Analysis of a Frequency-Hopping Millimeter-Wave Cellular Uplink

At millimeter wave (mmWave) frequencies, signals are prone to blocking by objects in the environment, which causes paths to go from line-of-sight (LOS) to non-LOS (NLOS). We consider macrodiversity as a strategy to improve the performance of mmWave cellular systems, where the user attempts to connect with two or more base stations. An accurate analysis of macrodiversity must account for the possibility of correlated blocking, which occurs when a single blockage simultaneously blocks the paths to two base stations. In this paper, we analyze the macrodiverity gain in the presence of correlated random blocking and interference. To do so, we develop a framework to determine distributions for the LOS probability, SNR, and SINR by taking into account correlated blocking. We consider a cellular uplink with both diversity combining and selection combining schemes. We also study the impact of blockage size and blockage density. We show that blocking can be both a blessing and a curse. On the one hand, the signal from the source transmitter could be blocked, and on the other hand, interfering signals tend to also be blocked, which leads to a completely different effect on macrodiversity gains. We also show that the assumption of independent blocking can lead to an incorrect evaluation of macrodiversity gain, as the correlation tends to decrease macrodiversity gain.

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“…See, for instance, [9] for more detail. We may also consider the use of directional antennas, which will control the effect of interference [14].…”

Section: Discussionmentioning

confidence: 99%

The Potential Gains of Macrodiversity in mmWave Cellular Networks with Correlated Blocking

Hriba

Valenti

2019

MILCOM 2019 - 2019 IEEE Military Communications Conference (MILCOM)

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“…See, for instance, [17] for more detail. We may also consider the use of directional antennas, which will control the effect of interference [30].…”

Section: Discussionmentioning

confidence: 99%

Correlated Blocking in mmWave Cellular Networks: Macrodiversity, Outage, and Interference

Hriba

Valenti

2019

Electronics

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In this paper, we provide a comprehensive analysis of macrodiversity for millimeter wave (mmWave) cellular networks. The key issue with mmWave networks is that signals are prone to blocking by objects in the environment, which causes paths to go from line-of-sight (LOS) to non-LOS (NLOS). We identify macrodiversity as an important strategy for mitigating blocking, as with macrodiversity the user will attempt to connect with two or more base stations. Diversity is achieved because if the closest base station is blocked, then the next base station might still be unblocked. However, since it is possible for a single blockage to simultaneously block the paths to two base stations, the issue of correlated blocking must be taken into account by the analysis. Our analysis characterizes the macrodiverity gain in the presence of correlated random blocking and interference. To do so, we develop a framework to determine distributions for the LOS probability, Signal to Noise Ratio (SNR), and Signal to Interference and Noise Ratio (SINR) by taking into account correlated blocking. We validate our framework by comparing our analysis, which models blockages using a random point process, with an analysis that uses real-world data to account for blockage. We consider a cellular uplink with both diversity combining and selection combining schemes. We also study the impact of blockage size and blockage density along with the effect of co-channel interference arising from other cells. We show that the assumption of independent blocking can lead to an incorrect evaluation of macrodiversity gain, as the correlation tends to decrease macrodiversity gain.

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“…Due to the analytical complexity of deriving the CDF of the observed SINR for this case, we assume that no inter-beam interference exists which provides a useful performance bound. One way to achieve this, is by employing antenna arrays at the AP to perform directional beamforming [32]. As a result, the antenna patterns partition the area into M orthogonal sectors, each of density λ/M , and the AP transmits each beam to a pre-assigned sector.…”

Section: Beam Outage Probabilitymentioning

confidence: 99%

A Wireless Powered Feedback Protocol for Opportunistic Beamforming Using Rectenna Arrays

Psomas

Krikidis

2018

IEEE Trans. on Green Commun. Netw.

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This paper proposes an opportunistic beamforming (OBF) protocol with limited feedback in the context of wireless powered communication networks. The terminals are randomly deployed around an access point (AP) and are equipped with multiple antennas as well as a rectenna array to harvest energy. In the OBF scheme, the AP acquires channel related feedback from the network's terminals and allocates the orthonormal beams to the users with the best link. We consider the case, where the feedback is solely powered by energy harvested from electromagnetic radiation. Specifically, each terminal adjusts the length of its feedback based on the amount of harvested energy; when the energy is not sufficient to feed back at least one bit, the terminal is considered to be in outage. We study two fundamental rectenna architectures, the direct-current combiner and the radio-frequency combiner (coherent and non-coherent), as well as a hybrid architecture of these two. Furthermore, to alleviate the doubly near-far problem, we consider a scheme where a terminal adapts the number of rectenna elements according to its distance from the origin. By using higher order statistics and stochastic geometry, the beam outage probability is derived in closed form for all considered architectures and scenarios. Index Terms-Opportunistic beamforming, wireless power transfer, antenna array, stochastic geometry. I. INTRODUCTION Knowledge of channel state information (CSI) in wireless communication networks is crucial for enhancing the information transfer between a receiver and a transmitter. A well-known approach in obtaining CSI at the transmitter is the employment of a feedback mechanism. In this case, the receiver feeds back information to the transmitter regarding its channel and, in turn, the transmitter adapts its operation accordingly based on the acquired knowledge [2]. The study of feedback in communication systems has a rich history, dating back to the time of Shannon [3], and can also be found in recent IEEE standards [4]. Among the numerous communication techniques that exploit the use of feedback, opportunistic communication is characterized for its simplicity as well as efficiency in improving the network's performance. According to this technique, in a point-to-point scenario, the transmitter increases or reduces its power based on whether the C.

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Analysis of a Frequency-Hopping Millimeter-Wave Cellular Uplink

Cited by 27 publications

References 23 publications

The Potential Gains of Macrodiversity in mmWave Cellular Networks with Correlated Blocking

The Potential Gains of Macrodiversity in mmWave Cellular Networks with Correlated Blocking

Correlated Blocking in mmWave Cellular Networks: Macrodiversity, Outage, and Interference

A Wireless Powered Feedback Protocol for Opportunistic Beamforming Using Rectenna Arrays

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