Cache-Enabled HetNets With Millimeter Wave Small Cells

Abstract

In this paper, we consider a novel cache-enabled heterogeneous network (HetNet), where macro base stations (BSs) with traditional sub-6 GHz are overlaid by dense millimeter wave (mmWave) pico BSs. These two-tier BSs, which are modeled as two independent homogeneous Poisson Point Processes, cache multimedia contents following the popularity rank. High-capacity backhauls are utilized between macro BSs and the core server. In contrast to the simplified flat-top antenna pattern analyzed in previous articles, we employ an actual antenna model with the uniform linear array at all mmWave BSs. To evaluate the performance of our system, we introduce two distinctive user association strategies: 1) maximum received power (Max-RP) scheme; and 2) maximum rate (Max-Rate) scheme. With the aid of these two schemes, we deduce new theoretical equations for success probabilities and area spectral efficiencies (ASEs). Considering a special case with practical path loss laws, several closed-form expressions for coverage probabilities are derived to gain several insights. Monte Carlo simulations are presented to verify the analytical conclusions. We show that: 1) the proposed HetNet is an interference-limited system and it outperforms the traditional HetNets in terms of the success probability; 2) there exists an optimal pre-decided rate threshold that contributes to the maximum ASE; and 3) Max-Rate achieves higher success probability and ASE than Max-RP but it needs the extra information of the interference effect.Index Terms-Caching, heterogeneous networks, millimeter wave, stochastic geometry, user association • The success probability and area spectral efficiency (ASE) of our hybrid cache-enabled HetNets are discussed under two user association strategies: 1) Maximum Received Power (Max-RP), where the requesting user

Clustered Millimeter-Wave Networks With Non-Orthogonal Multiple Access

“…Proof: As NLOS interferences are ignored, ρ N (v) should be removed from Lemma 4. Moreover, when α L = 2, ρ L (v) can be simplified by using the similar method as discussed in the Appendix A of [49]. Lastly, utilizing the similar proof method as Lemma 4, the simpler equation than (22) can be expressed in (26).…”

Modeling and Analysis of MmWave V2X Networks With Vehicular Platoon Systems

“…Furthermore, machine learning approaches were introduced in [16] to configure beamforming patterns. Note that the average performance of networks is an important metric for designing new protocols [18]. Although the mentioned results based on measurements or simulations are inspiring, it is not efficient to evaluate the average performance of mmWave V2X networks via the same methods.…”

“…For traditional mmWave networks and vehicular communications, stochastic geometry has already been widely utilized [18,[20][21][22][23][24][25][26][27]. The authors in [20] modeled line-of-sight (LOS) and non-LOS (NLOS) base stations (BSs) as two independent thinning Poisson point processes (PPPs) to evaluate the coverage and rate performance of cellular networks.…”

Coverage Analysis of Integrated Sub-6GHz-mmWave Cellular Networks With Hotspots

“…Under this condition, the signal-to-interferenceplus-noise (SINR) coverage probability with decoupled cell association strategy was studied in [14], and it is observed that extremely high small cell association weight is desirable for mmWave SCells. The authors in [15] analyzed the the performance of catch-enable hybrid heterogeneous networks under the similar deployment settings, where the cached multimedia contents following the popularity rank, and it is shown that the integrated Sub-6GHz and mmWave HetNet is interference-limited and outperforms the traditional HetNet. The hybrid cellular network with ultra high frequency and mmWave BSs were investigated in [16] by using experimental data in a university campus.…”

“…To the authors' knowledge, the existing works that considering integrated Sub-6GHz BSs and mmWave BSs usually model each tier of BSs as a PPP [14], [15], while the studies that consider spatial coupling between BSs and UEs in heterogeneous networks assume the operations on the same frequency band [22]- [24]. Different from previous works, we take both different frequency bands and aforementioned coupling in traffic hotspots into consideration.…”