### Abstract

Small cell networks have recently been proposed as an important evolution path for the next-generation cellular networks. However, with more and more irregularly deployed base stations (BSs), it is becoming increasingly difficult to quantify the achievable network throughput or energy efficiency. In this paper, we develop an analytical framework for downlink performance evaluation of small cell networks, based on a random spatial network model, where BSs and users are modeled as two independent spatial Poisson point processes. A new simple expression of the outage probability is derived, which is analytically tractable and is especially useful with multi-antenna transmissions. This new result is then applied to evaluate the network throughput and energy efficiency. It is analytically shown that deploying more BSs can always increase the network throughput, but the throughput will scale with the BS density first linearly, then logarithmically, and finally converge to a constant. On the other hand, increasing the number of BS antennas can decrease the outage probability exponentially, thus can always increase the network throughput. However, increasing the BS density or the number of transmit antennas will first increase and then decrease the energy efficiency if the non-transmission power or the circuit power consumption is less than certain thresholds, and the optimal BS density and the optimal number of BS antennas can be found. Otherwise, the energy efficiency will always decrease. Simulation results shall demonstrate that our conclusions based on the random network model are general and also hold in a regular grid-based model.

Original language | English |
---|---|

Article number | 6775036 |

Pages (from-to) | 2505-2517 |

Number of pages | 13 |

Journal | IEEE Transactions on Wireless Communications |

Volume | 13 |

Issue number | 5 |

DOIs | |

Publication status | Published - 2014 |

Externally published | Yes |

### Fingerprint

### Keywords

- cellular networks
- energy efficiency
- network throughput
- outage probability
- Poisson point process
- stochastic geometry

### ASJC Scopus subject areas

- Computer Science Applications
- Applied Mathematics
- Electrical and Electronic Engineering

### Cite this

*IEEE Transactions on Wireless Communications*,

*13*(5), 2505-2517. [6775036]. https://doi.org/10.1109/TWC.2014.031714.131020

**Throughput and energy efficiency analysis of small cell networks with multi-antenna base stations.** / Li, Chang; Zhang, Jun; Letaief, Khaled.

Research output: Contribution to journal › Article

*IEEE Transactions on Wireless Communications*, vol. 13, no. 5, 6775036, pp. 2505-2517. https://doi.org/10.1109/TWC.2014.031714.131020

}

TY - JOUR

T1 - Throughput and energy efficiency analysis of small cell networks with multi-antenna base stations

AU - Li, Chang

AU - Zhang, Jun

AU - Letaief, Khaled

PY - 2014

Y1 - 2014

N2 - Small cell networks have recently been proposed as an important evolution path for the next-generation cellular networks. However, with more and more irregularly deployed base stations (BSs), it is becoming increasingly difficult to quantify the achievable network throughput or energy efficiency. In this paper, we develop an analytical framework for downlink performance evaluation of small cell networks, based on a random spatial network model, where BSs and users are modeled as two independent spatial Poisson point processes. A new simple expression of the outage probability is derived, which is analytically tractable and is especially useful with multi-antenna transmissions. This new result is then applied to evaluate the network throughput and energy efficiency. It is analytically shown that deploying more BSs can always increase the network throughput, but the throughput will scale with the BS density first linearly, then logarithmically, and finally converge to a constant. On the other hand, increasing the number of BS antennas can decrease the outage probability exponentially, thus can always increase the network throughput. However, increasing the BS density or the number of transmit antennas will first increase and then decrease the energy efficiency if the non-transmission power or the circuit power consumption is less than certain thresholds, and the optimal BS density and the optimal number of BS antennas can be found. Otherwise, the energy efficiency will always decrease. Simulation results shall demonstrate that our conclusions based on the random network model are general and also hold in a regular grid-based model.

AB - Small cell networks have recently been proposed as an important evolution path for the next-generation cellular networks. However, with more and more irregularly deployed base stations (BSs), it is becoming increasingly difficult to quantify the achievable network throughput or energy efficiency. In this paper, we develop an analytical framework for downlink performance evaluation of small cell networks, based on a random spatial network model, where BSs and users are modeled as two independent spatial Poisson point processes. A new simple expression of the outage probability is derived, which is analytically tractable and is especially useful with multi-antenna transmissions. This new result is then applied to evaluate the network throughput and energy efficiency. It is analytically shown that deploying more BSs can always increase the network throughput, but the throughput will scale with the BS density first linearly, then logarithmically, and finally converge to a constant. On the other hand, increasing the number of BS antennas can decrease the outage probability exponentially, thus can always increase the network throughput. However, increasing the BS density or the number of transmit antennas will first increase and then decrease the energy efficiency if the non-transmission power or the circuit power consumption is less than certain thresholds, and the optimal BS density and the optimal number of BS antennas can be found. Otherwise, the energy efficiency will always decrease. Simulation results shall demonstrate that our conclusions based on the random network model are general and also hold in a regular grid-based model.

KW - cellular networks

KW - energy efficiency

KW - network throughput

KW - outage probability

KW - Poisson point process

KW - stochastic geometry

UR - http://www.scopus.com/inward/record.url?scp=84901367917&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84901367917&partnerID=8YFLogxK

U2 - 10.1109/TWC.2014.031714.131020

DO - 10.1109/TWC.2014.031714.131020

M3 - Article

AN - SCOPUS:84901367917

VL - 13

SP - 2505

EP - 2517

JO - IEEE Transactions on Wireless Communications

JF - IEEE Transactions on Wireless Communications

SN - 1536-1276

IS - 5

M1 - 6775036

ER -