Soft handoff in OFDMA system
    11.
    发明授权
    Soft handoff in OFDMA system 有权
    OFDMA系统中的软切换

    公开(公告)号:US08165094B2

    公开(公告)日:2012-04-24

    申请号:US13221601

    申请日:2011-08-30

    IPC分类号: H04W36/00

    摘要: Soft handoff in an OFDMA system is disclosed. If the pilot signal strength for a base station exceeds the defined threshold, the base station is added to an active set list. Subcarriers in a plurality of orthogonal frequency division multiplexing (OFDM) symbols are divided and allocated into subchannels. The OFDM symbols are divided and multiplexed. A soft handoff zone with a first dimension of the subchannels and a second dimension of the divided and multiplexed OFDM symbols is defined. The soft handoff zone has subcarriers with a subchannel definition, for example, an identical permutation.

    摘要翻译: 披露了OFDMA系统中的软切换。 如果基站的导频信号强度超过定义的阈值,则将基站添加到活动集列表中。 多个正交频分复用(OFDM)符号中的子载波被划分并分配给子信道。 OFDM符号被分割和多路复用。 定义了具有子信道的第一维度和分割和多路复用的OFDM符号的第二维度的软切换区域。 软切换区具有子信道定义的子载波,例如相同的置换。

    Methods and systems for OFDM using code division multiplexing
    12.
    发明授权
    Methods and systems for OFDM using code division multiplexing 有权
    使用码分复用的OFDM方法和系统

    公开(公告)号:US08111763B2

    公开(公告)日:2012-02-07

    申请号:US11910091

    申请日:2006-03-30

    IPC分类号: H04L27/28

    摘要: In some embodiments of the invention, OFDM symbols are transmitted as a plurality of clusters. A cluster includes a plurality of OFDM sub-carriers in frequency, over a plurality of OFDM symbol durations in time. Each cluster includes data as well as pilot information as a reference signal for channel estimation. In some embodiments, a plurality of clusters collectively occupy the available sub-carrier set in the frequency domain that is used for transmission. In some embodiments of the invention data and/or pilots are spread within each cluster using code division multiplexing (CDM). In some embodiments pilots and data are separated by distributing data on a particular number of the plurality of OFDM symbol durations and pilots on a remainder of the OFDM symbol durations. CDM spreading can be performed in time and/or frequency directions.

    摘要翻译: 在本发明的一些实施例中,OFDM符号作为多个簇发送。 在多个OFDM符号持续时间内,群集包括频率上的多个OFDM子载波。 每个簇包括数据以及作为信道估计的参考信号的导频信息。 在一些实施例中,多个集群共同地占用用于传输的频域中的可用子载波集合。 在本发明的一些实施例中,使用码分多路复用(CDM)在每个簇内扩展数据和/或导频。 在一些实施例中,通过在OFDM码元持续时间的其余部分上分配关于多个OFDM符号持续时间的特定数目和导频上的数据来分离导频和数据。 可以在时间和/或频率方向上执行CDM扩展。

    Methods and Systems For Ofdm Multiple Zone Partitioning
    16.
    发明申请
    Methods and Systems For Ofdm Multiple Zone Partitioning 有权
    Ofdm多区域分区方法与系统

    公开(公告)号:US20080232504A1

    公开(公告)日:2008-09-25

    申请号:US12064563

    申请日:2006-08-23

    IPC分类号: H04B7/02

    摘要: Aspects of the invention include methods and devices for inserting data and pilot symbols into Orthogonal Frequency Division Multiplexing (OFDM) frames having a time domain and a frequency domain. A method involves inserting in at least one zone of a first type a two dimensional array of data and pilot symbols in time and frequency and inserting in at least one zone of a second type a two dimensional array of data and pilot symbols in time and frequency. In some implementations the zone of the first type comprises common pilot symbols that can be detected by all receivers receiving the OFDM frame. In some implementations the zone of the second type comprises dedicated pilot symbols that are only detectable by a receiver that is aware of pre-processing used to encode the dedicated pilot symbols. According to various embodiments of the invention, the zones of the first and second types can be partitioned in the OFDM frame based on time division multiplexing (TDM), frequency division multiplexing (FDM) or combined TDM/FDM. Examples of types of transmissions that could be transmitted in different zones of a single OFDM frame are OFDM multiple input multiple output (MIMO) transmissions and OFDM beam forming transmissions.

    摘要翻译: 本发明的方面包括用于将数据和导频符号插入具有时域和频域的正交频分复用(OFDM)帧的方法和装置。 一种方法包括在时间和频率上插入数据和导频符号的二维阵列的第一类型的至少一个区域,并在第二类型的至少一个区域中插入时间和频率的数据和导频符号的二维阵列 。 在一些实现中,第一类型的区域包括可由接收OFDM帧的所有接收机检测的公共导频符号。 在一些实施方式中,第二类型的区域包括专用导频符号,其仅可以被知道用于对专用导频符号进行编码的预处理的接收机检测。 根据本发明的各种实施例,可以基于时分复用(TDM),频分复用(FDM)或组合TDM / FDM,在OFDM帧中划分第一类和第二类的区。 可以在单个OFDM帧的不同区域中传输的传输类型的示例是OFDM多输入多输出(MIMO)传输和OFDM波束形成传输。

    Preambles in Ofdma System
    18.
    发明申请
    Preambles in Ofdma System 有权
    Ofdma系统中的前导码

    公开(公告)号:US20080039107A1

    公开(公告)日:2008-02-14

    申请号:US11630474

    申请日:2005-06-23

    IPC分类号: H04J11/00

    摘要: The present invention provides a preamble that is inserted into an OFDMA frame and has a common sequence for all the base stations participating in a transmission. The subscriber station performs fine synchronization using the common sequence on the common preamble, and the resulting peaks will provide the locations of candidate base stations. The base station specific search is then performed in the vicinities of those peaks by using base station specific pseudo-noise sequences. With this two stage cell search, the searching window is drastically reduced. The preamble is matched to known values by a respective receiver to decode the signals and permit multiple signals to be transferred from the transmitter to the receiver. The preamble may comprise two parts, Preamble-1 and Preamble-2, which may be used in different systems, including multioutput, multi-input (MIMO) systems.

    摘要翻译: 本发明提供插入到OFDMA帧中并具有参与传输的所有基站的公共序列的前同步码。 用户站使用公共前导码上的公共序列执行精细同步,并且所得到的峰值将提供候选基站的位置。 然后通过使用基站专用伪噪声序列,在那些峰附近执行基站专用搜索。 通过这两个阶段的单元格搜索,搜索窗口大大减少。 前导码由相应的接收机与已知值匹配以对信号进行解码,并允许多个信号从发射机传送到接收机。 前导码可以包括两个部分,即前导码1和前导码2,其可以在不同的系统中使用,包括多输入,多输入(MIMO)系统。