SHANNON-THEORETIC APPROACH TO A GAUSSIAN CELLULAR MULTIPLE-ACCESS CHANNEL
SHANNON-THEORETIC APPROACH TO A GAUSSIAN CELLULAR MULTIPLE-ACCESS CHANNEL
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DOI：
10.1109/18.340450
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发表时间：
1994-11-01
影响因子：
2.5
通讯作者：
WYNER, AD
中科院分区：
文献类型：
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作者：
WYNER, AD
我们得到一个非常简单的蜂窝多址系统香农理论的限制。 在我们的模型中，给定小区站点处的接收信号是从该小区内发送的信号之和加上因子alpha（0小于或等于alpha小于或等于1）乘以从相邻小区发送的信号之和加上环境高斯噪声。 虽然这个简单的模型几乎不现实，但它仍然有足够的肉，使结果产生相当深入的真实的系统的工作。 我们考虑一维线性蜂窝阵列和熟悉的二维六边形蜂窝图案。 离散时间信道是无记忆的。 我们假设在一维情况下，N个连续的小区具有活动的发射机，并且在二维情况下，N2个连续的小区具有活动的发射机。 每个细胞有K个发射器。 我们的大多数结果是在N ->无穷大的极限情况下得到的。 （1）定义C（N）、C（N）分别为在一维和二维情况下在通常香农理论意义上的每个发射机的最大可达速率（假设所有信号被联合解码）。 我们找到了lim（N --> infinity）C（N）和lim（N --> infinity C（N）的表达式。 (2)随着干扰参数α从0增加，C（N）和C（N）根据信噪比是小于还是大于1而增加或减小。 (3)在小区内使用TDMA可获得最佳性能，但对于相邻小区使用TDMA显然是次优的。 (4)我们提出了一个方案，它不需要联合解码的所有用户，并且在许多情况下，接近最优。
We obtain Shannon-theoretic limits for a very simple cellular multiple-access system. In our model the received signal at a given cell site is the sum of the signals transmitted from within that cell plus a factor alpha (0 less-than-or-equal-to alpha less-than-or-equal-to 1) times the sum of the signals transmitted from the adjacent cells plus ambient Gaussian noise. Although this simple model is scarcely realistic, it nevertheless has enough meat so that the results yield considerable insight into the workings of real systems. We consider both a one-dimensional linear cellular array and the familiar two-dimensional hexagonal cellular pattern. The discrete-time channel is memoryless. We assume that N contiguous cells have active transmitters in the one-dimensional case, and that N2 contiguous cells have active transmitters in the two-dimensional case. There are K transmitters per cell. Most of our results are obtained for the limiting case as N --> infinity. The results include the following: (1) Define C(N), C(N) as the largest achievable rate per transmitter in the usual Shannon-theoretic sense in the one-and two-dimensional cases, respectively (assuming that all signals are jointly decoded). We find expressions for lim(N --> infinity) C(N) and lim(N --> infinity C(N). (2) As the interference parameter alpha increases from 0, C(N) and C(N) increase or decrease according to whether the signal-to-noise ratio is less than or greater than unity. (3) Optimal performance is attainable using TDMA within the cell, but using TDMA for adjacent cells is distinctly suboptimal. (4) We suggest a scheme which does not require joint decoding of all the users, and is, in many cases, close to optimal.