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The paper analyzes the research background of present-day information network and technologies firstly. And then we introduce the main work and some achievements in BJTU NGIRC in recent years. We also introduce the future research work in BJTU NGIRC.
This paper reviews the state-of-the-art in reconfigurable multifunction antenna technology, including antennas with compound reconfigurability and integrated switching mechanisms. System-level demonstrations of some antennas are also highlighted. Possible directions for future research in this area are discussed, with an emphasis on bringing reconfigurable antennas together with other system components...
The next-generation high data rate wireless communication systems are expected to offer a completely new ways to access information and services. The need of higher data transfer rate and bandwidth, along with the requirement for low-cost, high efficiency system implementation, has led to an explosion in new technology development for integrated circuit approaches in RF/microwave area, RF receiver&...
The performance of ultrawideband (UWB) communications systems is determined by the propagation channels they operate in. This paper gives an overview of UWB channels and their impact on system design. The emphasis lies on (i) multiple-antenna systems and (ii) body-area networks. We discuss the frequency dependence of angular power spectra and show that spatial multiplexing can be used for achieving...
The following topics were covered: systems and services; microwave electronics; antennas; propagation; electromagnetics; signal processing; signal coding, waveforms; EMC; micro-electronic devices; micro-electronic circuits; micro-electronic systems; wireless applications; and remote sensing.
In this paper, we present a dynamic resource allocation algorithm, termed Dynamic Major group Allocation (DMA), based on Soft Frequency Reuse (SFR) which is an efficient method to mitigate inter-cell interference (ICI) in Orthogonal Frequency Division Multiple Access (OFDMA) systems. DMA defines the method that Radio Network Controller (RNC) orthogonally assigns resource to Cell Edge Users (CEU) in...
In the 3GPP Long term Evolution system, one of the key techniques to meet the performance requirements in the downlink is the frequency selective schedule (FSS), in which resource allocation and modulation and code schemes are changed adaptively according to the downlink channel quality reported by user equipments (IE). Therefore, the channel quality information (CQI) scheme will directly affect the...
The capacity of MIMO-OFDM system can be increased substantially through spatial multiplexing with linear unitary precoding technique which requires that full channel state information should be sent back to transmitter. To reduce the feedback overhead, we give a codebook of precoding matrices that is known to both transmitter and receiver. A matrix is selected at the receiver, and then its index is...
This paper firstly investigates an optimal parallel interference cancellation (PIC) scheme for an asynchronous DS/CDMA system. Secondly, to reduce the high implementation complexity encountered by the optimal PIC, we propose a low-complexity PIC by simplifying decision complexity and taking weight of the estimated multi-access interference for each interference cancellation (IC) stage. The performance...
In this paper, a new Rake receiver of the Ultra-wide band (UWB) system with multiple receive antennas is proposed. To economize the system resource, an antenna selection scheme is used. For each selected antenna, the maximal ratio RAKE combination is applied to the multi-path signals. The outputs corresponding to all selected antennas are then combined according to the minimum mean square error (MMSE)...
This paper describes the theory, technical features and benefits of a new Synchronous FM system. We have provided the user with the whole Audio Transmission System and Digital FM Exciter solution, which is crucial for the Implementation of Synchronous FM.
In this paper, we propose a new transmission scheme for railway wireless communication. By realizing single frequency network based on OFDM, we improved the performance of GSM-R by realizing "soft handover" . And in order to improve our system' s performance in frequency selective multipath channel, we adopt generalized Multi-Carrier-CDMA (GMC-CDMA) scheme to optimize our system. Relying...
Power control is one of the key technologies in radio resource management, and efficient power control scheme can decrease the interference to other users and save the power consumption. In cognitive radio network, the interference caused by unlicensed user to licensed user is strictly limited. In order to maximize the network utility, a game theoretic approach is proposed. In this paper, a new power...
CDD is a transmit diversity method with high flexibility and low complexity in MIMO-OFDM system. It can be extended to SFN or MBMS application. In this paper, CDD in SFN is analyzed firstly. The value of delay parameter is very crucial providing to the receiver performance if cell common pilot pattern is used. A new channel estimator for CDD and corresponding pilot pattern is presented and analyzed...
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