公开(公告)号：US5581580A

公开(公告)日：1996-12-03

申请号：US063977

申请日：1993-05-20

申请人： Lars Lindbom ,  Karim Jamal

发明人： Lars Lindbom ,  Karim Jamal

IPC分类号： H04B7/08 ,  H04L1/20 ,  H04L25/02 ,  H03D1/00 ,  H04L27/06

CPC分类号： H04L25/0242 ,  H04L1/20 ,  H04L25/0212 ,  H04L25/0236 ,  H04L25/025 ,  H04B7/0845

摘要： A low complexity model based channel estimator is disclosed for use by a receiver in Rayleigh fading environments. The receiver contains at least one channel state estimator which uses an auto regressive model for channel variations. The channel state estimates are initialized by using at least preliminarily detected symbols. The receiver also contains a data detector which uses the received signal and the channel estimate, or a function thereof, delivered by at least one channel estimator to detect the transmitted symbols.

摘要翻译： 公开了一种基于低复杂度模型的信道估计器，用于由瑞利衰落环境中的接收机使用。 接收机包含至少一个信道状态估计器，其使用用于信道变化的自回归模型。 通过使用至少预先检测的符号来初始化信道状态估计。 该接收机还包含一个数据检测器，它使用由至少一个信道估计器传送的接收信号和信道估计或其功能来检测所发送的符号。

公开(公告)号：US06760361B2

公开(公告)日：2004-07-06

申请号：US09742714

申请日：2000-12-20

申请人： Per Johan Anders Nyström ,  Karim Jamal ,  Riaz Esmailzadeh ,  Yi-Pin Eric Wang

发明人： Per Johan Anders Nyström ,  Karim Jamal ,  Riaz Esmailzadeh ,  Yi-Pin Eric Wang

IPC分类号： H04L2732

CPC分类号： H04B1/7083 ,  H04J13/107 ,  H04L7/043

摘要： A special coding scheme is disclosed for more effectively acquiring a long code and frame timing during a cell search in a CDMA communications system. A code set of length M Q-ary code words including symbols from a set of Q short codes is defined with certain properties. The primary property to be satisfied is that no cyclic shift of a code word yields a valid code word. The other properties to be satisfied are that there is a one-to-one mapping between a long code message and a valid code word, and a decoder should be able to find both the random shift (thereby implicitly finding the frame timing) and the transmitted code word (i.e., its associated long code indication message) in the presence of interference and noise, with some degree of accuracy and reasonable complexity.

摘要翻译： 公开了一种特殊的编码方案，用于在CDMA通信系统中的小区搜索期间更有效地获取长码和帧定时。 使用某些属性来定义包括来自一组Q短码的符号的长度为M个Q字节码字的码组。 要满足的主要特征是代码字的循环移位不产生有效的代码字。 要满足的其他属性是在长码消息和有效码字之间存在一对一的映射，并且解码器应该能够找到随机移位（从而隐含地找到帧定时）和 在存在干扰和噪声的情况下，传输码字（即其相关联的长码指示消息）具有一定程度的准确性和合理的复杂度。

公开(公告)号：US06597675B1

公开(公告)日：2003-07-22

申请号：US09148224

申请日：1998-09-04

申请人： Riaz Esmailzadeh ,  Karim Jamal ,  Christiaan Roobol

发明人： Riaz Esmailzadeh ,  Karim Jamal ,  Christiaan Roobol

IPC分类号： H04B7216

CPC分类号： H04L1/1867 ,  H04B1/707 ,  H04B2201/70701 ,  H04J13/107 ,  H04W28/06 ,  H04W72/0466 ,  H04W74/004 ,  H04W74/0833

摘要： A method is disclosed for processing mobile-originated random access requests in a mobile telecommunications system that randomly selects new signatures for re-transmissions in the event that collisions have occurred. As such, the random access re-transmissions are randomized over the signature domain instead of just over the time domain. Consequently, the disclosed invention significantly shortens random access delays caused by collisions or erroneous arrivals at base station receivers, and also significantly reduces the interval between random access re-transmissions.

摘要翻译： 公开了一种用于在移动电信系统中处理移动发起的随机接入请求的方法，该方法在发生冲突的情况下随机选择用于重传的新签名。 因此，随机访问重传是通过签名域而不是仅在时域上随机化的。 因此，所公开的发明显着缩短了由基站接收机的冲突或错误到达引起的随机接入延迟，并且还显着地减少了随机接入重传之间的间隔。

公开(公告)号：US06526039B1

公开(公告)日：2003-02-25

申请号：US09243095

申请日：1999-02-02

申请人： Erik Bengt Lennart Dahlman ,  Karim Jamal ,  Johan Anders Nyström ,  Mats Cedervall ,  Patrik Lundqvist

发明人： Erik Bengt Lennart Dahlman ,  Karim Jamal ,  Johan Anders Nyström ,  Mats Cedervall ,  Patrik Lundqvist

IPC分类号： H04B7216

CPC分类号： H04B1/7083 ,  H04W56/002 ,  H04W92/10

摘要： A method and system are disclosed for facilitating the timing (e.g., the known relative timing differences) of base stations (BSs) in asynchronous CDMA mobile communications systems. A plurality of mobile stations (MSs) measure the relative time differences between various pairs of BSs, and these measurements are stored by the BSs. A source BS sends to an MS, in a neighbor list message, estimates of the relative time difference between the source BS and each of the BSs on the neighboring cell list. Each BS on the list can maintain a relative time difference estimate table, which can be updated continuously from the reports received from MSs. Subsequently, the BSs can send entries from this table to the MS in the neighbor list message. Using this novel technique, the BSs have known relative timing differences. Consequently, when the MS initiates a cell-search for a candidate BS, the MS already has an estimate of the timing of that BS as compared to its source BS. As such, the resulting cell-search procedure has a lower level of complexity and thus can be accomplished much quicker than with prior procedures. In addition, the relative time difference estimates can be compared with corresponding time differences that are measured by a second mobile station. Based on this comparison, the propagation delays of signals between the second MS and various BSs can be calculated to determine the position of the second MS.

摘要翻译： 公开了用于促进异步CDMA移动通信系统中的基站（BS）的定时（例如，已知的相对定时差）的方法和系统。 多个移动站（MS）测量各对BS之间的相对时间差，并且这些测量由BS存储。 源BS在邻居列表消息中向MS发送源BS与相邻小区列表上的每个BS之间的相对时间差的估计。 列表中的每个BS可以保持相对时间差估计表，其可以从从MS接收到的报告中连续地更新。 随后，BS可以在邻居列表消息中从该表发送条目到MS。 使用这种新技术，BS已知相对时间差。 因此，当MS发起对候选BS的小区搜索时，MS已经具有与其源BS相比该BS的定时的估计。 因此，所得到的细胞搜索程序具有较低的复杂度，因此可以比先前的程序更快地完成。 此外，相对时间差估计可以与由第二移动台测量的对应时间差进行比较。 基于该比较，可以计算第二MS与各个BS之间的信号的传播延迟，以确定第二MS的位置。

公开(公告)号：US06442153B1

公开(公告)日：2002-08-27

申请号：US09169731

申请日：1998-10-09

申请人： Erik Dahlman ,  Karim Jamal

发明人： Erik Dahlman ,  Karim Jamal

IPC分类号： H04B7216

CPC分类号： H04W74/0833 ,  H04B7/2637 ,  H04W28/06

摘要： A novel format is provided for an uplink common physical channel in a random access mobile communications system, whereby a mobile station transmits a first packet including a predetermined signature pattern in parallel with a second packet including the data part of the random access request. Consequently, in addition to its attendant advantages, the signature part of a random access request can also function as a Pilot by providing additional energy for channel estimation during the data part of the request, while reducing the amount of overhead signalling involved. This additional energy is especially useful for ensuring sufficiently high quality coherent detection of the data part in a rapidly varying radio channel environment.

摘要翻译： 为随机接入移动通信系统中的上行链路公共物理信道提供一种新颖的格式，由此移动台与包括随机接入请求的数据部分的第二分组并行发送包括预定签名模式的第一分组。 因此，除了其伴随的优点之外，随机接入请求的签名部分还可以通过在请求的数据部分期间为信道估计提供额外的能量，同时减少所涉及的开销信令的量，来用作导频。 这种额外的能量对于确保在快速变化的无线电信道环境中的数据部分的足够高的质量相干检测特别有用。

公开(公告)号：US5930366A

公开(公告)日：1999-07-27

申请号：US921135

申请日：1997-08-29

申请人： Karim Jamal ,  Riaz Esmailzadeh ,  Yi-Pin Eric Wang

发明人： Karim Jamal ,  Riaz Esmailzadeh ,  Yi-Pin Eric Wang

IPC分类号： H04B1/7073 ,  H04B1/7075 ,  H04B1/7083 ,  H04B7/26 ,  H04Q7/38 ,  H04L9/00

CPC分类号： H04B1/70752 ,  H04B1/70735 ,  H04B1/7083 ,  H04B2201/70701

摘要： Each transmission frame within a spread spectrum communications system relating to synchronization code transmission is divided into a plurality of slots. Each of the slots includes a primary (pilot) code c.sub.p and a secondary (combined) code c.sub.s/lci that includes information identifying or indicative of both a frame timing and a scrambling code for synchronization. This information concerning frame timing and scrambling code may be encoded in the combined code c.sub.s/lci itself, as well as in the modulation values of the sequences of plural combined codes within a frame. Alternatively, the information is encoded in the sequence of plural combined codes c.sub.s/lci transmitted in each frame, as well as in the modulated values of the sequences of plural combined codes within a frame. As yet another alternative, the information is encoded in the timing of the combined code c.sub.s/lci transmission within each slot of the frame relative to its associated primary code c.sub.p.

摘要翻译： 与同步码传输相关的扩频通信系统内的每个传输帧被划分成多个时隙。 每个时隙包括主（代码）代码+ E，ovs c + EE p和辅助（组合）代码+ E，ovs c + EE s / lci，其包括识别或指示帧定时和加扰 同步代码 关于帧定时和扰码的信息可以以组合码+ E，ovs c + EE s / lci本身以及帧内的多个组合码的序列的调制值进行编码。 或者，信息按照在每帧中发送的多个组合码+ E，ovs + EE s / lci的序列以及帧内的多个组合码的序列的调制值进行编码。 作为另一个替代方案，信息在帧相对于其相关联的主代码+ E，ovs c + EE p的每个时隙内的组合代码+ E，ovs c + EE s / lci传输的定时编码。

公开(公告)号：US5757821A

公开(公告)日：1998-05-26

申请号：US684792

申请日：1996-07-22

申请人： Karim Jamal ,  Johan Nystrom

发明人： Karim Jamal ,  Johan Nystrom

IPC分类号： H03M13/00 ,  H03M13/35 ,  H03M13/41 ,  H03M13/45 ,  H04L27/00 ,  H04L27/22

CPC分类号： H03M13/2703 ,  H03M13/00 ,  H03M13/35 ,  H03M13/4146

摘要： A method and system for transmitting signals using unequal error protection (UEP). According to the method, symbols having a higher level of coding protection are detected and decoded first, soft reliability information is generated, and then the previously detected symbols and soft reliability information are used to detect and decode symbols having the next lower level of coding protection. The symbols having lower levels of coding protection benefit from the decoding of all previous classes of symbols. Data symbols can be interleaved to further enhance system performance.

摘要翻译： 一种使用不等错误保护（UEP）传输信号的方法和系统。 根据该方法，首先检测和解码具有较高编码保护级别的符号，生成软可靠性信息，然后使用先前检测到的符号和软可靠性信息来检测和解码具有下一较低编码保护级别的符号 。 具有较低编码保护水平的符号受益于所有先前类别的符号的解码。 数据符号可以交错以进一步提高系统性能。

公开(公告)号：US5727032A

公开(公告)日：1998-03-10

申请号：US540098

申请日：1995-10-06

申请人： Karim Jamal ,  Bjorn Gudmundson ,  Gustav Brismark

发明人： Karim Jamal ,  Bjorn Gudmundson ,  Gustav Brismark

IPC分类号： H03H21/00 ,  H04L7/04 ,  H04L25/02 ,  H04L25/03 ,  H04B7/10 ,  H04L1/02

CPC分类号： H03H21/0012 ,  H04L25/03261 ,  H04L25/0212 ,  H04L7/042

摘要： In a digital signal transmission system, a receiver receives a signal, wherein the signal bandwidth of the system exceeds the system symbol rate. A correlation and sampling circuit receives a baseband signal, samples the signal eight times per symbol time, correlates, generates a channel estimate and down-samples the sampled signal to form an observed signal. This signal is filtered in a prefilter, whose output is sampled at symbol rate and the obtained signal is delivered to a channel equalizer which performs a viterbi algorithm with non-quadratic metric calculation and generates estimated symbols. A channel estimation filter receives a symbol sequence which contains alternate zero-value symbols and the estimated symbols and generates an estimated signal. An error signal is generated and used to adapt the channel estimate and also to generate weight factors. The coefficients of the prefilter are generated as a function of the channel estimate and the weight factors. Coefficients are generated in a metric calculation filter, by convolving the channel estimate with the prefilter and are used to generate the estimated symbols. The transmission channel, excluding the prefilter, is estimated explicitly so as to enable fast channel changes to be followed. The use of the weight factors enables a short channel estimate to be used. The insertion of the zero-value symbols simplifies adaptation of the channel estimate.

公开(公告)号：US5299235A

公开(公告)日：1994-03-29

申请号：US757296

申请日：1991-09-10

申请人： Gustav Larsson ,  Karim Jamal

发明人： Gustav Larsson ,  Karim Jamal

IPC分类号： H04B7/26 ,  H04L7/027 ,  H04L7/033 ,  H04L7/04 ,  H04L7/08 ,  H04L7/00

CPC分类号： H04L7/0334 ,  H04L7/04

摘要： A method for improving time synchronization of digital data signals in receivers by using more than one known data sequence to provide a plurality of timing recovery functions and based on these, one or more optimal sampling points. By using existing data sequences in each frame, the disclosed method provides improved time synchronization without increasing transmission overhead.

摘要翻译： 一种用于通过使用多于一个已知数据序列来提高接收机中的数字数据信号的时间同步的方法，以提供多个定时恢复功能，并且基于这些，一个或多个最佳采样点。 通过使用每个帧中的现有数据序列，所公开的方法提供改进的时间同步而不增加传输开销。