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Massive multiple-input multiple-output (MIMO) is an emerging technology for future wireless networks, scaling up conventional MIMO to an unprecedented number of antennas at base stations. Such a large antenna array has the potential to make the system achieve high channel capacity and spectral efficiency, but it also leads to high cost in terms of hardware complexity. In this paper, we consider a...
In this paper, the measurement results of field experiments for correlation reduction precoding with a repetition code in an overloaded MIMO systems are presented. Measurements are conducted in three propagation conditions that are line-of-sight (LOS), non-line-of- sight (NLOS), and a mobile environment. Numerical results obtained through the measurements show that amplitude shift and phase rotation...
In this paper, we study upper bounds on the sum capacity of the downlink multicell processing model with finite backhaul capacity for the simple case of 2 base stations and 2 mobile users. It is modeled as a two-user multiple access diamond channel. It consists of a first hop from the central processor to the base stations via orthogonal links of finite capacity, and the second hop from the base stations...
We derive a closed-form expression for the throughput in the uplink of a cooperative massive MIMO system. We consider a network where a cluster of base stations co-operate to detect signals from mobiles using a linear minimum-mean-square error receiver. A user-centric clustering approach is assumed, where the cluster that detects the signals from each mobile is composed of the K base stations that...
Millimeter wave (mmWave) is a promising carrier frequency to implement massive MIMO networks. Due to the limitation on the number of RF chains and the channel sparsity in clusters, mmWave massive MIMO networks may apply a beam sweep method to estimate the channel in the angular domain. We propose a stochastic geometry framework to study the performance of beam sweep in the uplink. Based on the framework,...
The evolving 5G standards promise green communications with enhanced data services and significant link reliability. Massive multi input multi output (MIMO) techniques are the driving force behind green communications, since they provide better energy efficiency with reduced transmit power. The massive data generated from such mobile communication systems, is a rich data source of great value. Procuring...
One of the main areas of research for the next generation of mobile communications (5G) is the concept of Massive MIMO, which implies using base stations that employ a considerably larger number of antennas than the classic MIMO systems (tens or even hundreds of antennas). The challenges become increasingly difficult when it comes to dealing with multiple mobile stations (MU-MIMO system) sharing the...
The demand for electrical power is growing tremendously, which poses grand challenges to modern energy systems. The telecommunications industry takes a significant part in the global power consumption. In this work we introduce the multi-beam zooming concept as a new perspective to the energy-efficient 5G network, where the multi-beam zooming technique incorporates the beam zooming and multi-beam...
With the rapid growth of global mobile data transmission, the conventional multiple-input multiple-output (MIMO) systems are not able to accommodate the increasing data demand. The massive MIMO has been proposed as one of the key technologies for the next generation wireless communication systems. Compared to the conventional MIMO systems, massive MIMO systems are advantaged in energy and spectral...
This paper considers millimeter-wave access network systems using a hybrid beamforming structure, which is a combination of digital and analog beamformers. To multiplex mobile stations in the frequency domain along with the space and time domain improves a system capacity for the following reasons: it exploits frequency diversity, accommodates mobile stations that can only use a limited bandwidth...
Analog network coding has been successfully employed in conventional two way relaying systems. However, analog two way relaying is successful when the two sender and destination nodes are symmetric. In practical cellular-based mobile communication systems of the likes of Long Term Evolution (LTE), the system is composed of several powerful base-stations and low power users' equipment. Applying classical...
Long Term Evolution Advanced (LTE-Advanced) is the next step in LTE evolution and allows operators to improve network performance and service capabilities through smooth deployment of new techniques and technologies. LTE-Advanced uses some new features on top of the existing LTE standards and protocols to provide better user experience and higher throughputs. Some of the most significant features...
In this paper, we model a Virtual MIMO system using a game-theoretic approach. We are interested in the uplink, considering a non-coopertive game, where each user try to satisfy a quality of service. The uplink of a direct-sequence code division multiple access (DS-CDMA) data network is considered and a non-cooperative game is proposed in which users are allowed to choose their uplink receivers as...
This paper studies an uplink massive MIMO system that employs zero-forcing (ZF) receiver and pilot reuse. Although with infinity number of antennas it has been shown that maximum ratio combining (MRC) attains the same throughput as ZF, we find that for antenna number as large as 100, ZF attains significant throughput gain over MRC. A tight lower bound is derived for cell throughput attained by ZF,...
Spatial multiplexing using Massive MIMO has been shown to have very promising properties, including large gains in spectral efficiency and several orders of magnitude lower transmit power, as compared to today's access schemes. The properties of massive MIMO have been studied mostly for theoretical channels with independent and identically distributed (i.i.d.) complex Gaussian coefficients. To efficiently...
Cellular mobile communication systems reuse the same frequency channel in geographically distant areas to improve the spectrum efficiency. However, co-channel interference among cells remains a critical issue. Mitigating co-channel interference leads to a further improvement in spectrum efficiency. To reduce the co-channel interference we proposed vertical plane beam control using precoding and cooperative...
Modeling MIMO time-variant channels as real world of wave propagation environments dictates, becomes crucial in wireless communication where an accurate knowledge about the channel state information is expected to be available for the transceivers. However instead of having unreliable and inefficiency instantaneous channel state information (CSI) where the feedback mechanisms often generate a delay...
It is widely believed that cooperation among base stations can be employed to enhance the interference mitigation capability of base station receivers in cellular networks. Among the base station cooperation schemes that have been proposed to address the uplink interference problem, two promising ones are 1) Joint Multi-Cell MMSE Processing also referred to as Network MIMO; and 2) Multi-Cell Successive...
Recently, a distributed architecture for base stations was proposed. In this new configuration, the base station is separated into two parts: the radio frequency part near the antenna and the baseband processing unit. The interface connection between them is ensured by an optical fiber. In this paper, we present the ongoing works on standardization of the optical interface and the proposed solutions...
MIMO and space-time coding (STC) as signal processing form a system which highly leads to perform the reliability and the capacity of the link of communications. This is achievable if the channel state information (CST) is perfectly known at the transceiver. Often the transceiver is not able to acquire the instantaneous knowledge of the channel state. Yet it can have a partial knowledge or estimation,...
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