• Proceedings of the IEEK Conference
• /
• 2003.07a
• /
• pp.210-213
• /
• 2003

This paper presents a beamforming algorithm for the uplink application of a linear array antenna for WCDMA system. A steering beamforming algorithm is designed using a block DFT algorithm and its performance is analyzed and verified using computer simulations. Various environmental parameters such as the number of antenna elements, the number of users, the mobility of the target user, and the status of fast power control are reflected in the simulation study providing themselves as useful design and implementation guides for the reverse link beamforming of WCDMA system.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.33 no.4C
• /
• pp.336-341
• /
• 2008

In this paper, beamforming algorithm is proposed which can obtain diversity gain in beamforming system that deploy antenna elements with half-wavelength. The proposed algorithm provides beam-pattern using eigen-vectors that span received signal subspace. The criterion to decide optimal rank of eigen-space used for beamforming is also proposed. A beamforming system applied the proposed algorithm shows better performance with diversity gain as getting larger angle spread. This paper provides a description of proposed algorithm with analysis of the performance using various computer simulations.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.28 no.3A
• /
• pp.119-128
• /
• 2003

A space diversity technique was applied to the conventional optimal beamforming structure using antenna arrays at the base station receiver in the wireless mobile communication system to get performance enhancement due to interference rejection and fading resistance ability of it. To demonstrate the benefit of proposed system, we derived output signal to interference plus noise ratio (SINR) of combined signal from all sub-array groups considering the fading effects and compared with the beamforming-only system. From the analysis and simulation results, we showed that the proposed system can provide high performance gain under Rayleigh fading channel.

• The Journal of the Korea Contents Association
• /
• v.9 no.6
• /
• pp.37-44
• /
• 2009

In this paper, we present a switched beamforming RFID reader and propose a convenient shopping system using it. The smart gate with the switched beamforming RFID reader(s) improves tag detection probability, tag false alarm probability, automatic detection functionality of shopping system compared to existing RFID based systems. The proposed system consists of a smart gate to read and verify the tags within cart, a check-out counter to approve customer purchase, and a central server to manage inventory & delivery and to analyze customer purchase trend. The proposed shopping system is more practical, convenient, and cost-effective to A/S than existing RFID shopping systems.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.31 no.12A
• /
• pp.1214-1222
• /
• 2006

In this paper, an efficient direction-r)f-arrival based adaptive beamforming algorithm for orthogonal frequency-division multiple-access smart antenna systems is proposed. The proposed algorithm provides a high performance by steering main beams to the directions of a desired signal, whereas steering nulls to the directions of the interference, using the estimated directions. The beamforming outputs obtained by steering the main beams to the distinct directions of resolvable multipath signals are combined in a maximal ratio manner to exploit angular diversity gain. The performance elf the proposed algorithm is finally evaluated in cellular mobile environments to verify its efficiency and is compared with that of least-squares beamforming algorithm, by taking the WiBro system as a target system.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2015.11a
• /
• pp.43-44
• /
• 2015

LTE-Advanced system has been deployed with 2 and 4 transmission antennas (Tx) while the specification supports up to 8Tx. Due to deployment space, antenna dimension and complexity, the needs of deploying 8Tx system has not been motivated by operators. Recently, three dimensional (3D) beamforming with active antenna has attracted significant attention in the wireless industry. By incorporating 2D active array into LTE-A systems, the system offers freedom in controlling radiation on elevation and horizontal dimension. When the number of antennas increases in the form of 2D arrangement, spatial separation can be realized simultaneously in horizontal and elevation domain and vertical beam-steering can increase SINR of UEs in high floors. In this paper, we study the system operations and implementations for supporting 3D beamforming with 8Tx antennas. In our schemes, by reusing the conventional CSI feedback framework, the system can operate 2D active array without harming the backward compatibility. Evaluation results show that 3D beamforming provides capacity boosting over the conventional 2D beamforming systems while keeping same antenna structure.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.33 no.7A
• /
• pp.727-732
• /
• 2008

The transmit diversity as well as beamforming can increase the performance of wireless communication systems. It is well known that the requirement for the spacing between the neighboring antennas in transmit diversity and beamforming is contradictive to each other. Therefore it is necessary to find the optimum configuration of multiple antennas for getting the maximum performance under the condition that the total number of antennas at transmitter site and the total power of transmitter are fixed. In this paper, the procedure for finding the optimum configuration of multiple antennas was derived through searching the maximum capacity and BER in the combined system with the transmit diversity (Tx diversity) and beamforming.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.15 no.6
• /
• pp.627-633
• /
• 2004

Downlink beamforming is very important in recent mobile communications which requires wireless internet, VOD(Video-On-Demand), multimedia services. This paper addresses and analyzes the essential considerations fur downlink beamforming of smart antenna system to provide wanted characteristics. Major considerations in this paper are HPA power allocation for downlink beamforming, received power at mobile terminal, concept and performance of auxiliary pilot channel, importance and moth of array calibration, and throughput comparison of downlink and uplink. All above mentioned items are investigated in this paper.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.5 no.3
• /
• pp.99-105
• /
• 2009

This paper suggests novel signal processing methods for optimal beamforming of smart antenna system in CDMA2000 mobile communication environments. This method utilize characteristics of the reverse pilot channel of CDMA2000 mobile communication systems, and applies them to improve the performance of an adaptive algorithm, which is used to a smart antenna system for beamforming. To perform the best beamforming, it is important to get an exact beamforming algorithm. This paper proposed an algorithm based on Laglange multiplier which has such an adaptive process, and also proposed the method to demodulate the received signal through array antenna using pilot channel in CDMA2000 environment. This paper analysed the enhanced performance of proposed algorithm in various signal environment through signal modeling of physical layer in CDMA2000 reverse link.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.21 no.1
• /
• pp.29-34
• /
• 2017

This paper considers hybrid beamforming for millimeter wave system in uplink transmission where multiple users send their data streams simultaneously. Hybrid beamforming has low-cost and low power consumption features compared to conventional digital beamforming schemes. We assume that each user uses one transmit antenna and sends one data stream, while the base station has multiple receive antennas and multiple radio frequency chains. Therefore, hybrid beamforming is performed only at the base station. We also assume that each user does not know instantaneous channel side information (CSI), while the base station is able to estimate the CSI from all users accurately. Under this channel assumption, the outage probability is not zero. We evaluate the outage probability of the considered hybrid beamforming as a performance metric through computer simulations. We show that the outage probability of hybrid beamforming approaches that of digital beamforming in some cases.