Interference suppression and diversity exploitation for multiantenna CDMA with ultra-low complexity receivers
Interference suppression and diversity exploitation for multiantenna CDMA with ultra-low complexity receivers
复制标题
具有超低复杂度接收机的多天线 CDMA 的干扰抑制和分集开发
DOI：
10.1109/tsp.2005.851141
复制
发表时间：
2005
影响因子：
5.4
通讯作者：
K. N. Modi
中科院分区：
文献类型：
--
作者：
D. Reynolds;Xiaodong Wang;K. N. Modi
在多天线、多径码分多址(CDMA)系统中，我们考虑了用于干扰抑制和分集利用的发射机预编码。接收机被限制在没有信道状态信息(CSI)的匹配滤波检测或基于接收机的多用户检测。我们首先为平坦衰落场景开发预编码器，在这种场景中，发射机可以获得完美的下行链路信道信息。我们表明，即使对于非正交扩频码，完全发射天线分集也是可以实现的，尽管我们遭受了信噪比损失，这是扩频码互相关的简单函数。对于发射机具有部分信道信息的情况，我们还开发了预编码器，这些信息被建模为条件信道相关矩阵的知识，并将它们应用于Jake的衰落模型。最后，我们证明了平坦衰落的预编码方法可以被改进用于多径衰落，当与预分集合并一起使用时，可以充分利用多径分集。总而言之，我们表明，当移动单元的计算复杂性最小是优先事项时，发射机预编码提供了基于接收机的多用户信号处理的合理替代方案。
We consider transmitter precoding for interference suppression and diversity exploitation for multiantenna, multipath code division multiple access (CDMA). The receivers are constrained to matched filter detection without channel state information (CSI) or receiver-based multiuser detection. We first develop precoders for flat-fading scenarios where perfect downlink channel information is available at the transmitter. We show that full transmit antenna diversity is achievable, even for nonorthogonal spreading codes, although we suffer an SNR loss that is a simple function of the spreading code crosscorrelations. We also develop precoders for cases in which the transmitter has partial channel information, which is modeled as knowledge of conditional channel correlation matrices, and we apply them to Jakes' fading model. Finally, we show that the precoding approach for flat fading can be modified for multipath fading to fully exploit multipath diversity when used in conjunction with prerake diversity combining. We show, in summary, that transmitter precoding offers a reasonable alternative to receiver-based multiuser signal processing when minimizing computational complexity at the mobile unit is a priority.