Capacity per Unit-Energy of Gaussian Many-Access Channels
Capacity per Unit-Energy of Gaussian Many-Access Channels
复制标题
高斯多址信道单位能量容量
DOI：
10.1109/isit.2019.8849751
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
T. Koch
中科院分区：
文献类型：
--
作者：
Jithin Ravi;T. Koch
我们考虑一个高斯多址信道，其中发射器的数量随着块长度n的增长而增长。对于这种设置，分析了每单位能量可以可靠传输的最大位数。我们证明了如果用户数量严格大于n/log n的阶数，那么用户不能达到任何正的单位能量速率。相反，如果用户数量严格小于n/log n的阶数，则每个用户可以通过时分多址等正交接入方案实现单位能量单用户容量(log e)/N0（其中N0/2为噪声功率）。我们进一步证明了正交码本可以是严格次优的，当用户数量有界时，正交码本可以达到单位能量容量。
We consider a Gaussian multiple-access channel where the number of transmitters grows with the blocklength n. For this setup, the maximum number of bits that can be transmitted reliably per unit-energy is analyzed. We show that if the number of users is of an order strictly above n/log n, then the users cannot achieve any positive rate per unit-energy. In contrast, if the number of users is of order strictly below n/log n, then each user can achieve the single-user capacity per unit-energy (log e)/N0 (where N0/2 is the noise power) by using an orthogonal access scheme such as time division multiple access. We further demonstrate that orthogonal codebooks, which achieve the capacity per unit-energy when the number of users is bounded, can be strictly suboptimal.