公开(公告)号：EP0280161A2

公开(公告)日：1988-08-31

申请号：EP88102241.2

申请日：1988-02-16

Applicant: NEC CORPORATION

Inventor： Ichiyoshi, Osamu

IPC: H01J1/05 ,  H04J4/00

CPC classification number: H04J1/05 ,  H03H17/0213

Abstract: An N-channel FDM signal is converted into complex signals of baseband frequencies (1-6) spaced at intervals equal to frequency Δf. The complex baseband signals are converted first into digital samples (7-9)having a frequency NΔf and then into N parallel digital signals (11). A plurality of first FIR subfilters (17-1 through 17-N) respectively perform filtering on each of the parallel digital signals at frequency Δf to produce a first series of filtered digital signals from each of the first FIR subfilters, and (m - 1) groups of second FIR subfilters respectively perform filtering on each of the parallel digital signals at frequency Δf to produce a second series of filtered digital samples from each of the second FIR subfilters at timing displaced with respect to the first series by a/mΔf, where is an integer ranging from unity to (m - 1) and m is an integer equal to or greater than 2. Outputs of the first FIR subfilters are combined with outputs of the second FIR subfilters to produce N summation outputs at frequency mΔf. An N-point Fast Fourier Transform processor (14) performs fast Fourier transform on the N summation outputs at frequency mΔf to derive digital channels. Because of the oversampling at frequency mΔf, each of the digital channels has a frequency response which can be made flat over the bandwidth Δf.

Abstract translation: N信道FDM信号被转换成以等于频率DELTA f的间隔隔开的基带频率（1-6）的复信号。 复基带信号首先被转换成具有频率N DELTA f的数字样本（7-9），然后转换成N个并行数字信号（11）。 多个第一FIR子滤波器（17-1至17-N）分别对频率DELTA f上的每个并行数字信号执行滤波，以产生来自第一FIR子滤波器中的每一个的第一系列滤波数字信号，并且（m- 1）第二FIR子滤波器组分别在频率DELTA f上对每个并行数字信号执行滤波，以在相对于第一系列移位的定时由a / m产生来自第二FIR子滤波器中的每一个的第二系列滤波数字采样 DELTA f，其中是从单位到（m-1）的整数，并且m是等于或大于2的整数。第一FIR子滤波器的输出与第二FIR子滤波器的输出组合，以产生频率的N个求和输出 米DELTA f。 N点快速傅立叶变换处理器（14）以频率m DELTA f对N个求和输出进行快速傅立叶变换，以得到数字通道。 由于在频率m DELTA f处的过采样，每个数字通道具有可以在带宽DELTA f上变得平坦的频率响应。

公开(公告)号：EP1154594A3

公开(公告)日：2004-08-18

申请号：EP01111583.9

申请日：2001-05-11

Applicant: NEC CORPORATION

Inventor： Ichiyoshi, Osamu

IPC: H04L5/02

CPC classification number: H04L5/026

Abstract: A spreading code setting circuit generates N vectors, as spreading codes, which are +1 or -1 polarity and are unique to users. A multiplier multiplies the nth data and the nth spreading code corresponding thereto for the spread modulation. An FDM combining circuit modulates N pieces of data according to the FDM method. A FDM separating circuit demodulates received signals according to the FDM method. An inverse spreading code setting circuit generates N vectors, as inverse spreading codes, which are +1 or -1 polarity and are unique to users at the transmission side. A multiplier multiplies the nth data and the nth inverse spreading code corresponding thereto for inverse spread modulation.

公开(公告)号：EP0817370B1

公开(公告)日：2001-11-21

申请号：EP97110849.3

申请日：1997-07-01

Applicant: NEC CORPORATION

Inventor： Ichiyoshi, Osamu

IPC: H03D7/16 ,  H04B1/40

CPC classification number: H03D7/163 ,  H04B1/405

公开(公告)号：EP1154594A2

公开(公告)日：2001-11-14

申请号：EP01111583.9

申请日：2001-05-11

Applicant: NEC CORPORATION

Inventor： Ichiyoshi, Osamu

IPC: H04L5/02

CPC classification number: H04L5/026

Abstract: A spreading code setting circuit generates N vectors, as spreading codes, which are +1 or -1 polarity and are unique to users. A multiplier multiplies the nth data and the nth spreading code corresponding thereto for the spread modulation. An FDM combining circuit modulates N pieces of data according to the FDM method. A FDM separating circuit demodulates received signals according to the FDM method. An inverse spreading code setting circuit generates N vectors, as inverse spreading codes, which are +1 or -1 polarity and are unique to users at the transmission side. A multiplier multiplies the nth data and the nth inverse spreading code corresponding thereto for inverse spread modulation.

Abstract translation: 扩展码设置电路产生N个向量，作为扩展码，它们是+1或-1极性，并且是用户唯一的。 乘法器将对应于其扩展调制的第n个数据和第n个扩展码相乘。 FDM组合电路根据FDM方法对N个数据进行调制。 FDM分离电路根据FDM方法解调接收信号。 反向扩展码设置电路产生作为反向扩展码的N个向量，其为+1或-1极性，并且对于发送侧的用户是唯一的。 乘法器将与其对应的第n个数据和第n个反向扩展码相乘以进行反向扩展调制。

公开(公告)号：EP0731556B1

公开(公告)日：2000-08-30

申请号：EP96301531.8

申请日：1996-03-06

Applicant: NEC Corporation

Inventor： Ichiyoshi, Osamu

IPC: H03F1/32 ,  H04L27/36

CPC classification number: H03C3/08 ,  H03F1/3247 ,  H03F1/3294 ,  H03F2200/102 ,  H03F2201/3233 ,  H04L27/368

公开(公告)号：EP0304890A2

公开(公告)日：1989-03-01

申请号：EP88113790.5

申请日：1988-08-24

Applicant: NEC CORPORATION

Inventor： Ichiyoshi, Osamu

IPC: H04B7/185

CPC classification number: H04B7/216

Abstract: For use in a satellite communication system which carries out communication through a satellite by the use of an up-link frequency band and a down-link frequency band, each of the up-link and the down-link frequency bands has a plurality of frequency subbands spaced apart from one another with frequency gaps interposed between the frequency subbands. An earth station comprises a modulating arrangement (47) for modulating a selected one of the frequency subbands of the up-link frequency band by a first input signal into a subband transmission signal, a first transmitting arrangement (51) coupled to the modulating arrangement for transmitting the subband transmission signal through the selected one of the frequency subbands, a spread spectrum processing arrangement (50) for processing a second input signal into a spread spectrum transmission signal in the up-link frequency band, and a second transmitting arrangement (51) coupled to the spread spectrum processing arrangement for transmitting the spread spectrum transmission signal through the up-link frequency band.

Abstract translation: 对于通过使用上行链路频带和下行链路频带通过卫星进行通信的卫星通信系统中，每个上行链路和下行链路频带具有多个频率 子频带彼此间隔开，频率间隔插入在频率子带之间。 地球站包括调制装置（47），用于通过第一输入信号将上行链路频带的选定一个频带调制成子带传输信号;耦合到调制装置的第一发射装置（51），用于 通过选择的一个频率子带发送子带传输信号;扩展频谱处理装置（50），用于将第二输入信号处理成上行链路频带中的扩展频谱传输信号;以及第二发射装置（51） 耦合到用于通过上行链路频带发射扩频发射信号的扩频处理装置。