Chapter 3: On Symbol-Pair Distances of Constacyclic Codes of Length $ 4p^s$ over $\mathbb{F}_{p^m}$

In this Chapter, we obtain the symbol-pair distances of $\lambda$-constacyclic codes of length $4p^s$ over $\mathbb{F}_{p^m}$ for Cases 1, 2, and 3 of Table 1. Also we identify all symbol-pair MDS constacyclic codes of length $4p^s$ among them. We organize the rest of the Chapter in the following manner. In Section 3.2, we give computational procedures to determine the symbol-pair distances of $\lambda$-constacyclic codes of length $4p^s$ over $\mathbb{F}_{p^m}$ for Cases 1, 2, and 3 of Table 1. And in Section 3.3, we explore all symbol-pair MDS codes of length $4p^s$ among them and give some examples of MDS symbol-pair codes.