QoS-aware NOMA with Sequence Block Compressed Sensing Multiuser Detection

Non-orthogonal multiple access (NOMA) with compressed sensing based multiuser detection (CSMUD) is a promising candidate to enable massive connectivity for the massive machine type communication (mMTC) in 5G. In this paper, we have proposed three approaches to improve the performance and enable differentiation in the quality of service (QoS) among the mMTC devices in NOMA with sequence block CSMUD. First, a repeated-transmission scheme with spreading diversity is proposed which enhances the performance of all sensor nodes. Secondly, a QoS-aware sequence block allocation scheme is proposed to differentiate QoS in mMTC by assigning the low correlated sequence blocks to the high priority nodes. Lastly, the above two approaches are combined to propose a QoS-aware repeated-transmission scheme which not only increases the QoS differentiation but also achieves a significant gain in SNR of both high and low priority nodes. A QoS-aware group orthogonal matching pursuit based algorithm is designed to jointly detect and estimate the data. It is shown that the proposed repeated-transmission with spreading diversity scheme reduces the detection error rate (DER) and the bit error rate (BER) by more than two order of magnitude at SNR = 10 dB. Using the QoS-aware sequence block allocation scheme, it is shown that a gain of more than half a magnitude in DER and BER is achieved at SNR = 13 dB. The combined QoS-aware repeated-transmission scheme achieves a gain of at least 12 dB at BER = 10
^-4
for the high priority nodes as well as a gain of at least 6 dB for the low priority nodes.