公开(公告)号：US5533067A

公开(公告)日：1996-07-02

申请号：US264491

申请日：1994-06-23

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 ,  H04L27/06 ,  H03H7/30

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.

摘要翻译： 在数字信号传输系统中，接收机接收信号，其中系统的信号带宽超过系统符号速率。 相关和采样电路接收基带信号，每个符号时间八次采样信号，相关，产生信道估计并对采样信号进行下采样以形成观测信号。 该信号在预滤波器中被滤波，其输出以符号速率被采样，并且将获得的信号传送到信道均衡器，该信道均衡器执行具有非二次度量计算的维特比算法并生成估计符号。 信道估计滤波器接收包含交替的零值符号和估计符号的符号序列，并产生估计信号。 产生误差信号并用于适应信道估计，并产生权重因子。 作为信道估计和权重因子的函数产生预滤波器的系数。 在度量计算滤波器中生成系数，通过将信道估计与预滤波器进行卷积，并用于生成估计的符号。 不包括预过滤器的传输通道被明确估计，以便能够跟随快速通道改变。 使用权重因子可以使用短信道估计。 零值符号的插入简化了信道估计的适应。

公开(公告)号：US5901186A

公开(公告)日：1999-05-04

申请号：US737765

申请日：1996-10-28

申请人： Karim Jamal ,  Fredrik Jansson

发明人： Karim Jamal ,  Fredrik Jansson

IPC分类号： H04B14/04 ,  H04L1/00 ,  H04L1/20 ,  H04L25/03 ,  H03D1/04 ,  H03K5/01 ,  H03K6/04 ,  H04B1/10

CPC分类号： H04L1/20 ,  H04L1/0057 ,  H04L1/0071 ,  H04L1/201 ,  H04L25/03178

摘要： In a digital radio communication system in which information is transmitted and received in time slots and some bits of each received audio frame is interleaved over at least two time slots and other bits in each audio frame at are non-interleaved, bad received audio frames are detected by detecting possible bit errors in a channel encoded non-interleaved bit sequence in each received time slot. If bit errors have been detected in this bit sequence a bad received frame is indicated.

摘要翻译： PCT No.PCT / SE95 / 00423 Sec。 371日期1996年10月28日第 102（e）日期1996年10月28日PCT 1995年4月19日PCT PCT。 WO95 / 30282 PCT公开 日期：1995年11月9日在数字无线电通信系统中，其中在时隙中发送和接收信息，并且每个接收的音频帧的某些比特在至少两个时隙上进行交织，并且每个音频帧中的其他比特是非交织的， 通过检测每个接收到的时隙中的信道编码的非交错比特序列中的可能比特错误来检测不良的接收音频帧。 如果在该位序列中检测到位错误，则指示错误的接收帧。

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：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：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：US5596607A

公开(公告)日：1997-01-21

申请号：US079886

申请日：1993-06-23

申请人： Lars G. Larsson ,  Perols B. O. Gudmundson ,  Karim Jamal

发明人： Lars G. Larsson ,  Perols B. O. Gudmundson ,  Karim Jamal

IPC分类号： H04B1/10 ,  H04B7/005 ,  H04L25/02 ,  H04L25/03 ,  H04L27/06 ,  H03D1/00

CPC分类号： H04L25/03178 ,  H04B7/005 ,  H04L25/025 ,  H04L25/03292 ,  H04L25/03324

摘要： In a digital time-shared transmission system, a receiver receives a signal whose symbol rate is lower than the channel bandwidth of the system. A correlating and sampling circuit receives a baseband signal, samples the signal a number of times with each symbol time, performs channel correlation, generates a channel estimate and samples down the once sampled signal to an observed signal with two values for each symbol time. A channel equalizer executes a fractional viterbi algorithm which utilizes two delta-metric values for each state transition and generates estimated symbols. A channel estimating filter receives a symbol sequence of alternating zero-value symbols and the estimated symbols and generates an estimated signal. The channel estimating filter is adapted with the aid of an error signal and the filter delivers a channel estimate to the channel equalizer. Weighting factors are generated with the aid of the error signal and the two aforementioned delta-metric values are co-weighted to a common delta-metric value with the aid of weighting factors, this common delta-metric value being used to generate the estimated symbols. The use of the weighting factors improves the metric calculation and enables the channel estimating filter and the channel equalizer to be relatively simple. The insertion of the zero-value symbols simplifies the generation of the weighting factors and the adaptation of the channel estimating filter.

摘要翻译： 在数字时分传输系统中，接收机接收符号率低于系统信道带宽的信号。 相关和采样电路接收基带信号，每个符号时间多次采样信号，执行信道相关，产生信道估计，并将一次采样信号采样到具有每个符号时间的两个值的观测信号。 信道均衡器执行分数维特比算法，其利用每个状态转换的两个Δ度量值并产生估计符号。 信道估计滤波器接收交替的零值符号和估计符号的符号序列，并产生估计信号。 信道估计滤波器借助于误差信号进行调整，并且滤波器向信道均衡器传送信道估计。 借助于误差信号产生加权因子，并且借助于加权因子将两个前述的delta度量值共同加权到公共的delta度量值，该公共的delta度量值用于生成估计符号 。 使用加权因子改善了度量计算，使信道估计滤波器和信道均衡器相对简单。 零值符号的插入简化了加权因子的生成和信道估计滤波器的适应。

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。