あらまし 次世代の移動無線通信では高速パケットアクセス技術が求められている.アクセス技術としてマルチ キャリア CDMA (MC-CDMA)が注目されている.そして,高速パケット伝送技術として自動再送要求(ARQ)に誤り 訂正符号化を組み合わせた Hybrid ARQ(HARQ)が検討されている.最近,誤り訂正符号として比較的少ない復号演 算量で強力な誤り訂正能力を有するLDPC符号の研究が盛んに行われている.LDPC符号化マルチコードMC-CDMA の平均ビット誤り率(BER)特性は直交拡散コード間のコード間干渉(ICI)の影響により劣化してしまう.ICI を低減す る技術として周波数領域適応干渉キャンセラ(FDAIC)が提案されている.本論文では,LDPC 符号語内適応変調およ び FDAIC によるスループット向上について検討している.周波数選択性フェージング環境下でのスループ...

Mapping rearrangement (MaRe) for the hybrid ARQ (HARQ) based on the parallel concatenated trellis coded modulation (PCTCM) is analyzed. We demonstrate that the performance of the PCTCM receiver is intrinsically limited by the MaRe design and we propose a new mapping scheme to fit the structure of PCTCM transceivers. Depending on the HARQ scenarios, the proposed scheme offers gains between 0.1 a...

Karl-Dirk KAMMEYER and Dirk NIKOLAI Univ. of Bremen, Dept. of Telecommunications1 , P.O. Box 33 04 40, D-28334 Bremen, Germany Tel.: ++(49)-421/218-2453, Fax: ++(49)-421/218-3341, E-mail: [email protected] Abstract2: In this paper, we present a novel transmission scheme with application to Direct Sequence Code Division Multiple Access (DSCDMA) combining M -ary orthogonal and PSK modula...

Light shaping techniques based on phase-only modulation o er multiple advantages over amplitude modulation. This review examines and compares the merits of two phase modulation techniques; phase-only computer generated holography and Generalized Phase Contrast (GPC). Both techniques are brie y presented while recent developments in GPC will also be covered. Furthermore, novel hybrid schemes tha...

We propose a technique for recovering the position and depth of pronuclei of human zygotes, from z-stacks acquired using Hoffman Modulation Contrast microscopy. We use Local Binary Pattern features for describing local texture, and integrate information from multiple neighboring areas of the stack, including those where the object to be detected would appear defocused; interestingly, such defoc...

This paper presents a hybrid watermarking technique which mixes additive and multiplicative watermark embedding with emphasis on its robustness versus the imperceptibility of the watermark. The embedding is performed in six wavelet sub-bands using independently three embedding equations and two parameters to modulate the embedding strength for multiplicative and additive embedding. The watermar...

Audio-rate modulation of the parameters of physical models is investigated. For example, the resonance frequency of a simple resonator can be modulated smoothly at an audio rate to produce a brighter tone. As with traditional frequency modulation (FM) signal models, complex spectra can be produced through variation of the resonator’s frequency. It is possible to create such hybrid physical/sign...

We propose dynamic modulation of a hybrid plasmonic-photonic crystal nanocavity using monochromatic coherent acoustic phonons formed by ultrahigh-frequency surface acoustic waves (SAWs) to achieve strong optomechanical interaction. The crystal nanocavity used in this study consisted of a defective photonic crystal beam coupled to a metal surface with a nanoscale air gap in between and provided ...