DS-CDMA Systems Using -Level Sequences: Coding Map Theory
DS-CDMA Systems Using -Level Sequences: Coding Map Theory
复制标题
使用级序列的 DS-CDMA 系统：编码映射理论
DOI：
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发表时间：
1997
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通讯作者：
G. Mazzini
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作者：
G. Mazzini
DS-CDMA 系统考虑具有复杂扩频映射的 GF(·) 序列，参考同步性水平不断提高的三种不同环境。对于所有环境，性能评估都是通过需要扩展序列规范的确定性方法以及基于扩展序列遍历性假设的统计推导来导出的，以便给出封闭形式的性能理论。通过零均值复杂代码映射，针对所有环境计算最佳映射设计标准，并通过多次数值测试进行验证。已在低同步环境中证明了关于序列级别的性能不变性，其中所提出的序列提供了更好的性能。被评估。多相扩频码在（7）中进行了讨论和表征，而在（8）中则提出了基于不可约多项式的具有渐近最优韦尔奇约束序列的族。在 (9) 中可以找到一组与 SSMA 系统相关的有趣正交序列。可能的序列集是基于序列的，关于序列生成的本原多项式以及不同生成域阶之间的关系的有趣论文分别在（10）和（11）中找到。在本文中，考虑了由基于 GF prime 的序列形成的非二进制码类，并通过假设三种不同的环境作为发射机同步性的函数来导出其系统性能影响，其中发射机同步性相对于延迟（由于传播和序列移位偏移）和相对相位（由于本地载波振荡器），定义为从第一个发射机到第一个接收机。这些环境称为异步，其中延迟和载波相位都是独立的，伪同步，其中延迟是确定性和协调的：
GF( ) sequences with complex spreading map- ping are considered for DS-CDMA systems by referring to three different environments with increasing synchronicity lev- els. For all environments, performance evaluation is derived both with a deterministic approach requiring spreading sequence specification, and with a statistical derivation, based on the assumption of spreading sequence ergodicity, in order to give closed-form performance theory. The optimal mapping design criterion, through zero-mean complex code mapping, is computed for all environments and validated through several numerical tests. Performance invariance, with respect to sequence levels, has been demonstrated for low synchronous environments, where the proposed sequence gives better performance. are evaluated. Multiphase spreading codes are discussed and characterized in (7), while a family with an asymptotically op- timal Welch bound sequence, based on irreducible polynomials over is presented in (8). A set of interesting orthogonal sequences with relative application to SSMA systems can be found in (9). A possible sequence set is based on sequences, and interesting papers on primitive polynomials for sequence generation and relationships between different generation field orders are found in (10) and (11), respectively. In this paper, the nonbinary code class formed by sequences built on GF prime, is taken into account, and its system performance impact is derived by assuming three different environments as a function of transmitter synchronic- ity with respect to delays (due to propagation and sequence shift offset), and to relative phases (due to local carrier oscillator), defined from the th transmitter to the th receiver. These environments are called asynchronous, where both delays and carrier phases are independent, pseudosynchronous, where delays are deterministic and coordinate: