论文标题
用于随机计算的低成本随机数发生器
Low-cost Stochastic Number Generators for Stochastic Computing
论文作者
论文摘要
随机一元计算提供低区域电路。但是，这些电路中所需的地区消耗随机数发生器（SNG）可能会降低其整体增益，尤其是在需要几个SNG的情况下。我们通过在几个SNG中共享一个线性反馈偏移寄存器（LFSR）的排列输出来提出面积效率的SNG。由于没有硬件开销，因此提出的体系结构生成具有最小随机计算相关性（SCC）的随机位流。与先前工作中提出的循环方法相比，当两个SNG之间共享10位LFSR时，我们的方法会产生随机位流，平均SCC降低67％。为了概括我们的方法，我们提出了一种算法，以找到N位LFSR的一组M置换术（N> m> 2）。当n增加n增加时，查找精确最小SCC的置换空间会迅速生长，并且使用精确计算的成对SCC值（对于n> 9）执行搜索算法很难。我们提出了一个相似性函数，可以在建议的搜索算法中使用，以快速找到一组置换量，其SCC值接近最小值。我们评估了几种应用的方法。结果表明，与先前的工作相比，它在相同（甚至较低）区域的情况下达到了较低的MSE。此外，基于模拟结果，我们表明，用加权二进制发电机替换SNG电路的比较器组件可以减少SCC。
Stochastic unary computing provides low-area circuits. However, the required area consuming stochastic number generators (SNGs) in these circuits can diminish their overall gain in area, particularly if several SNGs are required. We propose area-efficient SNGs by sharing the permuted output of one linear feedback shift register (LFSR) among several SNGs. With no hardware overhead, the proposed architecture generates stochastic bit streams with minimum stochastic computing correlation (SCC). Compared to the circular shifting approach presented in prior work, our approach produces stochastic bit streams with 67% less average SCC when a 10-bit LFSR is shared between two SNGs. To generalize our approach, we propose an algorithm to find a set of m permutations (n>m>2) with minimum pairwise SCC, for an n-bit LFSR. The search space for finding permutations with exact minimum SCC grows rapidly when n increases and it is intractable to perform a search algorithm using accurately calculated pairwise SCC values, for n>9. We propose a similarity function that can be used in the proposed search algorithm to quickly find a set of permutations with SCC values close to the minimum one. We evaluated our approach for several applications. The results show that, compared to prior work, it achieves lower MSE with the same (or even lower) area. Additionally, based on simulation results, we show that replacing the comparator component of an SNG circuit with a weighted binary generator can reduce SCC.
