The coexistence between Bluetooth system and IEEE 802.11 frequency hoppingspread spectrum (FHSS) equipment is analyzed. Based on the capacity formulae and system simulation,the inter-affection between these networks i...
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The coexistence between Bluetooth system and IEEE 802.11 frequency hoppingspread spectrum (FHSS) equipment is analyzed. Based on the capacity formulae and system simulation,the inter-affection between these networks is compared. A fragment adaptive solution of packetpayload length is presented, which can be used to improve the capacity reduction of IEEE 802.11 FHSSnetwork. Analysis results show that the IEEE 802.11 WLAN standard with its inherent mechanismsupports this fragment length adaptive algorithm. With the increasing of Bluetooth interferingnetworks, this adaptive solution can effectively relieve capacity decreasing of IEEE 802.11 FHSSnetwork. The capacity analysis method and adaptive algorithm adopted in this paper can also begeneralized into other FHSS networks.
In the scenario of multiple wireless personal area networks （WPANs） accessing the home area network （HAN）, the frequency-shift （FRESH）filter based on the cyclostationary theory is applied for the anti-interferen...
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In the scenario of multiple wireless personal area networks （WPANs） accessing the home area network （HAN）, the frequency-shift （FRESH）filter based on the cyclostationary theory is applied for the anti-interference at the 2. 4 GHz spectrum. The main architecture of multiple WPANs accessing the HAN is proposed. The medium access control（ MAC） -level coordination solution applied in the access point （AP）for the coexistence of different communication protocols within WPAN is discussed. The diagram of the adaptive FRESH filter is described. The anti-interference models of the FRESH filter in the scenario of multiple WPANs accessing the HAN are proposed. The minimum mean square error （MMSE）convergence property of the FRESH filter with the change in the data point number is analyzed. The simulation results indicate that the FRESH filter can effectively extract the signal of interest （SOI） from the interference with the partly overlapped spectrum. Thus, the excellent anti-interference performance of the FRESH filter is validated. Moreover, by both theoretical analysis and simulation, the MMSE convergent property of the FRESH filter is also proven.
A flame length optimization scheme is proposed for multi-antenna downlink systems to guarantee diverse delay- bound violation probability constraints. Due to the difficulties of extracting the quality of service （QoS...
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A flame length optimization scheme is proposed for multi-antenna downlink systems to guarantee diverse delay- bound violation probability constraints. Due to the difficulties of extracting the quality of service （QoS） metrics from the conventional physical-layer channel models, the link-layer models named effective bandwidth and effective capacity are applied to statistically characterize the source traffic patterns and the queuing service dynamics. With these link-layer models, the source traffic process and the channel service process are mapped to certain QoS parameters. The packet delay-bound violation probability constraints are converted into minimum data rate constraints and the optimization problem is thus formulated into simultaneous inequalities. With the assumption of ergodic block-fading channels, the optimal frame lengths of single-user and multiuser systems are calculated respectively by numerical iterative methods. Theoretical analyses and simulation results show that the given delay-bound violation probability constraints are well satisfied with the optimal frame length.
Abts ract A wireless mutl i-hop videot ransmission experiment system is designed and implemented for vehiculra ad-hoc networks VANET and the rt ansm ission control protocol and routing protocol are proposed. This syst...
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Abts ract A wireless mutl i-hop videot ransmission experiment system is designed and implemented for vehiculra ad-hoc networks VANET and the rt ansm ission control protocol and routing protocol are proposed. This system in tegrates the embedded Linux system witha n ARM kernel and oc ns ists of a S3C6410 main control module a wirel ss local arean etwork WLAN card a LCD screne and so *** the scenario of a wireless multi-hop video transmission both the H.264 and JPEG are used and their performances such as the compression rate delay and frame loss rate are analyzed in theory andc ompared in the *** system is tested in the real indoor and outdoor *** results show that the scheme of the multi-hop video transmission experiment system can be applicable for VANET and multiple scenes and the transmission control protocol and routing protocol proposed can achieve real-time transmission and meet multi-hop requirements.
Based on the principle of information theory, a novel scheme of unequal-interval frequency-hopping (FH) systems was proposed. For cases of spectrum overlapping systems and non-overlapping systems, the implementation m...
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Based on the principle of information theory, a novel scheme of unequal-interval frequency-hopping (FH) systems was proposed. For cases of spectrum overlapping systems and non-overlapping systems, the implementation methods were presented and the security performances were discussed theoretically. Firstly, the definitions of absolute and relative key amounts of FH systems, equal-interval and unequal-interval FH systems were given. Then, the absolute key amount and relative key amount were analyzed for equal-interval and unequal-interval FH systems. The results indicated that the absolute key amount had become the key point in improving the security and secrecy of FH systems, especially in today's epoch of highly developed computer science and IC design technology. Theoretical analysis and practical examples showed that the absolute key amount of unequal-interval FH systems was generally over two orders larger than that of equal-interval ones when spectrum overlapping was allowable. Therefore, there was great superiority in enhancing the security and secrecy for the scheme mentioned.
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