The Experts below are selected from a list of 1407 Experts worldwide ranked by ideXlab platform

Jun Zhong - One of the best experts on this subject based on the ideXlab platform.

  • an improved frequency Hopping system with no hit zone Hopping Pattern based on adaptive array receiver for anti interference
    Vehicular Technology Conference, 2019
    Co-Authors: Qi Zeng, Xing Liu, Jun Zhong
    Abstract:

    Anti-interference is a major challenge in wireless communications. In this paper, a new set of optimal no-hitzone(NHZ) frequency-Hopping (FH) sequence (so-called NHZ FH Pattern) are constructed, which offers lower frequency-hits than other Hopping Patterns. With such a NHZ FH Pattern, an improved FH system using an adaptive beam-forming (BF) receiver (NHZ/FH-BF system) is investigated for the interference mitigation. By combining NHZ/FH and BF techniques, the proposed system can fully harness the advantage of anti-interference from the spatial and the frequency domains to improve the anti-interference capability. The numerical and simulation results show that the anti-interference performance and the spectral efficiency of the proposed NHZ/FH-BF system significantly outperform the traditional systems, i.e., the NHZ/FH system with single antenna and the FH-BF system with the uniformly-distributed FH Pattern.

  • VTC Spring - An Improved Frequency-Hopping System with No-Hit-Zone Hopping Pattern Based on Adaptive Array Receiver for Anti-Interference
    2019 IEEE 89th Vehicular Technology Conference (VTC2019-Spring), 2019
    Co-Authors: Qi Zeng, Xing Liu, Jun Zhong
    Abstract:

    Anti-interference is a major challenge in wireless communications. In this paper, a new set of optimal no-hitzone(NHZ) frequency-Hopping (FH) sequence (so-called NHZ FH Pattern) are constructed, which offers lower frequency-hits than other Hopping Patterns. With such a NHZ FH Pattern, an improved FH system using an adaptive beam-forming (BF) receiver (NHZ/FH-BF system) is investigated for the interference mitigation. By combining NHZ/FH and BF techniques, the proposed system can fully harness the advantage of anti-interference from the spatial and the frequency domains to improve the anti-interference capability. The numerical and simulation results show that the anti-interference performance and the spectral efficiency of the proposed NHZ/FH-BF system significantly outperform the traditional systems, i.e., the NHZ/FH system with single antenna and the FH-BF system with the uniformly-distributed FH Pattern.

Jiannching Guey - One of the best experts on this subject based on the ideXlab platform.

  • synchronization signal design for ofdm based on time frequency Hopping Patterns
    International Conference on Communications, 2007
    Co-Authors: Jiannching Guey
    Abstract:

    In an OFDM system, channel estimation can be considered as sampling the time-frequency response of the channel through a number of known pilot symbols placed across the time-frequency plane. Sampling theory dictates that the pilot insertion frequency must be above the Nyquist rates in both time and frequency to avoid aliasing of the delay-Doppler response. Based on the regularly spaced pilot Pattern, we can derive alternative Patterns that preserve the non-aliasing property by Hopping the scan lines in either time domain or frequency domain, but not both. From this extended set of Patterns, we find ones with properties that, in addition to channel estimation, can achieve responsively other synchronization tasks such as initial time-frequency offset estimation and device identification. The ambiguity function analysis frequently used in radar signal design leads to a periodic time-Hopping Pattern based on the costas array that has minimal coincidences with its circular time-frequency shifts, which can be used for the identification of multiple devices. The Hopping in time also greatly increases the pilot's time support, thus enabling the quick initial acquisition of timing and frequency offset with very short observation.

  • ICC - Synchronization Signal Design for OFDM Based On Time-Frequency Hopping Patterns
    2007 IEEE International Conference on Communications, 2007
    Co-Authors: Jiannching Guey
    Abstract:

    In an OFDM system, channel estimation can be considered as sampling the time-frequency response of the channel through a number of known pilot symbols placed across the time-frequency plane. Sampling theory dictates that the pilot insertion frequency must be above the Nyquist rates in both time and frequency to avoid aliasing of the delay-Doppler response. Based on the regularly spaced pilot Pattern, we can derive alternative Patterns that preserve the non-aliasing property by Hopping the scan lines in either time domain or frequency domain, but not both. From this extended set of Patterns, we find ones with properties that, in addition to channel estimation, can achieve responsively other synchronization tasks such as initial time-frequency offset estimation and device identification. The ambiguity function analysis frequently used in radar signal design leads to a periodic time-Hopping Pattern based on the costas array that has minimal coincidences with its circular time-frequency shifts, which can be used for the identification of multiple devices. The Hopping in time also greatly increases the pilot's time support, thus enabling the quick initial acquisition of timing and frequency offset with very short observation.

Qi Zeng - One of the best experts on this subject based on the ideXlab platform.

  • an improved frequency Hopping system with no hit zone Hopping Pattern based on adaptive array receiver for anti interference
    Vehicular Technology Conference, 2019
    Co-Authors: Qi Zeng, Xing Liu, Jun Zhong
    Abstract:

    Anti-interference is a major challenge in wireless communications. In this paper, a new set of optimal no-hitzone(NHZ) frequency-Hopping (FH) sequence (so-called NHZ FH Pattern) are constructed, which offers lower frequency-hits than other Hopping Patterns. With such a NHZ FH Pattern, an improved FH system using an adaptive beam-forming (BF) receiver (NHZ/FH-BF system) is investigated for the interference mitigation. By combining NHZ/FH and BF techniques, the proposed system can fully harness the advantage of anti-interference from the spatial and the frequency domains to improve the anti-interference capability. The numerical and simulation results show that the anti-interference performance and the spectral efficiency of the proposed NHZ/FH-BF system significantly outperform the traditional systems, i.e., the NHZ/FH system with single antenna and the FH-BF system with the uniformly-distributed FH Pattern.

  • VTC Spring - An Improved Frequency-Hopping System with No-Hit-Zone Hopping Pattern Based on Adaptive Array Receiver for Anti-Interference
    2019 IEEE 89th Vehicular Technology Conference (VTC2019-Spring), 2019
    Co-Authors: Qi Zeng, Xing Liu, Jun Zhong
    Abstract:

    Anti-interference is a major challenge in wireless communications. In this paper, a new set of optimal no-hitzone(NHZ) frequency-Hopping (FH) sequence (so-called NHZ FH Pattern) are constructed, which offers lower frequency-hits than other Hopping Patterns. With such a NHZ FH Pattern, an improved FH system using an adaptive beam-forming (BF) receiver (NHZ/FH-BF system) is investigated for the interference mitigation. By combining NHZ/FH and BF techniques, the proposed system can fully harness the advantage of anti-interference from the spatial and the frequency domains to improve the anti-interference capability. The numerical and simulation results show that the anti-interference performance and the spectral efficiency of the proposed NHZ/FH-BF system significantly outperform the traditional systems, i.e., the NHZ/FH system with single antenna and the FH-BF system with the uniformly-distributed FH Pattern.

Huahui Wang - One of the best experts on this subject based on the ideXlab platform.

  • Spectrally Efficient Jamming Mitigation Based on Code-Controlled Frequency Hopping
    IEEE Transactions on Wireless Communications, 2011
    Co-Authors: Huahui Wang, Lei Zhang, Jitendra K. Tugnait
    Abstract:

    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.

  • ICASSP - Code-controlled 3D frequency Hopping for jamming mitigation
    2010 IEEE International Conference on Acoustics Speech and Signal Processing, 2010
    Co-Authors: Huahui Wang
    Abstract:

    This paper considers spectrally efficient anti-jamming system design based on coded three-dimensional (3D) frequency Hopping. Unlike conventional frequency Hopping systems where the Hopping Pattern is determined by a preselected pseudo-random sequence, in the proposed scheme, part of the information is passed through a block encoder, and used to determine the selected frequency bands for signal transmission. The receiver is designed to retrieve the Hopping Pattern without a priori knowledge. The proposed system can effectively mitigate random jamming interference while maintaining high spectral efficiency. Simulation results are provided to illustrate the system's jamming mitigation performance.

Hongwen Yang - One of the best experts on this subject based on the ideXlab platform.

  • PIMRC - Enabling NB-IoT on Unlicensed Spectrum
    2019 IEEE 30th Annual International Symposium on Personal Indoor and Mobile Radio Communications (PIMRC), 2019
    Co-Authors: Rongrong Sun, Salvatore Talarico, Wenting Chang, Huaning Niu, Hongwen Yang
    Abstract:

    The deployment of Internet of Things (IoT) technologies in unlicensed spectrum is a candidate feature for 5G to support massive connections of IoT devices. Current IoT unlicensed band technologies, such as Sigfox and LoRa, are all at an early stage of deployment without a significant market share. In this context, the MulteFire (MF) Alliance has envisioned to adapt the cellular NB-IoT design to operate within the Sub-1 GHz unlicensed spectrum. However, the diverse regulatory requirements within this unlicensed band put a hurdle to the worldwide deployment of unlicensed band IoT technologies. To settle this challenge, MF has designed a specific framework for narrow-band (NB)-IoT systems operating on unlicensed spectrum (NB-IoT-U), which can be utilized under both the Federal Communications Commission (FCC) and European Telecommunication Standards Institute (ETSI) regulatory requirements. In this paper, enhanced synchronization and physical broadcasting signals are proposed based upon the framework designed by MF with the aim to allow a more robust detection, and to fulfil the coverage targets set for this technology. Furthermore, in order to allow the system to operate as a frequency Hopping spread spectrum (FHSS) system, a novel frequency Hopping Pattern generator compliant with the regulatory requirements is designed, and its performance is evaluated.

  • Enabling NB-IoT on Unlicensed Spectrum
    arXiv: Signal Processing, 2019
    Co-Authors: Rongrong Sun, Salvatore Talarico, Wenting Chang, Huaning Niu, Hongwen Yang
    Abstract:

    The deployment of Internet of Things (IoT) technologies in unlicensed spectrum is a candidate feature for 5G to support massive connections of IoT devices. Current IoT unlicensed band technologies, such as Sigfox and LoRa, are all at an early stage of deployment without a significant market share. In this context, the MulteFire (MF) Alliance has envisioned to adapt the cellular NB-IoT design to operate within the Sub-1 GHz unlicensed spectrum. However, the diverse regulatory requirements within this unlicensed band put a hurdle to the world-wide deployment of unlicensed band IoT technologies. To settle this challenge, MF has designed a specific framework for narrow-band (NB)-IoT systems operating on unlicensed spectrum (NB-IoT-U), which can be utilized under both the Federal Communications Commission (FCC) and European Telecommunication Standards Institute (ETSI) regulatory requirements. In this paper, enhanced synchronization and physical broadcasting signals are proposed based upon the framework designed by MF with the aim to allow a more robust detection, and to fulfil the coverage targets set for this technology. Furthermore, in order to allow the system to operate as a frequency Hopping spread spectrum (FHSS) system, a novel frequency Hopping Pattern generator compliant with the regulatory requirements is designed, and its performance is evaluated.