On the achievable throughput of a multiantenna Gaussian broadcast channel
On the achievable throughput of a multiantenna Gaussian broadcast channel
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DOI：
10.1109/tit.2003.813523
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发表时间：
2003-07-01
影响因子：
2.5
通讯作者：
Shamai, S
中科院分区：
文献类型：
--
作者：
Caire, G;Shamai, S
考虑到发射机处的带有单恒星接收器和T天线的高斯广播频道（GBC）。发射器和接收器都对频道都有完美的了解。尽管它显然很简单，但通常是一个非核层广播渠道（BC），因为该模型尚不完全知道。对于两用户的情况，我们发现了Marton地区的特殊情况，可以实现最佳总和。 -rate（吞吐量）。简而言之，发射器将通道分解为两个干扰通道，其中干扰是由其他用户信号引起的。用户是连续编码的，因此第二个用户的编码基于对第一个用户引起的干扰的非原因知识。串扰参数得到了优化，以使总吞吐量是最大的，而且令人惊讶的是，这在所有可能的策略中都非常最佳（不仅相对于Marton的可实现区域），对于R> 2用户，我们发现了某种程度上基于订购和连续编码用户的Marton区域的更简单选择。对于给定订单中的每个用户i，用户j> i引起的干扰是通过发射器上的零强制消除的，而用户j <i引起的干扰是通过编码非本质已知的干扰来考虑的。在某些轻度条件下，发现该方案是吞吐量的。对于高和低信噪比（SNR）的ASPMTotottottion。我们通过为独立的瑞利褪色中简化的零强度方案的千古吞吐提供了一些数值结果来得出结论。
A Gaussian broadcast channel (GBC) with r single-antenna receivers and t antennas at the transmitter is considered. Both transmitter and receivers have perfect knowledge of the channel. Despite its apparent simplicity, this model is, in general, a nondegraded broadcast channel (BC), for-which the capacity region is not fully known.For the two-user case, we find a special case of Marton's region that achieves optimal sum-rate (throughput). In brief, the transmitter decomposes the channel into two interference channels, where interference is caused by the other user signal. Users are successively encoded, such that encoding of the second user is based on the noncausal knowledge of the interference caused by the first user. The crosstalk parameters are optimized such that the overall throughput is maximum and, surprisingly, this is shown to be optimal over all possible strategies (not only with respect to Marton's achievable region).For the case of r > 2 users, we find a somewhat simpler choice of Marton's region based on ordering and successively encoding the users. For each user i in the given ordering, the interference caused by users j > i is eliminated by zero forcing at the transmitter, while interference caused by users j < i is taken into account by coding for noncausally known interference. Under certain mild conditions, this scheme is found to be throughput-wise. asympmtotically optimal for both high and low signal-to-noise ratio (SNR).We conclude by providing some numerical results for the ergodic throughput of the simplified zero-forcing scheme in independent Rayleigh fading.