5829-5834
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Konferensbidrag (refereegranskat)abstract
- The Gallager's random coding error exponent for space-time block codes (STBC) over multiple-input multiple-output (MIMO) block-fading channels, with Gaussian input distribution, is investigated. Gallager's error exponent can be used to determine the required codeword length to achieve a prescribed error probability at a given rate below the channel capacity. We first provide new, analytical expressions for Gallager's exponent of STBC systems over η-μ fading channels. The Shannon capacity and cutoff rate, which can be directly derived from Gallager's exponent, are further examined. In order to get additional insights, a high signal-to-noise ratio analysis is pursued to investigate the effects of coherence time and codeword length on the error probability. For the sake of completeness, we provide the link to previous known results on Rayleigh and Nakagami-m fading channels.
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| 9. |
- Abu-Shaban, Z., et al.
(författare)
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Near-field Localization with a Reconfigurable Intelligent Surface Acting as Lens
- 2021
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Ingår i: IEEE International Conference on Communications. - 1550-3607. ; June 2021
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Konferensbidrag (refereegranskat)abstract
- Exploiting wavefront curvature enables localization with limited infrastructure and hardware complexity. With the introduction of reconfigurable intelligent surfaces (RISs), new opportunities arise, in particular when the RIS is functioning as a lens receiver. We investigate the localization of a transmitter using a RIS-based lens in close proximity to a single receive antenna element attached to reception radio frequency chain. We perform a Fisher information analysis, evaluate the impact of different lens configurations, and propose a two-stage localization algorithm. Our results indicate that positional beamforming can lead to better performance when a priori location information is available, while random beamforming is preferred when a priori information is lacking. Our simulation results for a moderate size lens operating at 28 GHz showcased that decimeter-level accuracy can be attained within 3 meters to the lens.
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| 10. |
- Ahmad, Suhail, 1992, et al.
(författare)
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Predictive Resource Allocation Evaluation with Real Channel Measurements
- 2017
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Ingår i: IEEE International Conference on Communications. - 1550-3607.
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Konferensbidrag (refereegranskat)abstract
- Mobile services, especially video streaming, has seen a rapid usage increase in recent years. Base stations (BSs) need to employ smarter and efficient resource allocation strategies to maintain high quality of service (QoS) to users at all the times. Predictive resource allocation (PRA), is one such novel scheme, in which BSs seek to anticipate the user demands and offer service to users in advance. As a result, the QoS can be improved, network load can be distributed over time, while at the same time offering efficient utilization of BS power. In location-aware PRA, the BS exploits location information of the users to predict the channel expected variations and adapt the BS resources accordingly. We evaluate PRA strategies based on an empirical study of the radio channel variation from measured location-aided channel radio maps using a smart phone. We observed that gains offered by the PRA scheme are highly dependent on user mobility patterns.
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