Nippon Hoso' Kyokai

Nhk Engineering System, Inc.

Other

Kabushikikaisha Kenwood

Kazuhiko Shibuya

Yutaka Tanaka

Taiji Nishizawa

Taiichiro Kurita

Junji Kumada

Minoru Honda

Yuichi Iwadate

Susumu Saito

Shigeyuki Itoh

Masayuki Takada

Tomohiro Saito

Akinori Hashimoto

Yoshinori Izumi

Seiichi Gohshi

Hisakazu Katoh

Kazumasa Enami

Kenichi Tsuchida

Isao Kondo

Fumiaki Minematsu

Makoto Okui

Ryoichi Yajima

Haruo Okuda

Hiroaki Miyasaka

Yoshikazu Narikiyo

Shingo Asakura

Akihiko Satou

Madoka Honda

Tomoaki Takeuchi

Kenichi Murayama

Masahiro Okano

Takuya Shitomi

Kenichi Shiraishi

Shoji Tanaka

Akihiro Horii

Shoichi Suzuki

Yoshio Takeuchi

Kaoru Watanabe

Shoji Matsuda

Soichi Shinjo

Toshihiro Nomoto

Masaru Kanazawa

Yukihiro Nishida

Toshiyuki Takegahara

Hajime Matsumura

Yasuaki Kanatsugu

Hideki Suganami

Hisakazu Kato

Yoshiharu Hoshino

Kouichi Takano

Makoto Tadenuma

Jun'ichi Ishida

Ichiro Yuyama

Hiroyuki Hamazumi

Masaru Takechi

Toshihiko Susaki

Sumio Yano

Disclosed is a MIMO system including a transmitter and a receiver, in which an overall BER characteristic is improved. The transmitter () maps data, distributed among transmit antennas, onto an IQ plane to generate carrier symbols, and then, applies an inter-polarization interleave processing in a time direction to the carrier symbols between the transmit antennas, to generate OFDM signals. Receiving the OFDM signals, the receiver () demodulates the OFDM signals to generate complex baseband signals, and after that, applies a first deinterleave processing in a time direction to the complex baseband signals to generate time deinterleaved data. Further, the receiver () applies a MIMO separation processing to the time deinterleaved data to generate a plurality of sets of MIMO separated data and applies a second deinterleave processing between the receive antennas to the plurality of sets of MIMO separated data, so as to generate carrier symbols.

Transmitter, receiver, and semiconductor chip

A digital demodulator which will need no absolute phasing circuit is provided. A known-pattern BPSK signal generating circuit generates the same known-pattern BPSK signal as a known-pattern BPSK signal in a received digital modulated wave in synchronism with the known-pattern BPSK signal in the received digital modulated wave, a carrier-reproducing phase error detecting circuit has a phase error table where one of reference phases in a signal point position of a demodulation baseband signal is made a convergence point, a phase error voltage corresponding to a phase error between a phase determined from the signal point position of the demodulation baseband signals and a phase convergence point is sent out, by enable-controlling a carrier-reproducing loop filter according to the known-pattern BPSK signal outputted from the known-pattern BPSK signal generating circuit , the phase error voltage is smoothed, and carrier reproduction is performed while controlling the frequency of a reproduced carrier according to the smoothed output so that the phase in the signal point position coincides with the phase convergence point.

Digital demodulator

Stabilized carrier recovery is achieved even at the time of a low C/N ratio by measuring the phase of a signal and controlling VCO or NCO (Numerical Controlled Oscillator) using only a period having few constellation points. At this time, false lock phenomenon is avoided as follows. That is, relatively short SYNC modulated by an already-known pattern is entered into a modulation wave, VCO or NCO oscillation frequency is swept in a wide range and sweep is stopped at a frequency in which the SYNC can be received, thereby carrying out coarse control AFC. Further, a period having long to some extent, having few constellation points is provided in the modulation wave and then, a difference between the frequency of a received modulated signal and a local oscillation signal of VCO or NCO is obtained in this period. This frequency difference is analyzed according to the phase differential function method, self-correlation function method or count method, and the VCO or NCO is controlled based on this result of analysis.

AFC circuit, carrier recovery circuit and receiver device capable of regenerating a carrier reliably even at the time of low C/N ratio

High resolution vertical and horizontal components of a high definition video signal are combined with a standard broadcast system video signal, such as the NTSC system, in which high frequency horizontal resolution components are sampled and used to modulate at least a first sub-carrier signal. The first sub-carrier is frequency interleaved onto the standard broadcast signal. Vertical high resolution components are time compressed and time division multiplexed onto top and bottom portions of the standard broadcast signal. The modified broadcast signal can be decoded by a standard receiver to display a standard resolution video image, while receivers designed to decode the modified signal can time division demultiplex the vertical high resolution components and demodulate the horizontal high resolution components, combine these components with the standard components, and generate a high definition video image.

Receiver and channel compatible encoding/decoding system for high

A method and system for multiplexing additional audio information in the form of pulse code modulation (PCM) audio signals onto a television signal. The PCM audio signal is time multiplexed into scanning retrace intervals of the video signal. At a receiver, the bit error rate of the decoded PCM audio signal is compared with a threshold so as to switch the audio output from the PCM audio signal to a conventional FM demodulated audio signal when the bit error rate exceeds the predetermined threshold. In this way, the benefits of both PCM audio and FM audio can be obtained by utilizing the higher immunity of FM signals in low signal-to-noise ratio environments, while the high fidelity PCM audio signal is utilized when the signal-to-noise ratio environment is relatively high.

Method and system for transmitting and receiving PCM audio signals in

A multiple sub-sampling encoding/decoding system performing interfield and interframe offset sub-sampling of a broad bandwidth television signal. The system compresses the television signal to fit, for example, to the transmission bandwidth of the standard television systems, compensates the transmission characteristics, and achieves the optimal frequency allocation of the modulated transmission signal.

Multiple sub-sampling transmitting/receiving system performing

Growing community of inventors

Tokyo, Japan

Kazuhiko Shibuya