Abstract—In this paper, we present an mmWave multiantenna configured transceiver for Sparse Code Multiple Access (SCMA) schemes implemented in an Orthogonal Time Frequency Space (OTFS) system. Our proposed system introduces a 6-D hyperchaotic mapping system-aided encryption algorithm to enhance physical layer security (PLS). Additionally, Turbo, Low-Density Parity Check (LDPC) and repeat and accumulate (RA) channel coding, modified form of Delay-Doppler (DD)-domain SCMA codeword allocation, Log-domain Message Passing Algorithm (Log-MPA)-based SCMA decoding, Cholesky Decomposition-Based ZF (CD-ZF) and Minimum Mean Square Error (MMSE) signal detection schemes are introduced for achieving improved Bit Error Rate (BER). The numerical results demonstrate the effectiveness of the proposed system in terms of PLS enhancement with low correlation coefficients (15.54%, 16.00%, 26.11%, 22.39%, 19.45%, and 18.68% for Users 1, 2, 3, 4, 5, and 6, respectively) on synthetically generated binary data transmission. Our system achieves a Complementary Cumulative Distribution Function (CCDF) of Peak-to-Average Power Ratio (PAPR) of 6.61 dB at its 0.1% probability level. The six users achieve a BER of 1×10^-4 at signal-to-noise ratios (SNRs) of 6.5 dB, 15 dB, 8.5 dB, 6.5 dB, 9.5 dB, and 8.5 dB underutilization of turbo channel coding and MMSE signal detection schemes. In the case of turbo channel coding and CD-ZF signal detection schemes, the BER performance for all six users approaches zero for SNR values ranging from 0 dB to 20 dB.