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111. 发明申请

US20080285488A1 MIMO WLAN SYSTEM 有权
标题翻译： MIMO WLAN系统
公开(公告)号：US20080285488A1
公开(公告)日：2008-11-20
申请号：US12112728
申请日：2008-04-30
申请人： J. Rodney Walton , Mark S. Wallace , John W. Ketchum , Steven J. Howard
发明人： J. Rodney Walton , Mark S. Wallace , John W. Ketchum , Steven J. Howard
IPC分类号： H04J3/00 , H04K1/10
CPC分类号： H04L5/0048 , H04B7/022 , H04B7/0421 , H04B7/043 , H04B7/0443 , H04B7/0669 , H04B7/0689 , H04B7/0697 , H04B7/0854 , H04B7/0871 , H04L1/0003 , H04L1/0009 , H04L1/0017 , H04L1/0025 , H04L1/0059 , H04L1/0061 , H04L1/0069 , H04L1/0071 , H04L1/0606 , H04L1/0625 , H04L1/0656 , H04L1/08 , H04L1/16 , H04L1/1887 , H04L5/0023 , H04L25/0204 , H04L25/0226 , H04L25/0228 , H04L25/0248 , H04L25/03343 , H04L27/2602 , H04L27/2607 , H04L27/2647 , H04L2025/03414 , H04L2025/03426 , H04W28/20 , H04W28/22 , H04W52/42 , H04W52/50 , H04W72/12 , H04W84/12
摘要： A multiple-access MIMO WLAN system that employs MIMO, OFDM, and TDD. The system (1) uses a channel structure with a number of configurable transport channels, (2) supports multiple rates and transmission modes, which are configurable based on channel conditions and user terminal capabilities, (3) employs a pilot structure with several types of pilot (e.g., beacon, MIMO, steered reference, and carrier pilots) for different functions, (4) implements rate, timing, and power control loops for proper system operation, and (5) employs random access for system access by the user terminals, fast acknowledgment, and quick resource assignments. Calibration may be performed to account for differences in the frequency responses of transmit/receive chains at the access point and user terminals. The spatial processing may then be simplified by taking advantage of the reciprocal nature of the downlink and uplink and the calibration.
摘要翻译：采用MIMO，OFDM和TDD的多接入MIMO WLAN系统。系统（1）使用具有多个可配置传输信道的信道结构，（2）支持基于信道条件和用户终端能力可配置的多种速率和传输模式，（3）采用具有多种类型（4）实现速率，定时和功率控制环路，实现系统正常运行，（5）采用随机接入方式进行系统接入，由用户终端，快速确认和快速的资源分配。可以执行校准以考虑接入点和用户终端处的发射/接收链的频率响应的差异。然后可以通过利用下行链路和上行链路的相互性质和校准来简化空间处理。

112. 发明授权

US07372896B2 Iterative detection and decoding for a MIMO-OFDM system 有权
标题翻译： MIMO-OFDM系统的迭代检测和解码
公开(公告)号：US07372896B2
公开(公告)日：2008-05-13
申请号：US11557662
申请日：2006-11-08
申请人： Bjorn Bjerke , John W. Ketchum , Jay Rodney Walton
发明人： Bjorn Bjerke , John W. Ketchum , Jay Rodney Walton
IPC分类号： H04B1/69
CPC分类号： H04L1/005 , H04B7/0413 , H04B7/0854 , H04L1/0003 , H04L1/0009 , H04L1/0059 , H04L1/0066 , H04L1/0071 , H04L1/06 , H04L5/0023 , H04L25/03171 , H04L25/03305 , H04L25/03891 , H04L25/067 , H04L27/2647
摘要： Techniques to iteratively detect and decode data transmitted in a wireless (e.g., MIMO-OFDM) communication system. The iterative detection and decoding is performed by iteratively passing soft (multi-bit) “a priori” information between a detector and a decoder. The detector receives modulation symbols, performs a detection function that is complementary to the symbol mapping performed at the transmitter, and provides soft-decision symbols for transmitted coded bits. “Extrinsic information” in the soft-decision symbols is then decoded by the decoder to provide its extrinsic information, which comprises the a priori information used by the detector in the detection process. The detection and decoding may be iterated a number of times. The soft-decision symbols and the a priori information may be represented using log-likelihood ratios (LLRs). Techniques are provided to reduce the computational complexity associated with deriving the LLRs, including interference nulling to isolate each transmitted signal and “dual-maxima” approximation.
摘要翻译：用于迭代地检测和解码在无线（例如，MIMO-OFDM）通信系统中发送的数据的技术。迭代检测和解码通过在检测器和解码器之间迭代地传递软（多位）“先验”信息来执行。检测器接收调制符号，执行与在发射机处执行的符号映射互补的检测功能，并为发送的编码比特提供软判决符号。软判决符号中的“外在信息”然后由解码器解码以提供其外在信息，其包括检测器在检测过程中使用的先验信息。可以重复检测和解码多次。可以使用对数似然比（LLR）来表示软判决符号和先验信息。提供技术以减少与导出LLR相关联的计算复杂度，包括干扰归零以隔离每个发射信号和“双最大值”近似。

113. 发明申请

US20070298742A1 METHOD AND SYSTEM FOR PROVIDING BEAMFORMING FEEDBACK IN WIRELESS COMMUNICATION SYSTEMS 有权
标题翻译：在无线通信系统中提供波束形成反馈的方法和系统
公开(公告)号：US20070298742A1
公开(公告)日：2007-12-27
申请号：US11768329
申请日：2007-06-26
申请人： John W. Ketchum , Sanjiv Nanda , Arnaud Meylan , Shravan K. Surineni
发明人： John W. Ketchum , Sanjiv Nanda , Arnaud Meylan , Shravan K. Surineni
IPC分类号： H04B1/18
CPC分类号： H04B7/0643 , H04B7/0421 , H04B7/0617 , H04B7/0634 , H04B7/0636 , H04L25/0204 , H04L25/0228 , H04L25/03343 , H04L2025/03414 , H04L2025/03426 , H04L2025/03802
摘要： Techniques to support beamforming for stations in a wireless network are described. In one aspect, a station may support beamforming with implicit feedback or explicit feedback by having capabilities to transmit and receive sounding frames, respond to training request by sending a sounding frame, and respond to request for explicit feedback. In one design of explicit beamforming, the station may send a first frame with a request for explicit feedback and may also send a Null Data Packet (NDP) having at least one training field but no data field. The station may receive a second frame with the explicit feedback, which may be derived based on the NDP. The station may derive steering information (e.g., steering matrices) based on the explicit feedback and may then send a steered frame with beamforming based on the steering information. The station may also perform implicit beamforming using NDP for sounding.
摘要翻译：描述了支持无线网络中的站的波束成形的技术。在一个方面，站可以通过具有发送和接收探测帧的能力来支持具有隐式反馈或显式反馈的波束成形，通过发送探测帧来响应训练请求，以及响应对显式反馈的请求。在显式波束形成的一种设计中，站可以发送具有对显式反馈的请求的第一帧，并且还可以发送具有至少一个训练场但不包括数据场的空数据分组（NDP）。该站可以接收具有显式反馈的第二帧，其可以基于NDP导出。基站可以基于显式反馈导出转向信息（例如，导引矩阵），然后可以基于转向信息发送具有波束成形的转向帧。该站还可以使用NDP进行声音执行隐式波束成形。

114. 发明授权

US07221956B2 Power control for partial channel-state information (CSI) multiple-input, multiple-output (MIMO) systems 有权
标题翻译：部分信道状态信息（CSI）多输入多输出（MIMO）系统的功率控制
公开(公告)号：US07221956B2
公开(公告)日：2007-05-22
申请号：US11049319
申请日：2005-02-01
申请人： Irina Medvedev , Jay R. Walton , John W. Ketchum
发明人： Irina Medvedev , Jay R. Walton , John W. Ketchum
IPC分类号： H04B7/00
CPC分类号： H04B7/0417 , H04B7/0619 , H04L1/0001 , H04L1/06 , H04W52/42
摘要： Techniques for controlling the transmit power for a number of data streams in a wireless multi-channel (e.g., MIMO) communication system. In one method, a number of received symbol streams are initially processed in accordance with a particular (e.g., CCMI, CCMI-SC, MMSE, or MMSE-SC) receiver processing technique to provide a number of detected data streams. The post-detection SNRs of the detected data streams are estimated, and each SNR that exceeds a setpoint is identified. This setpoint may correspond to (1) the SNR needed to achieve the maximum allowed spectral efficiency or (2) the target SNR needed to achieve a specified spectral efficiency. A new (or adjusted) transmit power for each detected data stream associated with a post-detection SNR that exceeds the setpoint is determined and used for the data stream. Different power control schemes are provided for different classes of receiver processing techniques with different characteristics.
摘要翻译：用于在无线多信道（例如，MIMO）通信系统中控制多个数据流的发射功率的技术。在一种方法中，根据特定（例如，CCMI，CCMI-SC，MMSE或MMSE-SC）接收机处理技术最初处理多个接收到的符号流，以提供多个检测到的数据流。估计检测到的数据流的检测后SNR，并且识别超过设定点的每个SNR。该设定点可以对应于（1）实现最大允许频谱效率所需的SNR或（2）实现特定频谱效率所需的目标SNR。确定与用于超过设定点的检测后SNR相关联的每个检测到的数据流的新（或调整的）发射功率并将其用于数据流。为不同类型的具有不同特性的接收机处理技术提供不同的功率控制方案。

115. 发明授权

US07206354B2 Calibration of downlink and uplink channel responses in a wireless MIMO communication system 有权
标题翻译：无线MIMO通信系统中下行链路和上行链路信道响应的校准
公开(公告)号：US07206354B2
公开(公告)日：2007-04-17
申请号：US10783175
申请日：2004-02-19
申请人： Mark S. Wallace , John W. Ketchum , J. Rodney Walton , Steven J. Howard
发明人： Mark S. Wallace , John W. Ketchum , J. Rodney Walton , Steven J. Howard
IPC分类号： H04B7/02 , H04K1/10
CPC分类号： H04B7/0421 , H04B17/20 , H04B17/21 , H04L25/03343 , H04L2025/03375 , H04L2025/03802
摘要： The downlink and uplink are calibrated to account for differences in the responses of transmit and receive chains at an access point and a user terminal. For initial calibration, the access point and user terminal transmit MIMO pilots on the downlink and uplink, which are used to derive channel estimates including the responses of the applicable transmit/receive chains. Correction matrices {circumflex over (K)}ap and {circumflex over (K)}ut are derived based on these channel estimates and thereafter used by the access point and user terminal, respectively. For follow-on calibration, one entity transmits a MIMO pilot and a steered reference. The other entity derives a first transmit matrix based on the steered reference and a second transmit matrix based on the MIMO pilot and calibration error matrices Qap and Qut, which contain estimates of the errors in {circumflex over (K)}ap and {circumflex over (K)}ut, respectively. Qap and Qut may be iteratively adjusted based on an adaptive procedure to minimize the errors between the two transmit matrices.
摘要翻译：校准下行链路和上行链路以考虑在接入点和用户终端处的发射和接收链的响应的差异。对于初始校准，接入点和用户终端在下行链路和上行链路上传输MIMO导频，用于导出包括适用发射/接收链的响应的信道估计。基于这些信道估计导出校正矩阵K ap和> ut分别由接入点和用户终端使用。对于后续校准，一个实体发送MIMO导频和转向引用。另一个实体基于导向基准导出第一发射矩阵，并且基于MIMO导频和校准误差矩阵Q∈和> ut ut ut ut ut ut ut ut ut ut ut ut ut ut ut ut and ut ut and and and and and and and and and and and and and 的错误分别为K＆lt; ap＆gt;和＆lt;＆lt; ut＆lt; / SUB＆gt ;. 可以基于自适应过程来迭代地调整Q＆lt; N＆gt;和＆lt; ut＆lt; / SUB＆gt;以最小化两个发送矩阵之间的误差。

116. 发明授权

US07197084B2 Precoding for a multipath channel in a MIMO system 有权
标题翻译： MIMO系统中多径信道的预编码
公开(公告)号：US07197084B2
公开(公告)日：2007-03-27
申请号：US10108616
申请日：2002-03-27
申请人： John W. Ketchum , Bjorn A. Bjerke
发明人： John W. Ketchum , Bjorn A. Bjerke
IPC分类号： H04K1/02 , H04L25/03 , H04L25/49
CPC分类号： H04B7/0413 , H04B7/005 , H04B7/043 , H04B7/0443 , H04B7/0626 , H04L25/03057 , H04L25/03343
摘要： Techniques for preceding data for a multipath channel in a MIMO system. In one method, data is coded in accordance with one or more coding schemes to provide coded data, which is further modulated (i.e., symbol mapped) in accordance with one or more modulation schemes to provide modulation symbols. An estimated response of the MIMO channel is obtained (e.g., provided by a receiver), and an equivalent channel response is derived based on the estimated MIMO channel response and a response of a feed-forward filter of a decision feedback equalizer. The modulation symbols are then precoded based on the equivalent channel response to provide precoded symbols, which are further preconditioned based on the estimated MIMO channel response (e.g., using spatio-temporal pulse-shaping) to provide preconditioned symbols for transmission over the MIMO channel. The feed-forward filter may be adapted based on a minimum mean square error (MMSE) criterion.
摘要翻译： MIMO系统中多路径信道的先前数据的技术。在一种方法中，根据一个或多个编码方案对数据进行编码，以提供编码数据，根据一个或多个调制方案进一步调制（即，符号映射）以提供调制符号。获得MIMO信道的估计响应（例如，由接收机提供），并且基于估计的MIMO信道响应和判决反馈均衡器的前馈滤波器的响应导出等效信道响应。然后基于等效信道响应对调制符号进行预编码，以提供预编码符号，这些符号基于估计的MIMO信道响应（例如，使用时空脉冲整形）进一步预处理，以提供用于在MIMO信道上传输的预处理符号。可以基于最小均方误差（MMSE）准则来适配前馈滤波器。

117. 发明授权

US07164649B2 Adaptive rate control for OFDM communication system 有权
标题翻译： OFDM通信系统的自适应速率控制
公开(公告)号：US07164649B2
公开(公告)日：2007-01-16
申请号：US10001178
申请日：2001-11-02
申请人： Jay R. Walton , John W. Ketchum , Steven J. Howard , Mark Wallace
发明人： Jay R. Walton , John W. Ketchum , Steven J. Howard , Mark Wallace
IPC分类号： H04J11/00 , H04L1/00
CPC分类号： H04L1/0015 , H04L1/0002 , H04L1/0003 , H04L1/0009 , H04L1/0025 , H04L1/0026 , Y02D50/10
摘要： Techniques to adaptively control the rate of a data transmission in a wireless (e.g., OFDM) communication system. In an aspect, various types of metrics may be derived and used to select the proper rate for the data transmission. Some types of metrics relate to different characteristics of the communication channel, such as SNR, frequency selectivity, time selectivity, and so on. One type of metric relates to the performance of the data transmission. In another aspect, the various types of metrics may be used in different manners to adaptively control the rate. Some metrics may be used for open-loop control of the rate, other metrics may be used for closed-loop control, and some may be used for both. For example, the channel metrics may be used to determine or select the rate, and the performance metrics may be used to determine whether or not to adjust the rate.
摘要翻译：技术来自适应地控制无线（例如，OFDM）通信系统中的数据传输速率。在一方面，可以导出各种类型的度量，并且用于选择数据传输的适当速率。一些类型的度量涉及通信信道的不同特性，例如SNR，频率选择性，时间选择性等。一种类型的度量涉及数据传输的性能。在另一方面，可以以不同的方式使用各种类型的度量来自适应地控制速率。某些度量可用于速率的开环控制，其他度量也可用于闭环控制，一些可用于两者。例如，可以使用信道度量来确定或选择速率，并且可以使用性能度量来确定是否调整速率。

118. 发明授权

US07095709B2 Diversity transmission modes for MIMO OFDM communication systems 有权
公开(公告)号：US07095709B2
公开(公告)日：2006-08-22
申请号：US10179439
申请日：2002-06-24
申请人： Jay R. Walton , John W. Ketchum
发明人： Jay R. Walton , John W. Ketchum
IPC分类号： H04J11/00
CPC分类号： H04L5/0028 , H04B7/04 , H04B7/0669 , H04B7/0678 , H04B7/0697 , H04L1/0001 , H04L1/0618 , H04L5/0007 , H04L5/0016 , H04L5/0023
摘要： Techniques for transmitting data using a number of diversity transmission modes to improve reliability. At a transmitter, for each of one or more data streams, a particular diversity transmission mode is selected for use from among a number of possible transmission modes. These transmission modes may include a frequency diversity transmission mode, a Walsh diversity transmission mode, a space time transmit diversity (STTD) transmission mode, and a Walsh-STTD transmission mode. Each diversity transmission mode redundantly transmits data over time, frequency, space, or a combination thereof. Each data stream is coded and modulated to provide modulation symbols, which are further processed based on the selected diversity transmission mode to provide transmit symbols. For OFDM, the transmit symbols for all data streams are further OFDM modulated to provide a stream of transmission symbols for each transmit antenna used for data transmission.

119. 发明授权

US07072413B2 Method and apparatus for processing data for transmission in a multi-channel communication system using selective channel inversion 有权
公开(公告)号：US07072413B2
公开(公告)日：2006-07-04
申请号：US09881610
申请日：2001-06-14
申请人： Jay R. Walton , John W. Ketchum
发明人： Jay R. Walton , John W. Ketchum
IPC分类号： H04L1/02
CPC分类号： H04B7/0417 , H04B7/0439 , H04B7/0615 , H04B7/0632 , H04B7/0647 , H04B7/0891 , H04L1/0003 , H04L1/0009 , H04L1/0015 , H04L1/0019 , H04L1/0068 , H04L1/06 , H04L5/0023 , H04L5/0037 , H04L5/0044 , H04L5/0046 , H04L5/006 , H04L5/0091 , H04L5/023 , H04L5/06 , H04L25/0204 , H04L25/0228 , H04L25/0244 , H04L25/0248 , H04L25/03159 , H04L25/03343 , H04L27/2608 , H04L2001/0096 , H04L2025/03414 , H04L2025/03426 , H04L2025/03802 , H04W52/24 , H04W52/346 , H04W52/42
摘要： Techniques to process data for transmission over multiple transmission channels. The available transmission channels are segregated into one or more groups, and the channels in each group are selected for use for data transmission. Data for each group is coded and modulated based on a particular coding and modulation scheme to provide modulation symbols, and the modulation symbols for each selected channel are weighted based on an assigned weight. The weighting “inverts” the selected channels such that they achieve similar received SNRs. With selective channel inversion, only “good” channels in each group having SNRs at or above a particular threshold are selected, “bad” channels are not used, and the total available transmit power for the group is distributed across the good channels in the group. Improved performance is achieved by using only good channels in each group and matching each selected channel's received SNR to the required SNR.

120. 发明授权

US07020482B2 Reallocation of excess power for full channel-state information (CSI) multiple-input, multiple-output (MIMO) systems 有权
公开(公告)号：US07020482B2
公开(公告)日：2006-03-28
申请号：US10056275
申请日：2002-01-23
申请人： Irina Medvedev , Jay Rod Walton , John W. Ketchum
发明人： Irina Medvedev , Jay Rod Walton , John W. Ketchum
IPC分类号： H04B7/00
CPC分类号： H04W52/346 , H04B7/0443 , H04W24/00 , H04W52/241 , H04W52/267 , H04W52/50 , H04W72/00
摘要： Techniques to allocate the total transmit power to the transmission channels in a multi-channel communication system such that higher overall system spectral efficiency and/or other benefits may be achieved. The total transmit power may be initially allocated to the transmission channels based on a particular power allocation scheme (e.g., the water-filling scheme). The initial allocation may result in more power being allocated to some transmission channels than needed to achieve the required SNR (e.g., the SNR needed to achieve the maximum allowed data rate), which would then result in these transmission channels being operated in the saturation region. In such situations, the techniques reallocate the excess transmit power of transmission channels operated in the saturation region to other transmission channels operated below the saturation region. In this way, higher data rate may be achieved for the “poorer” transmission channels without sacrificing the performance of the “better” transmission channels.

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