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    Out of channel cyclic redundancy code method for a discrete multitone spread spectrum communications system
    5.
    发明授权
    Out of channel cyclic redundancy code method for a discrete multitone spread spectrum communications system 失效

    公开(公告)号：US06289037B1

    公开(公告)日：2001-09-11

    申请号：US08803831

    申请日：1997-02-24

    申请人： David Gibbons ,  Robert Lee Maxwell ,  David James Ryan

    发明人： David Gibbons ,  Robert Lee Maxwell ,  David James Ryan

    IPC分类号： H04L2730

    CPC分类号： H04L1/0003 ,  H04B1/69 ,  H04L1/0045 ,  H04L1/0057 ,  H04L1/16

    摘要： A new method makes the most efficient use of the scarce spectral bandwidth in a wireless discrete multitone spread spectrum communications system. Each remote station and each base station in the network prepares an error detection field, such as a cyclic code (CRC), on each block of data to be transmitted over the traffic channels. The sending station prepares an error detection message for transmission over the link control channel of the network. The sending station prepares the error detection message by forming a link control channel vector that will be spread using the discrete multitone spread spectrum (DMT-SS) protocol to distribute the data message over a plurality of discrete tone frequencies, forming a spread signal for the link control channel. A link control channel is associated with communications session using the traffic channels. The instant of transmission of the error detection message is allowed to be different from the instant of transmission of the data message. This permits the error detection messages to be transmitted when capacity is available on the link control channel. The receiving station buffers the error detection messages it receives from the link control channel, so that they are accessible by their block numbers. When the receiving station receives a data message on the traffic channel, it performs a CRC calculation on the data block in the message to obtain a resulting new CRC value. The new CRC value is also buffered at the receiving station with the block number so that it is accessible by its block number. Then, when both the received error message and the new CRC value are both available at the receiving station, they are matched by their common block number. The received CRC value in the error detection message is compared with the new CRC computed from the received data block. If the comparison determines that there is a difference in the values, then an error signal is generated.

    Out of channel cyclic redundancy code method for a discrete multitone spread spectrum communications system
    6.
    发明授权
    Out of channel cyclic redundancy code method for a discrete multitone spread spectrum communications system 失效

    公开(公告)号：US06639935B2

    公开(公告)日：2003-10-28

    申请号：US09902730

    申请日：2001-07-12

    申请人： David Gibbons ,  Robert Lee Maxwell ,  David James Ryan

    发明人： David Gibbons ,  Robert Lee Maxwell ,  David James Ryan

    IPC分类号： H04B169

    CPC分类号： H04L1/0003 ,  H04B1/69 ,  H04L1/0045 ,  H04L1/0057 ,  H04L1/16

    摘要： A new method makes the most efficient use of the scarce spectral bandwidth in a wireless discrete multitone spread spectrum communications system. Each remote station and each base station in the network prepares an error detection field, such as a cyclic redundancy code (CRC), on each block of data to be transmitted over the traffic channels. The sending station prepares an error detection message for transmission over the link control channel of the network. The sending station prepares the error detection message by forming a link control channel vector that will be spread using the discrete multitone spread spectrum (DMT-SS) protocol to distribute the data message over a plurality of discrete tone frequencies, forming a spread signal for the link control channel. A link control channel is associated with communications session using the traffic channels. The instant of transmission of the error detection message is allowed to be different from the instant of transmission of the data message. This permits the error detection messages to be transmitted when capacity is available on the link control channel. The receiving station buffers the error detection messages it receives from the link control channel, so that they are accessible by their block numbers. When the receiving station receives a data message on the traffic channel, it performs a CRC calculation on the data block in the message to obtain a resulting new CRC value. The new CRC value is also buffered at the receiving station with the block number so that it is accessible by its block number. Then, when both the received error message and the new CRC value are both available at the receiving station, they are matched by their common block number. The received CRC value in the error detection message is compared with the new CRC computed from the received data block. If the comparison determines that there is a difference in the values, then an error signal is generated.

    Access retry method for shared channel wireless communications links
    8.
    发明授权
    Access retry method for shared channel wireless communications links 失效
    共享信道无线通信链路的接入重试方法

    公开(公告)号：US06333937B1

    公开(公告)日：2001-12-25

    申请号：US09035287

    申请日：1998-03-05

    申请人： David James Ryan

    发明人： David James Ryan

    IPC分类号： H04J316

    CPC分类号： H04W72/044 ,  H04W24/00 ,  H04W74/00

    摘要： Each remote station in a wireless network cell that uses a collision oriented multiple access scheme, counts the number of retries attempted to gain access to the base station for a particular message. The accumulated value of the number of retries is then inserted in a retry count field of the access request message. After one or more retries, the base station successfully receives the access request message. The base station runs a common access channel allocation manager program that adaptively provides additional channels to the remote station, depending on the number of retries the remote station required to successfully transmit the access request message. In this manner, the base station has accurate information about the reduced performance that the remote stations suffer during an interval of high usage, to enable the base station to adaptively provide additional channels to the remote stations.

    摘要翻译： 在使用面向冲突的多址方案的无线网络小区中的每个远程站计数针对特定消息尝试获得对基站的访问的重试次数。 然后将重试次数的累积值插入到访问请求消息的重试计数字段中。 在一次或多次重试之后，基站成功接收到访问请求消息。 基站运行公共接入信道分配管理器程序，其根据远程站成功发送接入请求消息所需的重试次数，自动向远程站提供附加信道。 以这种方式，基站具有关于远程站在高使用间隔期间遭受的性能降低的准确信息，以使基站能够自适应地向远程站提供附加信道。

    Synchronization preamble method for OFDM waveforms in a communications system
    9.
    发明授权
    Synchronization preamble method for OFDM waveforms in a communications system 失效
    通信系统中OFDM波形的同步前导码方法

    公开(公告)号：US06643281B1

    公开(公告)日：2003-11-04

    申请号：US09035210

    申请日：1998-03-05

    申请人： David James Ryan

    发明人： David James Ryan

    IPC分类号： H04J306

    CPC分类号： H04W56/0065 ,  H04B7/2668 ,  H04L5/026

    摘要： A highly bandwidth-efficient communications method is disclosed that enables remote stations to synchronize in time and frequency to their serving base station. The invention enables a base station and its remote stations in a cell to synchronize in a noisy environment where signals interfere from other base stations and remote stations in other cells. The base station forms a forward synchronization burst that includes a plurality of tone frequencies arranged in a distinctive orthogonal frequency division multiplexed pattern unique to the base station. The unique pattern enables a remote station to distinguish the base station's bursts from other signals present in a crowded area. The distinctive orthogonal frequency division multiplexed pattern can be a Hadamard code pattern, for example. When the a base station has received a signal on a reverse link from a remote station, having significant interference, the base station selectively forms a request signal requesting the remote station to respond with a reverse synchronization burst that includes a plurality of tone frequencies arranged in the same distinctive orthogonal frequency division multiplexed pattern. The base station then transmits the forward synchronization burst and the request signal at a base station reference instant of time to the remote station. The reverse synchronization signals selectively occupy time slots in the transmission frame from the remote station to the base station, that would otherwise be occupied by channel control or traffic signals. Only when the base station requests the remote station to respond with a reverse synchronization burst, does this burst preempt the time slot from its other uses.

    摘要翻译： 公开了一种高带宽效率的通信方法，其使得远程站能够在时间和频率上与他们的服务基站同步。 本发明使得小区中的基站及其远程站在噪声环境中同步，其中信号干扰其他小区中的其他基站和远程站。 基站形成包括以基站特有的独特的正交频分复用模式排列的多个音调频率的前向同步突发。 独特的模式使得远程站能够将基站的突发与存在于拥挤区域中的其他信号区分开。 例如，独特的正交频分复用模式可以是Hadamard码模式。 当基站已经从远程站的反向链路上接收到信号时，具有明显的干扰，基站选择性地形成请求信号，请求远端站用反向同步脉冲串进行响应，该反向同步突发包括布置在 相同的独特正交频分复用模式。 然后，基站在基站参考时刻将远程同步脉冲串和请求信号发送到远程站。 反向同步信号选择性地占据从远程站到基站的传输帧中的时隙，否则这些时隙将被信道控制或业务信号所占据。 只有当基站请求远程站用反向同步突发进行响应时，这个突发是否会从其他用途中抢占时隙。

    FDD forward link beamforming method for a FDD communications system
    10.
    发明授权
    FDD forward link beamforming method for a FDD communications system 失效

    公开(公告)号：US6134261A

    公开(公告)日：2000-10-17

    申请号：US35286

    申请日：1998-03-05

    申请人： David James Ryan

    发明人： David James Ryan

    IPC分类号： H04B7/06 ,  H04B7/12 ,  H04K1/10

    CPC分类号： H04B7/12 ,  H04B7/0619 ,  H04B7/0617

    摘要： A highly bandwidth-efficient communications method is disclosed, to maximize the signal-to-interference-noise ratio (SINR) of transmissions from a base station to a remote station in a wireless communications system. The method is used for base stations that have a plurality of antenna elements that are capable of spatial beam steering by altering the relative phase of transmission of signals from the respective elements. The method of the invention is based on providing calibration frames that sequentially transmit calibration bursts from the respective antenna elements for a particular destination remote station. The calibration bursts include a plurality of tone frequencies arranged in a distinctive orthogonal frequency division multiplexed pattern unique to the base station. The unique pattern enables a remote station to distinguish the base station's bursts from other signals present in a crowded area. The distinctive orthogonal frequency division multiplexed pattern can be a Hadamard code pattern, for example. The plurality of calibration bursts are part of a transmission frame having a reference phase. The remote station receives the calibration bursts and measures values related to the relative phase difference between the calibration bursts and the reference phase. The remote station also measures the SINR of the received bursts. The measured values are then prepared as a sampling data message that is transmitted by the remote station back to the base station. The base station then calculates therefrom a beam steering correction to modify the relative phase difference. This beam steering correction is then applied to traffic bursts that are respectively transmitted from the plurality of antenna elements at the base station, to steer the plurality of traffic bursts toward the remote station. The beam steering correction steers the traffic bursts to maximize the signal-to-interference-noise ratio (SINR) of the traffic bursts at the remote station.