Hiroshi Kubo

A Simple Decision-Feedback Block Differential Detection Scheme for DSTBC

For differential space-time block coding (DSTBC), this paper proposes a simple decision-feedback block differential detection (DFBDD) scheme with small computational complexity, in order to improve tracking capability on fast time-varying fading channels. Decisions can be derived directly without computation of metrics in the proposed DFBDD. It can also employ higher-order channel prediction, which needs neither complex trellis search algorithms nor complex channel prediction recursive algorithms. Finally, computer simulation results confirm that the proposed DFBDD with higher-order channel prediction has higher tracking capability at low computational complexity than the conventional block differential detection without channel prediction.

A stable key generation from PUF responses with a Fuzzy Extractor for cryptographic authentications

Physical Unclonable Functions (PUFs) extract inherent characteristics caused by fabrication process variations, and generate unique challenge-response pairs. Some bits of PUF responses are slightly unstable, then the Fuzzy Extractors (FEs) are used to correct the error bits. This paper proposes the new soft-decision FEs considering the instability caused by voltage fluctuation. We applied this method to our novel RG-DTM PUF fabricated by 0.18 μm CMOS technology. It was demonstrated that the block error rate is reduced to 1/10 compared to the conventional soft-decision FE.

A Multiple-Symbol Differential Detection Based on Channel Prediction for Fast Time-Varying Fading

This paper discusses a generalized concept of multiple-symbol differential detection (MDD) and analytically derives weight parameters based on channel prediction for MDD on fast time-varying channels. At first, this paper shows that adaptive maximum-likelihood sequence estimation employing per-survivor processing (PSP-MLSE) with a single channel tap is similar concept to MDD. Next, the weight parameters for MDD are derived according to the channel estimation of PSP-MLSE based on a high order channel prediction. Finally, computer simulation confirms that MDD with the analytically derived parameters mitigates floor of bit error rate (BER) on fast time-varying fading channels without channel state information.

Experimental evaluation of a parallel blind demodulator combined with a Reed-Solomon decoder in the presence of intersymbol interference

This paper evaluates a parallel blind demodulator combined with a Reed-Solomon (RS) decoder in the presence of intersymbol interference (ISI) by means of hardware experiments. Our target systems are point to multi-point (P-MP) communication systems for business use, of which bit rates in the air are 9.6 kbit/s. In such narrow frequency band systems, fast time-varying fading is a serious problem. The implemented parallel blind demodulator employs adaptive maximum-likelihood sequence estimation with per-survivor processing (PSP-MLSE), and the RS code is used for a forward error correction (FEC) code. Finally, experimental results confirm that the parallel blind demodulator combined with the RS decoder achieves excellent BER performance.