Tan Hanh

Radio over fiber signal generation and distribution and its application to train communication network

Radio over fiber signal generation by an ultra-fast wavelength-tunable laser under wavelength-division-multiplexing configuration is demonstrated for radio signal delivery to remote sites in a linear-cell-based distributed antenna system. Application to linear-cell train communication system is discussed.

Down-link cooperative transmission with transmit antenna selection, hardware noises and non-independent co-channel interferences

In this paper, we propose and evaluate performances of a down-link cooperative transmission scheme with joint impact of imperfect hardware and non-independent co-channel interference. In the proposed scheme, a base station (BS) uses transmit antenna selection (TAS) technique to transmit its data to its intended user (US). Moreover, one of potential relay stations (RS) in the network is selected to help the BS relay the data to the US which uses selection combining (SC) technique to combine the received data. We derive exact and asymptotic expressions of outage probability over Rayleigh fading channel. The derivations are then verified by computer simulations.

Joint impact of hardware impairment and co-channel interference on multi-hop relaying

Relaying transmission enables the high performance of wireless communication systems. Therefore, many researches have investigated this technique. However, most of the studies supposed the ideal-hardware and ignored the co-channel interference. For accuracy design, it highly motivates to account for hardware impairment and interference in analyzing relaying systems. In this paper, we model the multi-hop relaying channel, considering both hardware impairment and co-channel interference. We then analyze the performance of the system in terms of outage probability and ergodic capacity. Specially, the exact and asymptotic (at high signal-to-noise and interference ratio) closedform expressions of outage probability and ergodic capacity are both given over Rayleigh fading channels.

Extracting semantic relations between vietnamese legislative documents

The semantic relations between entities in documents play vital roles in many applications such as information extraction, and information retrieval. The problem of extracting the semantic relations in Vietnamese documents is more difficult because Vietnamese textual analysis tools are in progress. In this paper, we propose an approach based on syntactic dependency feature between provisions in each sentence and the Support Vector Machine classifier to extract the semantic relations between entities in Vietnamese documents. Our results show that syntactic dependency method is more stable and accuracy (F-measure) than the regular expression method especially for long and complex texts of Vietnamese legislative documents.

An incremental cooperative solution for multicast cognitive network under joint impact of hardware impairment and interference constraint

In this paper, we investigate joint impact of hardware transceiver impairment and interference constraint on performances of cooperative relaying protocols in underlay cognitive radio. In the proposed protocol, a secondary source uses incremental cooperative technique to transmit its data to multiple secondary destinations via a secondary relay. We derive exact and asymptotic expressions of the outage probability and average number of the secondary destinations which successfully receive the source data. All of the derivations are validated by computer simulations using Monte Carlo methods.

Monitoring Hot-IPs in high speed networks

Network monitoring system is an important task for network administrator to monitor states of the operation of network devices, servers, network services, or network traffics. This task is often solved by setting-up a monitoring server and implement agents at monitored objects. This paper presents a solution to monitor Hot-IPs in high speed network at ISP side. It does not need to specify which objects should be monitored and also does not need to establish connections between the network monitoring system and these monitored servers or setup agents in these servers. This solution can be applied at ISP networks to reduce some risks on Internet network and early alert to customers. In proposed solution, Hot-IPs will be fast detected using Non-adaptive group testing and then transfer to monitor mode. At this mode, Hot-IPs are monitored to determine what is a risk and what is not.