The Experts below are selected from a list of 29799 Experts worldwide ranked by ideXlab platform

A B Sesay - One of the best experts on this subject based on the ideXlab platform.

  • null sub carrier aided reference symbol Mapping for improved channel estimation in 3gpp lte downlink
    Vehicular Technology Conference, 2010
    Co-Authors: Siva Muruganathan, Witold A Krzymien, A B Sesay
    Abstract:

    In this paper, a new reference symbol Mapping Scheme is proposed to improve downlink channel estimation performance over the standard reference symbol Mapping Scheme defined in the 3GPP LTE standard. The proposed Scheme is based on the concept of guarding reference symbols (i.e., pilot symbols) with null sub-carriers. This helps mitigate the effect of inter-carrier interference (ICI) at pilot sub-carriers. In addition, the proposed Scheme allows the ICI gain parameters to be estimated via a simple estimator. To assess the relative merits of the proposed reference symbol Mapping Scheme over the standard Scheme, we compare normalized mean square error and uncoded bit error rate performances of the two Schemes under different mobile user speeds. These comparisons show excellent performance improvements achieved by the proposed Scheme over the standard one at high mobile user speeds.

  • null sub carrier aided reference symbol Mapping for improved channel estimation in 3gpp lte downlink
    Vehicular Technology Conference, 2010
    Co-Authors: Siva Muruganathan, Witold A Krzymien, A B Sesay
    Abstract:

    In this paper, a new reference symbol Mapping Scheme is proposed to improve downlink channel estimation performance over the standard reference symbol Mapping Scheme defined in the 3GPP LTE standard. The proposed Scheme is based on the concept of guarding reference symbols (i.e., pilot symbols) with null sub-carriers. This helps mitigate the effect of inter-carrier interference (ICI) at pilot sub-carriers. In addition, the proposed Scheme allows the ICI gain parameters to be estimated via a simple estimator. To assess the relative merits of the proposed reference symbol Mapping Scheme over the standard Scheme, we compare normalized mean square error and uncoded bit error rate performances of the two Schemes under different mobile user speeds. These comparisons show excellent performance improvements achieved by the proposed Scheme over the standard one at high mobile user speeds.

Siva Muruganathan - One of the best experts on this subject based on the ideXlab platform.

  • null sub carrier aided reference symbol Mapping for improved channel estimation in 3gpp lte downlink
    Vehicular Technology Conference, 2010
    Co-Authors: Siva Muruganathan, Witold A Krzymien, A B Sesay
    Abstract:

    In this paper, a new reference symbol Mapping Scheme is proposed to improve downlink channel estimation performance over the standard reference symbol Mapping Scheme defined in the 3GPP LTE standard. The proposed Scheme is based on the concept of guarding reference symbols (i.e., pilot symbols) with null sub-carriers. This helps mitigate the effect of inter-carrier interference (ICI) at pilot sub-carriers. In addition, the proposed Scheme allows the ICI gain parameters to be estimated via a simple estimator. To assess the relative merits of the proposed reference symbol Mapping Scheme over the standard Scheme, we compare normalized mean square error and uncoded bit error rate performances of the two Schemes under different mobile user speeds. These comparisons show excellent performance improvements achieved by the proposed Scheme over the standard one at high mobile user speeds.

  • null sub carrier aided reference symbol Mapping for improved channel estimation in 3gpp lte downlink
    Vehicular Technology Conference, 2010
    Co-Authors: Siva Muruganathan, Witold A Krzymien, A B Sesay
    Abstract:

    In this paper, a new reference symbol Mapping Scheme is proposed to improve downlink channel estimation performance over the standard reference symbol Mapping Scheme defined in the 3GPP LTE standard. The proposed Scheme is based on the concept of guarding reference symbols (i.e., pilot symbols) with null sub-carriers. This helps mitigate the effect of inter-carrier interference (ICI) at pilot sub-carriers. In addition, the proposed Scheme allows the ICI gain parameters to be estimated via a simple estimator. To assess the relative merits of the proposed reference symbol Mapping Scheme over the standard Scheme, we compare normalized mean square error and uncoded bit error rate performances of the two Schemes under different mobile user speeds. These comparisons show excellent performance improvements achieved by the proposed Scheme over the standard one at high mobile user speeds.

Gaojie Chen - One of the best experts on this subject based on the ideXlab platform.

  • Adaptive OFDM With Index Modulation for Two-Hop Relay-Assisted Networks
    IEEE Transactions on Wireless Communications, 2018
    Co-Authors: Shuping Dang, Justin P. Coon, Gaojie Chen
    Abstract:

    In this paper, we propose an adaptive orthogonal frequency-division multiplexing with index modulation (OFDM-IM) for two-hop relay networks. In contrast to the traditional OFDM-IM with a deterministic and fixed Mapping Scheme, in this proposed adaptive OFDM-IM, the Mapping Schemes between a bit stream and indices of active subcarriers for the first and second hops are adaptively selected by a certain criterion. As a result, the active subcarriers for the same bit stream in the first and second hops can be varied in order to combat slow frequency-selective fading. In this way, the system reliability can be enhanced. In addition, considering the fact that a relay device is normally a simple node, which may not always be able to perform Mapping Scheme selection due to limited processing capability, we also propose an alternative adaptive methodology in which the Mapping Scheme selection is only performed at the source and the relay will simply utilize the selected Mapping Scheme without changing it. The analyses of average outage probability, network capacity, and symbol error rate are given in closed form for decode-and-forward relaying networks and are substantiated by numerical results generated by Monte Carlo simulations.

Witold A Krzymien - One of the best experts on this subject based on the ideXlab platform.

  • null sub carrier aided reference symbol Mapping for improved channel estimation in 3gpp lte downlink
    Vehicular Technology Conference, 2010
    Co-Authors: Siva Muruganathan, Witold A Krzymien, A B Sesay
    Abstract:

    In this paper, a new reference symbol Mapping Scheme is proposed to improve downlink channel estimation performance over the standard reference symbol Mapping Scheme defined in the 3GPP LTE standard. The proposed Scheme is based on the concept of guarding reference symbols (i.e., pilot symbols) with null sub-carriers. This helps mitigate the effect of inter-carrier interference (ICI) at pilot sub-carriers. In addition, the proposed Scheme allows the ICI gain parameters to be estimated via a simple estimator. To assess the relative merits of the proposed reference symbol Mapping Scheme over the standard Scheme, we compare normalized mean square error and uncoded bit error rate performances of the two Schemes under different mobile user speeds. These comparisons show excellent performance improvements achieved by the proposed Scheme over the standard one at high mobile user speeds.

  • null sub carrier aided reference symbol Mapping for improved channel estimation in 3gpp lte downlink
    Vehicular Technology Conference, 2010
    Co-Authors: Siva Muruganathan, Witold A Krzymien, A B Sesay
    Abstract:

    In this paper, a new reference symbol Mapping Scheme is proposed to improve downlink channel estimation performance over the standard reference symbol Mapping Scheme defined in the 3GPP LTE standard. The proposed Scheme is based on the concept of guarding reference symbols (i.e., pilot symbols) with null sub-carriers. This helps mitigate the effect of inter-carrier interference (ICI) at pilot sub-carriers. In addition, the proposed Scheme allows the ICI gain parameters to be estimated via a simple estimator. To assess the relative merits of the proposed reference symbol Mapping Scheme over the standard Scheme, we compare normalized mean square error and uncoded bit error rate performances of the two Schemes under different mobile user speeds. These comparisons show excellent performance improvements achieved by the proposed Scheme over the standard one at high mobile user speeds.

Shuping Dang - One of the best experts on this subject based on the ideXlab platform.

  • Adaptive OFDM With Index Modulation for Two-Hop Relay-Assisted Networks
    IEEE Transactions on Wireless Communications, 2018
    Co-Authors: Shuping Dang, Justin P. Coon, Gaojie Chen
    Abstract:

    In this paper, we propose an adaptive orthogonal frequency-division multiplexing with index modulation (OFDM-IM) for two-hop relay networks. In contrast to the traditional OFDM-IM with a deterministic and fixed Mapping Scheme, in this proposed adaptive OFDM-IM, the Mapping Schemes between a bit stream and indices of active subcarriers for the first and second hops are adaptively selected by a certain criterion. As a result, the active subcarriers for the same bit stream in the first and second hops can be varied in order to combat slow frequency-selective fading. In this way, the system reliability can be enhanced. In addition, considering the fact that a relay device is normally a simple node, which may not always be able to perform Mapping Scheme selection due to limited processing capability, we also propose an alternative adaptive methodology in which the Mapping Scheme selection is only performed at the source and the relay will simply utilize the selected Mapping Scheme without changing it. The analyses of average outage probability, network capacity, and symbol error rate are given in closed form for decode-and-forward relaying networks and are substantiated by numerical results generated by Monte Carlo simulations.