| 糸井三由希 | 1151012: M, 2回目発表 | 鹿野清宏, 杉本謙二, 猿渡洋 |
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title: Blind Speech Extraction for Non-Audible Murmur Speech with Speaker's Movement Noise
abstract: In this research, we address an improved method of noise reduction used in multichannel Non-Audible Murmur (NAM) based on blind source separation. Recently, speech processing with NAM has been proposed for applying versatile speech interface into quiet environments where we hesitate to utter. NAM is a very soft whispered voice signal detected with the NAM microphone, which is one of the body-conductive microphone. The detected NAM signal always suffers from nonstationary noise caused by speaker's movement because it changes the setting condition of the NAM microphone. In order to reduce the noise signal, blind noise reduction using stereo NAM signals detected with two NAM microphones has been proposed by some of the authors. In this paper, we aim to achieve further improvement in the noise reduction ability by changing the noise estimation and postprocessing algorithms to enhance the target NAM signal. In addition, we evaluate the application of recording the NAM signals with various types of microphones. language of the presentation: Japanese 発表題目: ユーザ動作に伴う雑音を含む非可聴つぶやき音声におけるブラインド音声抽出 発表概要: 本研究では、多チャネル非可聴つぶやき（Non-Audible Murmur: NAM） における、ブラインド音源分離に基づく雑音抑圧の改善について論じる． 発話行為が躊躇されるような静寂な環境においても音声インターフェイス を可能とするため、NAMを用いた音声処理が提案されている． NAMは非常に小さな無声音声信号であり，体表に圧着させるNAMマイクロホン というものによって収録される．そのため，ユーザが動くとNAMマイクロホン の圧着状況が変動し，常に非定常な雑音が混入する． この雑音を抑圧するために，2つのNAMマイクロホンによって収録される ステレオNAM信号を用いた，ブラインド雑音抑圧法が著者らによって提案されて いる。本報告では，NAM信号を強調するために、雑音推定アルゴリズムや 後段処理を変えることで，さらなる雑音抑圧性能の向上を達成する． また，各種の異なるマイクロホンを用いて得られた複数NAM信号の 応用可能性についても評価を行う． | ||
| REINOSO CHISAGUANO DIEGO JAVIER | 1151208: M, 2回目発表 | 岡田実, 杉本謙二, 東野武史 |
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title: Computational cost reduction of the detection process of MIMO-OFDM with ESPAR antenna receiver
abstract: MIMO-OFDM with ESPAR(Electronically Steerable Passive Array Radiator) antenna receiver can obtain additional diversity gain, improving the bit error rate performance. This scheme uses the V-BLAST(Vertical-Bell Laboratories Layered Space-Time) algorithm for the detection process. However, due to the big size of the channel matrix, the computational cost is too high to be implemented. Using a MMSE sparse-SQRD algorithm for the detection process the computational cost can be considerably reduced. In this presentation, a sub-matrix divided MMSE sparse-SQRD algorithm for the detection process is introduced. The computational cost analysis and simulation results show that in average the proposed scheme can further reduce the computational cost and achieve a complexity comparable to the common MIMO-OFDM detection schemes. language of the presentation: English | ||
| 石黒剛大 | 1161003: D, 中間発表 | 岡田実, 杉本謙二, 東野武史 |
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title: Receiver with Nonlinearity Compensation for Broadband Satellite
Communication Systems
abstract: In this research, a nonlinearity compensation scheme for satellite receiver, of which nonlinear amplifier like TWTA (Traveling Wave Tube Amplifier) is used as satellite transponder, has been studied. First, a nonlinearity compensation scheme for carrier superposed satellite communication is proposed and shown that the scheme is effective in high CNR (Carrier-to-Noise power Ratio) condition. Then, the scheme is applied to compensate nonlinear distortion of satellite communication with multi-level modulation signals. Here, the nonlinearity compensation scheme is optimized by considering the effect of bandwidth limitation filters on transmitted pulse shape which is inserted in earth station transmitter, satellite transponder, and earth station receiver. Results of simulation show that with proposal scheme, it is possible to improve the degradation of error rate performance caused by waveform distortion at nonlinear amplifier. language of the presentation: Japanese 発表題目: ブロードバンド衛星通信システムにおける非線形補償機能を有する受信機 発表概要: 本研究では，衛星中継器に TWTA (Traveling Wave Tube Amplifier) などの非線形増幅器を含む衛星通信における，受信側での非線形補償方 式について検討を行う．まず，信号重畳方式を採用した衛星通信 での非線形補償方式の提案を行い、本方式が高い CN 比の環境でより効果を 示すことを明らかにした。次に、提案方式を多値変調信号 を用いた衛星通信における非線形性ひずみ補償に適用する。ここでは、 地球局送信機、衛星中継器、および受信機の帯域制限フィルタおよび 伝送パルス波形の影響を考慮に入れ、非線形補償方式の最適化を行う． 計算機シミュレーションの結果，提案手法を用いることで，非線形増幅器の波形ひず みによる誤り率特性の劣化を大幅に改善できることを明らかにした． | ||