We consider the coding problem in the Stiefel manifold with chordal distance. After considering various low-dimensional instances of this problem, we use Rankin's bounds on spherical codes to prove upper bounds on the minimum distance of a Stiefel code, and then we construct several examples of codes that achieve equality in these bounds.

翻译：本文研究了具有弦距离的Stiefel流形中的编码问题。在分析了该问题的若干低维实例后，我们利用Rankin球面码界证明了Stiefel码最小距离的上界，随后构造了多组达到该界等号情形的编码实例。