Base station

About: Base station is a research topic. Over the lifetime, 85883 publications have been published within this topic receiving 1019303 citations. The topic is also known as: Mobile phone base stations & BS.

Power and spreading factor control in low power wide area networks

Abstract: Low power wide area networks are gaining interest to connect thousands of nodes to the internet of things However, because the link budget in these networks is huge, nodes suffer from a near-far effect Nodes far from the base station cannot send to the base station succesfully when closer nodes are transmitting, causing destructive collisions LoRa, the considered technology in this paper, is a spread spectrum technology It is known that spread spectrum is also sensitive to this effect This paper presents a scheme to efficiently optimize the packet error rate fairness inside a LoRaWAN cell This is achieved by optimizing the power and spreading factor for each node while avoiding near-far problems by allocating distant users to different channels Simulations show that the packet error rate can be decreased up to 50% for edge nodes in a moderate contention scenario where 1 node per 1000m2 transmits every 10 minutes

Empowering Low-Power Wide Area Networks in Urban Settings

Abstract: Low-Power Wide Area Networks (LP-WANs) are an attractive emerging platform to connect the Internet-of-things. LP-WANs enable low-cost devices with a 10-year battery to communicate at few kbps to a base station, kilometers away. But deploying LP-WANs in large urban environments is challenging, given the sheer density of nodes that causes interference, coupled with attenuation from buildings that limits signal range. Yet, state-of-the-art techniques to address these limitations demand inordinate hardware complexity at the base stations or clients, increasing their size and cost.This paper presents Choir, a system that overcomes challenges pertaining to density and range of urban LP-WANs despite the limited capabilities of base station and client hardware. First, Choir proposes a novel technique that aims to disentangle and decode large numbers of interfering transmissions at a simple, single-antenna LP-WAN base station. It does so, perhaps counter-intuitively, by taking the hardware imperfections of low-cost LP-WAN clients to its advantage. Second, Choir exploits the correlation of sensed data collected by LP-WAN nodes to collaboratively reach a faraway base station, even if individual clients are beyond its range. We implement and evaluate Choir on USRP N210 base stations serving a 10 square kilometer area surrounding Carnegie Mellon University campus. Our results reveal that Choir improves network throughput of commodity LP-WAN clients by 6.84 x and expands communication range by 2.65 x.

Power control device and method for controlling a reverse link common channel in a CDMA communication system

Abstract: A common power control channel transmission device for a base station in a CDMA communication system is provided having a selector for receiving power control commands to be transmitted to multiple subscribers and multiplexing the received power control commands; and a spreading modulator for spreading an output of the selector by multiplying the output of the selector by a spreading sequence. The common power control channel transmission device can be used to control power of a reverse link common channel. For the power control of the reverse link common channel, the base station receives a signal from a mobile station via the reverse link common channel, and transmits to the mobile station a power control command for controlling a transmission power of the reverse link common channel according to a measured strength of the received signal.

Evolution towards fifth generation (5G) wireless networks: Current trends and challenges in the deployment of millimetre wave, massive MIMO, and small cells

Abstract: The exponential increase in mobile data traffic is considered to be a critical driver towards the new era, or 5G, of mobile wireless networks. 5G will require a paradigm shift that includes very high carrier frequency spectra with massive bandwidths, extreme base station densities, and unprecedented numbers of antennas to support the enormous increase in the volume of traffic. This paper discusses several design choices, features, and technical challenges that illustrate potential research topics and challenges for the future generation of mobile networks. This article does not provide a final solution but highlights the most promising lines of research from the recent literature in common directions for the 5G project. The potential physical layer technologies that are considered for future wireless communications include spatial multiplexing using massive multi-user multiple-input multiple-output (MIMO) techniques with millimetre-waves (mm-waves) in small cell geometries. These technologies are discussed in detail along with the areas for future research.

Wireless communication system and method using multiple antennas

Abstract: A wireless communication system, and method using multiple antennas, includes a base station that applies predetermined weight vectors to multi-user signals and transmits the multi-user signals through a plurality of transmission antennas, and a plurality of mobile stations that receive and process the multi-user signals, wherein each mobile station includes a signal reception unit that processes the multi-user signals, and a feedback signal generation unit that estimates channel characteristics, over which the multi-user signals have been transmitted, from the multi-user signals, classifies a plurality of weight vectors to be applied to the estimated channel characteristics into a plurality of sets such that vectors orthogonal to one another are classified into a single set, selects a set maximizing a transmission capacity from among the classified sets, and feeds back weight indexes of weight vectors included in the selected set and weighted channel information to the base station.