Internet-of-things (IoT) is an enabling technology in the fourth generation industrial revolution. An unified performance metric named age of information (AoI) is introduced to quantify the freshness of data and its a...
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Internet-of-things (IoT) is an enabling technology in the fourth generation industrial revolution. An unified performance metric named age of information (AoI) is introduced to quantify the freshness of data and its a...
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In heterogeneous networks, network selection is an impor-tant task for reconfigurable mobile devices (MDs). In the reconfigurable MD architecture that has been standardized by the European Telecommu-nications Standard...
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In heterogeneous networks, network selection is an impor-tant task for reconfigurable mobile devices (MDs). In the reconfigurable MD architecture that has been standardized by the European Telecommu-nications Standards Institute (ETSI), the network selection functionality is handled by a software component called Mobility Policy Manager (MPM). In this paper, we present an implementation of theMPMwhereby a reconfig-urableMDconforming to the ETSI standard can select the most appropriate radio access network (RAN) to use. We implemented a reconfigurable MD test-bed compliant with the ETSI standard, and show that the network se-lection driven by the MPM enhances the throughput of the receivingMDby about 26% compared to the arbitrary network selection provided by a con-ventional reconfigurable MD without the functionality of MPM, verifying the functionality of the MPM.
In this paper, we propose a design rule of a modified quasi-cyclic structure for bit-interleaved coded modulation with iterative decoding (BICM-ID). The proposed structure is especially favorable for low-complexity ha...
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ISBN:
(纸本)9781467371179
In this paper, we propose a design rule of a modified quasi-cyclic structure for bit-interleaved coded modulation with iterative decoding (BICM-ID). The proposed structure is especially favorable for low-complexity hardware implementation. In addition, it will be shown that the proposed structure effectively removes low-weight codewords, which in turn greatly improves error-floor behaviors as compared to quasi-cyclic interleaver.
The HARQ enables the error correction of the unsuccessfully decoded transport block, but it requires redundancy retransmissions and delay in receiving an acknowledgement. In order to provide the flexibility of schedul...
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The HARQ enables the error correction of the unsuccessfully decoded transport block, but it requires redundancy retransmissions and delay in receiving an acknowledgement. In order to provide the flexibility of schedul...
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ISBN:
(纸本)9781457711534
The HARQ enables the error correction of the unsuccessfully decoded transport block, but it requires redundancy retransmissions and delay in receiving an acknowledgement. In order to provide the flexibility of scheduling, the DL of LTE system uses the asynchronous HARQ so that retransmissions occur at any time. Generally in the FDD, the HARQ round trip time (RTT) which is time interval between initial transmission and retransmission is fixed. In the TDD, UL/DL subframe is separated in time domain by UL-DL configuration, so the HARQ RTT is different according to each subframe and that would be longer than the FDD. Especially when retransmissions occur, if the HARQ RTT increases, the QoS requirement of the retransmitted packet would not be satisfied by increased end-to-end latency. In this paper, we suggest the method of implementing DL asynchronous HARQ in LTE TDD system that the eNB can apply by UL-DL configuration as minimizing the HARQ RTT, and analyze in aspect of the HARQ RTT.
A large variety of countries all over the world have established GPS reference station networks in the last years and are using network software today to provide a correction stream to the user as a routine service. T...
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A large variety of countries all over the world have established GPS reference station networks in the last years and are using network software today to provide a correction stream to the user as a routine service. These data streams are corrected for regional atmospheric effects, orbit errors and other systematic effects derived from the network solution. Currently most of these installations are using the VRS (Virtual Reference Station) technique to transport the correction stream in form of RTCM 2.3, RTCM 3.0 or CMR from the server to the field user. The VRS technique requires bidirectional communication, which is available via GSM, GPRS and other cell phone based data transmission methods. While the VRS method is the most common technique used, the RTCM committee is currently discussing a network proposal for broadcast transmission of network corrections, which will be useful for radio systems and Internet based multicast solutions. The focus of the paper is on the characterization of the influence of different interpolation schemes and the ability to derive tropospheric and ionospheric models. In the VRS case these models and interpolation schemes are applied in the server while they are applied in the rover in the RTCM network format case. Advantages and disadvantages of both methods are presented. Other aspects discussed are the required bandwidth for the different formats, the influence of the network message update rates, the influence of the scheduling on the start up of the RTK rover and the effect of different network shapes on the rover performance. The paper presents results of performance analyses performed to compare the VRS solution with the RTCM network solution in different networks. Accuracy, initialization performance and reliability of RTK systems working with the formats are compared to quantify the performance differences.
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