Sho Kuroda’s research while affiliated with Yamaguchi University and other places

In recent years, indoor localisation based on channel state information (CSI) fingerprint has been actively researched because of the rapid growth of the Internet of Things (IoT). In addition, various deep learning (DL) methods such as deep neural networks (DNN) and convolutional neural networks (CNN) have been widely discussed for the indoor localisation. The CSI‐fingerprint can be produced by continuous and quantised values. For the CSI‐fingerprint using quantised values, good performance is achieved. However, since quantised data for the optimal level has not been sufficiently discussed, the best performance of quantisation is not indicated. Therefore, in this paper, we propose an effective quantised CSI‐fingerprint for DL‐based indoor localisation.

In cooperative systems for multi-antenna techniques, multiple-input multiple-output (MIMO) is essential to enhance the system capacity. For the transmission technique of MIMO systems, there is the combination of the space division multiplexing (SD) and the spatial modulation (SM), and the bit error rate (BER) performance is improved by using the channel ranking QR decomposition with M algorithm maximum likelihood detection (CR-QRM-MLD). And then, the transmission for the phase rotation SM on-off keying (PR-SM-OOK) and the rectangular SD-8QAM is also effective by using the CR-QRM-MLD with the simultaneous and separated searches. On the other hand, there are several assignments of the constellation for the 8QAM, but they are not evaluated in the SD-SM-MIMO. Therefore, in this paper, we propose the combination of the PR-SM-OOK and the rectangular, cross, octagonal SD-8QAMs for MIMO systems.

A set consisting of K subsets of M sequences of length L is called a complementary sequence set expressed by A(L, K, M), if the sum of the out-of-phase aperiodic autocorrelation functions of the sequences within a subset and the sum of the cross-correlation functions between the corresponding sequences in any two subsets are zero at any phase shift. Suehiro et al. first proposed complementary set A(Nⁿ, N, N) where N and n are positive integers greater than or equal to 2. Recently, several complementary sets related to Suehiro's construction, such as N being a power of a prime number, have been proposed. However, there is no discussion about their inclusion relation and properties of sequences. This paper rigorously formulates and investigates the (generalized) logic functions of the complementary sets by Suehiro et al. in order to understand its construction method and the properties of sequences. As a result, it is shown that there exists a case where the logic function is bent when n is even. This means that each series can be guaranteed to have pseudo-random properties to some extent. In other words, it means that the complementary set can be successfully applied to communication on fluctuating channels. The logic functions also allow simplification of sequence generators and their matched filters.