Device for changing the transmission parameters in a radio transmitter
    3.
    发明授权
    Device for changing the transmission parameters in a radio transmitter 失效
    用于改变无线电发射机中传输参数的装置

    公开(公告)号:US5768260A

    公开(公告)日:1998-06-16

    申请号:US607874

    申请日:1996-02-29

    IPC分类号: H04B17/00 H04W84/00 H04J3/14

    CPC分类号: H04W84/00 H04B17/18

    摘要: In a radio system of the digital simultaneous type comprising a number of radio transmitters, information is transmitted on the same nominal frequency. The system is also intended to transmit specific test information, with the intention of achieving optimal performance of measuring receivers. Receivers, either measuring receivers or conventional receivers, register their geographical location in the system and the reception conditions of different stations with the aid of the test information. The measuring result is returned to the transmitter stations, to decide which measures shall be taken. When this return of the measuring result from the reception area is automatic, changes in the transmission parameters will be effected automatically and continuously while taking prevailing traffic situations into account.

    摘要翻译: 在包括多个无线电发射机的数字同时类型的无线电系统中,以相同的标称频率发送信息。 该系统还旨在传送特定的测试信息,目的是实现测量接收机的最佳性能。 接收机,无论是测量接收机还是常规接收机,借助于测试信息在系统中注册其地理位置和不同台站的接收状况。 测量结果返回发射台,决定采取哪些措施。 当从接收区域返回测量结果是自动的时,考虑到主要的交通情况,传输参数的变化将自动连续地进行。

    Method for synchronization of transmitter and receiver at mobile radio
system
    6.
    发明授权
    Method for synchronization of transmitter and receiver at mobile radio system 失效
    移动无线电系统发射机和接收机同步的方法

    公开(公告)号:US6084871A

    公开(公告)日:2000-07-04

    申请号:US836985

    申请日:1997-08-20

    IPC分类号: H04B7/26 H04L7/08 H04L27/26

    CPC分类号: H04L27/2602

    摘要: A method of a mobile radio system for synchronization a transmitter and receiver. The system relates to MC/DS-CDMA-system. In the system information is transmitted digitally in frames. For that purpose a data channel, a pilot channel and a synchronization channel are created. In the data channel the data blocks D0, D1, D2 etc are separated by a guard space .DELTA.. In the pilot channel, respective the synchronization channel, the information is arranged in blocks which are synchronous with each other. The repeating distance, A, of the pilot channel, corresponds to the length of one of the data blocks D0, D1, D2 etc. The repeating distance for the synchronization channel is S, corresponding to a number of blocks in the data channel. In the synchronization channel information is introduced into the blocks which indicates their relation to the data channel. The method in this way allows an identification of the position of the pilot channel, which indicates the position of the synchronization channel, at which a decoding of the information of the the synchronization channel appoints the position of the data channel.

    摘要翻译: PCT No.PCT / SE95 / 01382 Sec。 371日期1997年8月20日 102(e)日期1997年8月20日PCT 1995年11月21日PCT PCT。 公开号WO96 / 17455 日期1996年6月6日一种用于同步发射机和接收机的移动无线电系统的方法。 该系统涉及MC / DS-CDMA系统。 在系统信息中以数字方式传送信息。 为此,创建数据信道,导频信道和同步信道。 在数据通道中,数据块D0,D1,D2等被保护空间DELTA隔开。 在导频信道中,对应于同步信道,信息被排列成彼此同步的块。 导频信道的重复距离A对应于数据块D0,D1,D2等中的一个的长度。同步信道的重复距离对应于数据信道中的块数。 在同步信道中,信息被引入指示它们与数据信道的关系的块中。 以这种方式,该方法允许识别指示同步信道的位置的导频信道的位置,在该位置处,同步信道的信息的解码指定数据信道的位置。

    Telecommunications transmission systems
    8.
    发明授权
    Telecommunications transmission systems 有权
    电信传输系统

    公开(公告)号:US07079610B1

    公开(公告)日:2006-07-18

    申请号:US09700617

    申请日:1999-05-11

    IPC分类号: H04B1/10

    摘要: In a multi-carrier system employing OFDM, for example DMT, an adaptive channel equalizer is normally used, operating in the frequency domain. The sampling clock is controlled so that the time delay between the transmitter and the receiver is effectively eliminated. If the information used to control the sampling clock is received from the equalized data stream, it will introduce an ambiguity between the operation of the channel equalizer and the mechanism used to control the sampling clock. Operation of the equalizer can mask an increasing time difference, between transmitter and receiver, which the sample clock controller should be tracking. The present invention eliminates the ambiguities in the operation of the equalizer and sample clock controller by preventing the equalizer from accepting time differences which should be corrected by operation of the sample clock controller.

    摘要翻译: 在采用OFDM的多载波系统中,例如DMT,通常使用自适应信道均衡器,在频域中工作。 控制采样时钟,以便有效地消除发射机和接收机之间的时间延迟。 如果从均衡数据流接收到用于控制采样时钟的信息,则会在通道均衡器的操作和用于控制采样时钟的机制之间引入歧义。 均衡器的操作可以掩盖采样时钟控制器应该跟踪的发射机和接收机之间的增加的时间差。 本发明通过防止均衡器接受应该通过采样时钟控制器的操作来校正的时间差来消除均衡器和采样时钟控制器的操作中的模糊性。

    Synchronisation
    9.
    发明授权
    Synchronisation 有权
    同步

    公开(公告)号:US06751261B1

    公开(公告)日:2004-06-15

    申请号:US09147230

    申请日:1999-02-09

    IPC分类号: H04L506

    摘要: With OFDM systems the frequency domain data is the Fourier transform of the received time domain OFDM frames. The time domain frames must be sampled, at the receiver, in synchronism with the transmitter, so that each received frame contains data from only a single transmitted frame. It is vital for this synchronism to be maintained in order to maintain the orthogonality of the frames. A typical multi-carrier system, of the OFDM type, which uses a cyclic prefix permits orthogonality to be maintained when there is a small deviation from exact frame synchronisation. Because the signalling interval includes both an entire frame and the cyclic prefix, which is a repetition of part of the frame, a frame sampled within the signalling interval will contain data from only one frame. Since the signalling interval is greater than the frame period, this gives some leeway in frame alignment. In a multi-carrier system of the OFDM type, an adaptive channel equalizer, operating in the frequency domain, is often used. The internal parameters in such an equalizer contain, in addition to information about the characteristics of the channel, information which can be interpreted as the time deviation between the sampling clocks of the transmitter and the receiver. The present invention utilizes this information to control the sampling clock of the receiver in a more robust way than has previously been possible with known techniques. The present invention is particularly suitable for use in ADSL and VDSL modems which can be used to give broadband access over copper networks. The invention is also of relevance to broadband transmission in mobile and semi-mobile systems for transmission over the radio channels.

    摘要翻译: 对于OFDM系统,频域数据是接收的时域OFDM帧的傅里叶变换。 必须在接收机处与发射机同步地采样时域帧,使得每个接收的帧包含来自仅一个发射帧的数据。 为了保持帧的正交性,保持该同步是至关重要的。 使用循环前缀的OFDM类型的典型多载波系统当与精确帧同步的偏差很小时,允许维持正交性。 由于信令间隔包括作为帧的一部分的重复的整个帧和循环前缀,所以在信令间隔内采样的帧将仅包含来自一个帧的数据。 由于信令间隔大于帧周期,所以在帧对齐中给出了一些余地。 在OFDM类型的多载波系统中,经常使用在频域中工作的自适应信道均衡器。 除了关于信道特性的信息之外,这种均衡器中的内部参数还包含可被解释为发射机和接收机的采样时钟之间的时间偏差的信息。 本发明利用该信息以比先前已知技术可能的更可靠的方式来控制接收机的采样时钟。 本发明特别适用于ADSL和VDSL调制解调器,可用于通过铜网络提供宽带接入。 本发明还涉及用于在无线电信道上传输的移动和半移动系统中的宽带传输。