标题： 时变无线网络中的调度与码字长度优化 显示英文标题

标题： Scheduling and Codeword Length Optimization in Time Varying Wireless Networks

摘要： 在本文中，考虑了一个下行链路场景，其中单天线基站通过时间相关的衰落信道与K个单天线用户进行通信。假设每个接收器都能完美地知道信道状态信息，而衰落过程的统计特性以及每个帧开始时的衰落增益已知于发射器。通过评估时间相关衰落信道的随机编码错误指数，表明存在一个最优码字长度，可最大化吞吐量。使用固定长度码字和可变长度码字，研究了传统调度的吞吐量，该调度向信噪比最大的用户发送。尽管优化码字长度可以提高性能，但研究表明，使用传统调度时，可实现的吞吐量与系统最大可能吞吐量之间的差距随着K趋于无穷大而趋于无穷大。提出了一种简单的调度方法，同时考虑了信噪比和信道时间变化。研究表明，通过使用这种调度，可实现的吞吐量与系统最大吞吐量之间的差距趋近于零。 显示英文摘要

摘要： In this paper, a downlink scenario in which a single-antenna base station communicates with K single antenna users, over a time-correlated fading channel, is considered. It is assumed that channel state information is perfectly known at each receiver, while the statistical characteristics of the fading process and the fading gain at the beginning of each frame are known to the transmitter. By evaluating the random coding error exponent of the time-correlated fading channel, it is shown that there is an optimal codeword length which maximizes the throughput. The throughput of the conventional scheduling that transmits to the user with the maximum signal to noise ratio is examined using both fixed length codewords and variable length codewords. Although optimizing the codeword length improves the performance, it is shown that using the conventional scheduling, the gap between the achievable throughput and the maximum possible throughput of the system tends to infinity as K goes to infinity. A simple scheduling that considers both the signal to noise ratio and the channel time variation is proposed. It is shown that by using this scheduling, the gap between the achievable throughput and the maximum throughput of the system approaches zero.