专利快速检索-快速检索全球专利，免费商用专利数据库-IPRDB

1. 发明公开

EP1135909A1 SYSTEMS AND METHODS FOR RECEIVING A MODULATED SIGNAL CONTAINING ENCODED AND UNENCODED BITS USING MULTI-PASS DEMODULATION 有权
标题翻译：系统和方法，用于接收已调制信号编码，并且不KORDIERTE BITS含MEHRDURCHGANGSDEMODULATION
公开(公告)号：EP1135909A1
公开(公告)日：2001-09-26
申请号：EP99973201.9
申请日：1999-10-15
申请人： Ericsson, Inc.
发明人： BALACHANDRAN, Kumar , KHAYRALLAH, Ali
IPC分类号： H04L25/03
CPC分类号： H04L25/03171 , H04L1/005 , H04L1/007 , H04L25/03216 , H04L25/03273
摘要： Methods and systems are provided for receiving a modulated signal including symbols representing both encoded and unencoded bits from a data (e.g., speech) frame where a received slot is first demodulated and the encoded bits are decoded. The decoded bits are then utilized to constrain demodulation during a second demodulation of a received slot. The encoded bit positions from the constrained second demodulation are, in turn, encoded to generate bit estimates for the received slot. This information is combined with the output of the constrained second demodulation for unencoded bits to provide a received data frame estimate which has been shown to have improved reliability for both encoded and unencoded bits. The methods and systems further provide for recursively repeating the demodulation and decoding steps until a counter expires or a desired reliability is obtained.

2. 发明授权

EP0520969B1 Maximum likelihood sequence estimation for a mobile digital cellular radio receiver 失效
标题翻译：对于移动蜂窝无线接收器的最大似然序列估计
公开(公告)号：EP0520969B1
公开(公告)日：1998-04-29
申请号：EP92850154.3
申请日：1992-06-23
申请人： Hughes Aircraft Company
发明人： Parr, Michael I. , Watson, John L. , Vishwanath, T. G.
IPC分类号： H04L25/30 , H04L27/22
CPC分类号： H04L25/03248 , H04L25/025 , H04L25/03273 , H04L25/03292 , H04L2027/0065

3. 发明公开

EP0684708A4 ADAPTIVE EQUALIZER. 失效
标题翻译：自适应均衡器。
公开(公告)号：EP0684708A4
公开(公告)日：1997-06-04
申请号：EP95902947
申请日：1994-12-14
申请人： NIPPON TELEGRAPH & TELEPHONE
发明人： FUKAWA KAZUHIKO A GOUSHITSU , YOSHINO HITOSHI , SUZUKI HIROSHI
IPC分类号： H04B7/005 , H04L25/03 , H04L27/01 , H04B1/76
CPC分类号： H04L25/03273
摘要： Base-band signals obtained by asynchronously detecting received signals are sampled and the signals, are written in a buffer memory (11) as series of base-band signals samples. A most likelihood sequence estimating section (15) generates a desirerd symbol sequence corresponding to the samples read out from the memory (11) and supplies the symbol sequence to a transversal filter (18) having characteristics estimated from the impulse response of the transmission line at the timings of the samples. A phase error detecting section (23) successively detects the phase errors between estimated received signals obtained and corresponding base-band signal samples. An offset correcting signal generating section (22) calculates an estimated offset angular frequency DELTA omega e from the phase errors, generates an offset correcting signal having an angular frequency in the reverse direction of rotation, whose absolute value is equal to that of the estimated offset angular frequency DELTA omega e, and supplies the offset correcting signal to a multiplier (21) for correction. The multiplier (21) corrects the offset angular frequency so as to cancel the angular frequency offset by multiplying the samples by the offset correcting signal. A subtractor (14) finds the difference between the corrected samples and estimated signals received from the transversal filter as estimated errors. The estimating section (15) finds the most likelihood information from the estimated errors and discriminates signals by using a most likelihood sequence estimating algorithm based on the most likelihood information.

4. 发明公开

EP0520969A3 Maximum likelihood sequence estimation for a mobile digital cellular radio receiver 失效
标题翻译：移动数字蜂窝无线电接收机的最大比特率序列估计
公开(公告)号：EP0520969A3
公开(公告)日：1993-10-13
申请号：EP92850154.3
申请日：1992-06-23
申请人： Hughes Aircraft Company
发明人： Parr, Michael I. , Watson, John L. , Vishwanath, T. G.
IPC分类号： H04L25/30 , H04L27/22
CPC分类号： H04L25/03248 , H04L25/025 , H04L25/03273 , H04L25/03292 , H04L2027/0065
摘要： The present invention provides for an equalization method that forms the nucleus of a receiver for digital cellular mobile telephones. A number of distinct aspects of the design are considered novel, including non-real time operation that permits and exploits "time-reversed" equalization to significantly enhance bit error rate performance. The present invention employs the use of a maximum likelihood sequence estimation process. It uses variable coefficient least mean square tracking during estimation of the transmission channel's impulse response. It also employs the use of integrated symbol timing adjustment and carrier tracking algorithms. Time-reversed operation further enhances performance and permits implementation with reasonable complexity of a standards compliant mobile receiver.

5. 发明授权

EP3021542B1 ITERATIVE POST-EQUALIZATION FOR COHERENT OPTICAL RECEIVERS 有权
公开(公告)号：EP3021542B1
公开(公告)日：2018-09-26
申请号：EP15275235.8
申请日：2015-11-13
申请人： ZTE Corporation
发明人： Jia, Zhensheng , Cai, Yi
IPC分类号： H04L25/03
CPC分类号： H04B10/6165 , H04L1/0047 , H04L1/0054 , H04L7/048 , H04L25/03019 , H04L25/03267 , H04L25/03273 , H04L2025/03636
摘要： A post-equalization technique for recovering data bits from a coherent modulation optical signal is implemented in the digital domain by iteratively performing a decision-directed least mean square channel equalization step, a digital post filter step and a maximum likelihood sequence estimation step so that the symbol decisions of the previous iteration are fed to the decision directed least mean square channel equalization step to successively improve the symbol decisions. In an experimental setup, the iterative technique demonstrated performance improvement mitigating the bandwidth limitation as compared to a corresponding non-iterative technique.

6. 发明公开

EP0959568A4 RECEIVER WITH FREQUENCY OFFSET CORRECTING FUNCTION 失效
标题翻译： EMPFÄNGERMIT FREQUENZVERSATZKORREKTIONSFUNKTION
公开(公告)号：EP0959568A4
公开(公告)日：2007-09-26
申请号：EP97905438
申请日：1997-03-04
申请人： MITSUBISHI ELECTRIC CORP
发明人： NAGAYASU TAKAYUKI , MURAKAMI KEISHI
IPC分类号： H04L25/02 , H03J7/02 , H04B7/01 , H04L25/03 , H04L27/00
CPC分类号： H04L25/0236 , H03J7/02 , H04B7/01 , H04L25/0212 , H04L25/0226 , H04L25/025 , H04L25/03273 , H04L25/03292 , H04L27/0014 , H04L2027/0038 , H04L2027/0055 , H04L2027/0059 , H04L2027/0067
摘要： A receiver with frequency offset correcting function corrects distortion caused by interference between codes and a frequency offset in received signals. In order to correct the distorsion, a frequency offset correcting circuit (21) corrects the received signals based on an estimated frequency offset value. A first CIR estimating circuit (22) finds an estimated CIR value at a first position based on an already known training sequence in the corrected received signals. A second estimating circuit (24) finds another estimated CIR value at a second position which is different from the first position by updating the estimated CIR value at the first position as an initial value in accordance with an LMS algorithm based on the corrected received signals and a decision value outputted from an equalizer (13). A phase deviation detecting circuit (15) calculates phase deviations based on the estimated CIR values at the first and second positions and an averaging circuit (26) averages the phase deviations and outputs the average phase deviation to a frequency offset correcting circuit (21) as an estimated frequency offset value.
摘要翻译：具有频率偏移校正功能的接收器校正由码间干扰和接收信号中的频率偏移引起的失真。为了校正失真，频率偏移校正电路（21）基于估计的频率偏移值校正接收到的信号。第一CIR估计电路（22）基于校正的接收信号中的已知训练序列在第一位置处找到估计的CIR值。第二估计电路（24）根据基于校正后的接收信号的LMS算法，通过更新第一位置处的估计CIR值作为初始值，在不同于第一位置的第二位置处找到另一估计CIR值，以及从均衡器（13）输出的判定值。相位偏差检测电路（15）根据第一位置和第二位置处的估计CIR值计算相位偏差，平均电路（26）对相位偏差进行平均，并将平均相位偏差输出到频率偏移校正电路（21），作为估计的频率偏移值。

7. 发明授权

EP0724346B1 Procédé de calcul du déphasage dans un système de réception de signaux de données 失效
标题翻译：一种用于确定在数字数据接收器中的相位误差的方法
公开(公告)号：EP0724346B1
公开(公告)日：2003-05-28
申请号：EP96400157.2
申请日：1996-01-23
申请人： Thales
发明人： Soubaras, Hélène
IPC分类号： H04L25/03 , H04L7/033
CPC分类号： H04L7/0334 , H04L25/03184 , H04L25/03273

8. 发明授权

EP0504890B1 Demodulator for demodulating a pi/4-shift DQPSK signal 失效
标题翻译：解调器，用于解调一个π/ 4移键控DQPSK信号
公开(公告)号：EP0504890B1
公开(公告)日：2002-06-19
申请号：EP92104799.9
申请日：1992-03-19
申请人： SONY CORPORATION
发明人： Sato, Teruo
IPC分类号： H04L27/22
CPC分类号： H04L27/2276 , H04L25/03273 , H04L27/2275

9. 发明公开

EP0813768A1 SLOPE, DRIFT AND OFFSET COMPENSATION IN ZERO-IF RECEIVERS 失效
标题翻译：变化速度和漂移偏移补偿零中频接收器
公开(公告)号：EP0813768A1
公开(公告)日：1997-12-29
申请号：EP96911247
申请日：1996-03-01
申请人： ERICSSON GE MOBILE INC
发明人： LINDQUIST BJOERN , DENT PAUL W
IPC分类号： H03M3/02 , H03D3/00 , H03D7/16 , H03M13/39 , H04B1/26 , H04B1/30 , H04L25/03 , H04L27/14 , H04L27/22 , H04L27/233
CPC分类号： H03D7/165 , H03D3/008 , H04L25/03273 , H04L27/233 , H04L2025/03401 , H04L2025/03407
摘要： A method for processing a signal modulated with information symbols to account for an additive offset and slope is disclosed. First, an inital estimate of offset and slope is made and hypotheses of all possible values of a sequence of one or more information symbols are then made. For each of said hypotheses, the associated data symbol sequence is used to make an improved estimate of offset and slope and the improved estimate of offset and slope are stored against each of the hypotheses. For each hypothesis, the improved estimate of offset and slope is used in calculating an expected signal value and a mismatch between a sample of the modulated signal and the expected value is computed. The hypotheses are then sequentially extended by one symbol, the slope and offset estimates are updated and the mismatches are accumulated to form a path metric value for each extended hypothesis, and resolving between said hypotheses based on said path metric values using a Viterbi Sequential Maximum Likelihood Sequence Estimation process to produce a most likely hypothesis of said modulated information symbols substantially unimpaired by said additive slope and offset.

10. 发明公开

EP0684708A1 ADAPTIVE EQUALIZER 失效
标题翻译： ADAPTIVER ENTZERRER。
公开(公告)号：EP0684708A1
公开(公告)日：1995-11-29
申请号：EP95902947.1
申请日：1994-12-14
申请人： NTT MOBILE COMMUNICATIONS NETWORK INC.
发明人： FUKAWA, Kazuhiko, A102 goushitsu , YOSHINO, Hitoshi , SUZUKI, Hiroshi
IPC分类号： H04B7/005 , H04L27/01 , H04B1/76
CPC分类号： H04L25/03273
摘要： Base-band signals obtained by asynchronously detecting received signals are sampled and the signals, are written in a buffer memory (11) as series of base-band signals samples. A most likelihood sequence estimating sec, tion (15) generates a desired symbol sequence corresponding to the samples read from the memory (11) and supplies the symbol sequence to a transversal filter (18) having characteristics esti. mated from the impulse response of the transmission line at the timings of the samples. A phase error detecting section (23) successively detects the phase errors between estimated received signals obtained and corresponding base-band signal samples. An offset correcting signal generating section (22) calculates an estimated offset angular frequency Δω e from the phase errors, generates an offset correcting signal having an angular frequency in the reverse direction of rotation, whose absolute value is equal to that of the estimated offset angular frequency Δω e , and supplies the offset correcting signal to a multiplier (21) for correction. The multiplier (21) corrects the offset angular frequency so as to cancel the angular frequency offset by multiplying the samples by the offset correcting signal. A subtractor (14) finds the difference between the corrected samples and estimated signals received from the transversal filter as estimated errors. The estimating section (15) finds the most likelihood information from the estimated errors and discriminates signals by using a most likelihood sequence estimating algorithm based on the most likelihood information.
摘要翻译：通过异步检测接收信号获得的基带信号被采样，并将信号作为一系列基带信号样本写入缓冲存储器（11）。估计秒（15）的最可能序列产生对应于从存储器（11）读取的样本的期望符号序列，并将符号序列提供给具有特征估计的横向滤波器（18）。在样本的定时从传输线的脉冲响应交配。相位误差检测部（23）连续检测所获得的估计接收信号与对应的基带信号样本之间的相位误差。偏移校正信号生成部（22）根据相位误差来计算估计的偏移角频率ΔTATA，生成具有反向旋转方向的角频率的偏移校正信号，其绝对值与估计偏移量的绝对值相等角度频率ΔTATA，并且将偏移校正信号提供给用于校正的乘法器（21）。乘法器（21）校正偏移角频率，以通过将采样乘以偏移校正信号来消除角频率偏移。减法器（14）找出校正样本与从横向滤波器接收的估计信号之间的差作为估计误差。估计部分（15）通过使用基于最可能信息的最可能序列估计算法从所估计的误差中找出最可能信息，并鉴别信号。

你已经成功收藏专利！

检索式保存成功!

IPRDB

热门服务

关于我们

友情链接

联系方式