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Slow Frequency Hopping Assisted MC DS-CDMA using Large Area Synchronised Spreading Sequences

机译：采用大面积同步扩频序列的慢跳频辅助mC Ds-CDma

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摘要

The family of Multi-Carrier Direct-Sequence CDMA (MC DS- CDMA) systems exhibits numerous attractive properties, which render them attractive candidates for next-generation wireless communications. We demonstrate that spreading codes exhibiting a so-called interference-free window (IFW) are capable of outperforming classic spreading codes, when the interfering multi-user and multipath components arrive within this IFW. The best possible quasi-synchronous timing of the spreading sequences has to be adjusted with the aid of accurate adaptive timing advance control, which has to be significantly more accurate than that used in the lower-bit-rate second-generation GSM system. Fortunately, the IFW duration may be extended with the advent of multi-carrier DS-CDMA proportionately to the number of subcarriers. Hence the resultant MC DS-CDMA system is capable of exhibiting a near-single-user performance without employing a multi-user detector. A deficiency of the resultant system is that the number of spreading codes exhibiting a certain IFW is limited and so is the IFW duration. This contribution sets out to mitigate the above-mentioned shortcomings so that when the users' delays are in the range of the IFW, we separate them with the aid of the unique, user-specific LAS spreading codes. By contrast, when the users roam at a high distance from the base-station and hence their received signal arrive outside the range of the IFW, we separate them using their unique frequency hopping patterns.
机译：多载波直接序列CDMA（MC DS-CDMA）系统系列具有众多吸引人的特性，这使其成为下一代无线通信的诱人候选人。我们证明，当有干扰的多用户和多径分量到达此IFW时，展现出所谓的无干扰窗口（IFW）的扩展码能够胜过经典的扩展​​码。必须借助精确的自适应定时提前控制来调整扩展序列的最佳准准同步定时，该控制必须比在低比特率的第二代GSM系统中精确得多。幸运的是，随着多载波DS-CDMA的出现，IFW持续时间可以与子载波的数量成比例地延长。因此，所得到的MC DS-CDMA系统能够在不采用多用户检测器的情况下表现出接近单用户的性能。所得系统的不足之处在于，表现出一定IFW的扩频码数量受到限制，IFW持续时间也受到限制。该贡献旨在减轻上述缺点，以便当用户的延迟在IFW范围内时，我们借助独特的，用户特定的LAS扩展码将它们分开。相比之下，当用户在距基站很远的距离漫游并因此其接收信号到达IFW范围之外时，我们将使用其独特的跳频模式将其分离。

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    Wei H; Yang L-L.; Hanzo L.;

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  • 年度 2005
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  • 正文语种 {"code":"en","name":"English","id":9}
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