Kabushiki Kaisha Toyota Chuo Kenkyusho

Nippondenso Co., Ltd.

Tsutayuki Shibata

Noriyoshi Suzuki

Chisato Endo

Hiroaki Hayashi

Hisanori Uda

Tomohisa Harada

Masanori Miyashita

Yoshimi Kitazumi

Mitoshi Fujimoto

Nobuo Itoh

Naoyuki Yamada

A receiver configured to receive a plurality of signals k (k=1, 2, . . . , M) allocated in a first frequency band. The receiver includes a frequency conversion section for reallocating the signals k in a second frequency band for sampling by a single AD converter at a sampling frequency fsuch that digital data of the sampled signals k are obtained in a third frequency band extending from zero Hz to a frequency represented by f/2; and a signal extraction section for extracting a target base band signal k from the digital data obtained by the AD conversion section. The frequency conversion section performs the reallocation in such a manner that at least a frequency represented by Jf/2 (J is an integer) is located between the frequencies of at least two of the signals k and that the sampled signals do not overlap.

Receiver apparatus

An adaptive communication apparatus for use in a multicarrier transmission system in which data sequence to be transmitted is divided into a plurality of data sequences, and these data sequences are converted into a high-frequency signal including a plurality of carriers allocated different frequencies and radio-transmitted in parallel. In the adaptive communication apparatus, a received high-frequency signal is separated into a plurality of carriers by a wave separator. The frequency characteristic of the received high-frequency signal is corrected by a frequency characteristic compensation unit. The frequency characteristic compensation unit is controlled by a controller through use of the high-frequency signal subjected to signal processing by the frequency characteristic compensation unit and the wave separator. The high-frequency signal thus processed by the frequency characteristic compensation unit and the wave separator is demodulated by a demodulator in order to output a plurality of data sequences corresponding to the respective carriers. The original data is reproduced by a parallel-to-serial converter from the plurality of data sequences corresponding to the respective carriers.

Adaptive communication apparatus

A differential detector (2) reproduces a spreading code (S2) of a received signal (S1). A digital correlator (4) calculates a correlation value between the reproduced spreading code (S2) and a reference spreading code (S3) by collating bit by bit. The timing when the correlation value exceeds a predetermined threshold value (D2) means that the reproduced spreading code (S2) and the reference spreading code (S3) match in phase. A phase of the reproduced spreading code (S2), or a phase of the received signal (S1), is discriminated at that timing. A multiplier (8) outputs a modulated signal (S6) by multiplying the received signal (S1) bit by bit in phase by a spreading code (S5) which has the same code as the reference spreading code (S3). In result, a spreading code with an accurate code sequence and phase is obtained for despreading, and theoretical process-gain is obtained.

Receiver for spread spectrum communication

Growing community of inventors

Aichi-ken, Japan

Tsutayuki Shibata