A class of twisted generalized Reed-Solomon codes
Let š½_q be a finite field of size q and š½_q^* the set of non-zero elements of š½_q. In this paper, we study a class of twisted generalized Reed-Solomon code C_ā(D, k, Ī·, vā)āš½_q^n generated by the following matrix ([ v_1 v_2 ⯠v_n; v_1α_1 v_2α_2 ⯠v_nα_n; ā® ā® ā± ā®; v_1α_1^ā-1 v_2α_2^ā-1 ⯠v_nα_n^ā-1; v_1α_1^ā+1 v_2α_2^ā+1 ⯠v_nα_n^ā+1; ā® ā® ā± ā®; v_1α_1^k-1 v_2α_2^k-1 ⯠v_nα_n^k-1; v_1(α_1^ā+ηα_1^q-2) v_2(α_2^ā+ ηα_2^q-2) ⯠v_n(α_n^ā+ηα_n^q-2) ]) where 0ā¤ā⤠k-1, the evaluation set D={α_1,α_2,āÆ, α_n}āš½_q^*, scaling vector vā=(v_1,v_2,āÆ,v_n)ā (š½_q^*)^n and Ī·āš½_q^*. The minimum distance and dual code of C_ā(D, k, Ī·, vā) will be determined. For the special case ā=k-1, a sufficient and necessary condition for C_k-1(D, k, Ī·, vā) to be self-dual will be given. We will also show that the code is MDS or near-MDS. Moreover, a complete classification when the code is near-MDS or MDS will be presented.
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