The Experts below are selected from a list of 21240 Experts worldwide ranked by ideXlab platform
Chen B - One of the best experts on this subject based on the ideXlab platform.
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Synchronization Technology Research Based on Fast-Slow Frequency Hopping
Computer Simulation, 2014Co-Authors: Chen BAbstract:Fast Frequency Hopping system has the characteristics of fast hop rate and transmitting a modulation symbol by per hop or multi-hop,which makes it difficult to carry the correlation code and to achieve fast Frequency Hopping communication. For the limitation of fast Frequency Hopping,a scheme of Frequency Hopping synchronization of time information TOD synchronization prefix was proposed in this paper based on the combination of fast and slow Frequency Hopping. In synchronization establishment phase,slow Frequency Hopping was used,and the flag information indicated that the fast Frequency Hopping used in data transmission phase was added in the synchronization information frame format. This scheme combines the characteristics of fast and slow Frequency Hopping communication, which can meet the communication needs of slow Frequency Hopping changing to fast Frequency Hopping when synchronization phase changes to data phase. The performance of the scheme was analyzed,and the simulation results show that the scheme of Frequency Hopping synchronization has the advantages of short synchronization time,high capturing probability and low false alarm probability.
J Naslund - One of the best experts on this subject based on the ideXlab platform.
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interference diversity gain in Frequency Hopping gsm
Vehicular Technology Conference, 1995Co-Authors: H. Olofsson, J Naslund, J SkoldAbstract:Wideband random Frequency Hopping is one of the key properties of GSM in an evolution towards PCS (personal communication services). Random Frequency Hopping introduces diversity on the transmission link, which improves the performance. In this paper, the impact of interference diversity in GSM is analyzed by means of bit level simulations of the GSM full rate speech channel. The analysis shows that the gain of interference diversity is highly system load dependent. The interference diversity gain is most striking in a system with low channel utilization. These results, together with system level simulations of Frequency Hopping GSM, show that random Frequency Hopping has implications for Frequency planning. They indicate that GSM systems with simple Frequency planning can be designed without sacrificing the overall system quality.
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fh gsm Frequency Hopping gsm
Vehicular Technology Conference, 1994Co-Authors: C Carneheim, S O Jonsson, M Ljungberg, M Madfors, J NaslundAbstract:The GSM system of today is evolving towards smaller cells and higher traffic capacity. The need for microcell and even picocell systems will be greatly increased in the near future. One of the most important factors will then be to provide high traffic capacity and to provide an easy way of performing Frequency planning for the system operator. In this paper we present results from system simulations based on the GSM recommendation phase two. We show that the use of power regulation in both up- and downlink in combination with discontinuous transmission (DTX) and slow Frequency Hopping makes it possible to decrease the Frequency reuse distance below 3/9 whilst maintaining system performance. Results from simulations with different Frequency reuse distances are presented. System characteristics such as capacity, quality and robustness are evaluated and compared to a fixed plan reference system without Frequency Hopping or DTX. >
Jitendra K. Tugnait - One of the best experts on this subject based on the ideXlab platform.
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Spectrally Efficient Jamming Mitigation Based on Code-Controlled Frequency Hopping
IEEE Transactions on Wireless Communications, 2011Co-Authors: Huahui Wang, Lei Zhang, Jitendra K. TugnaitAbstract:This paper considers spectrally efficient anti-jamming system design based on code-controlled Frequency Hopping. Unlike conventional Frequency Hopping systems where Hopping patterns are determined by preselected pseudo-random sequences, in the proposed scheme, part of source information is passed through a block encoder, and used to determine the selected Frequency bands for signal transmission. By exploiting the redundancy provided by the block coding, the receiver can retrieve the Hopping pattern without a priori knowledge. Through an integrated decoding-and-encoding process, the receiver can also perform partial jamming detection. It is observed that due to the combination of dynamic Frequency Hopping and coding diversities, the proposed system can effectively mitigate random jamming interference while maintaining high spectral efficiency.
J Skold - One of the best experts on this subject based on the ideXlab platform.
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interference diversity gain in Frequency Hopping gsm
Vehicular Technology Conference, 1995Co-Authors: H. Olofsson, J Naslund, J SkoldAbstract:Wideband random Frequency Hopping is one of the key properties of GSM in an evolution towards PCS (personal communication services). Random Frequency Hopping introduces diversity on the transmission link, which improves the performance. In this paper, the impact of interference diversity in GSM is analyzed by means of bit level simulations of the GSM full rate speech channel. The analysis shows that the gain of interference diversity is highly system load dependent. The interference diversity gain is most striking in a system with low channel utilization. These results, together with system level simulations of Frequency Hopping GSM, show that random Frequency Hopping has implications for Frequency planning. They indicate that GSM systems with simple Frequency planning can be designed without sacrificing the overall system quality.
Huahui Wang - One of the best experts on this subject based on the ideXlab platform.
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Spectrally Efficient Jamming Mitigation Based on Code-Controlled Frequency Hopping
IEEE Transactions on Wireless Communications, 2011Co-Authors: Huahui Wang, Lei Zhang, Jitendra K. TugnaitAbstract:This paper considers spectrally efficient anti-jamming system design based on code-controlled Frequency Hopping. Unlike conventional Frequency Hopping systems where Hopping patterns are determined by preselected pseudo-random sequences, in the proposed scheme, part of source information is passed through a block encoder, and used to determine the selected Frequency bands for signal transmission. By exploiting the redundancy provided by the block coding, the receiver can retrieve the Hopping pattern without a priori knowledge. Through an integrated decoding-and-encoding process, the receiver can also perform partial jamming detection. It is observed that due to the combination of dynamic Frequency Hopping and coding diversities, the proposed system can effectively mitigate random jamming interference while maintaining high spectral efficiency.