| Patent application number | Description | Published |
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| 20080233965 | METHOD AND SYSTEM FOR ADAPTIVE ALLOCATION OF FEEDBACK RESOURCES FOR CQI AND TRANSMIT PRE-CODING - Aspects of a method and system for adaptive allocation of feedback resources for CQI and transmit pre-coding may include assigning a bandwidth and a feedback period to one or more CQI reporting units and a bandwidth and a feedback period to one or more PMI reporting units. One or more feedback messages may be generated based at least on channel state information associated with the bandwidth and the feedback period assigned to the one or more CQI reporting units and with the bandwidth and the feedback period assigned to the one or more PMI reporting units. The bandwidth and the feedback period of the CQI reporting units and/or the PMI reporting units may be adjusted dynamically and/or adaptively. Based on the channel state information or as a function of a feedback rate, the bandwidth and/or the feedback period may be assigned. | 09-25-2008 |
| 20080268862 | METHOD AND SYSTEM FOR BEST-M CQI FEEDBACK TOGETHER WITH PMI FEEDBACK - Aspects of a method and system for best-M CQI feedback together with PMI feedback may include generating a plurality of feedback messages, which may be communicated from a mobile station to a base station, wherein at least one of the generated plurality of feedback messages may be associated with each corresponding selected one of a plurality of Channel Quality Indicator (CQI) reporting units. The at least one of the generated feedback messages may comprise CQI information and Pre-coding Matrix Index (PMI) information, which may both be associated with the selected one of the plurality of CQI reporting units. At least one other of the generated plurality of feedback messages may comprise an aggregate CQI information, which is based on one or more of the plurality of CQI reporting units. | 10-30-2008 |
| 20080272953 | METHOD AND SYSTEM FOR CODEBOOK DESIGN FOR PRE-CODING TECHNIQUES - Aspects of a method and system for codebook design for pre-coding techniques may include generating one or more matrices whose matrix elements are from a constant amplitude signal constellation, wherein each of the one or more generated matrices may comprise one or more orthonormal columns, and one of the generated one or more matrices may be an identity matrix. Any two of the generated one or more matrices may be separated by at least a minimum pairwise distance. One or more pre-coding codebooks may be generated, each of which may comprise one or more codebook elements that may be of a same matrix rank. Each of the codebook elements may be generated from a subset of columns from one of the generated one or more matrices. A signal may be pre-coded for transmission using the one or more pre-coding codebooks. | 11-06-2008 |
| 20080273624 | METHOD AND SYSTEM FOR CQI/PMI FEEDBACK FOR PRECODED MIMO SYSTEMS UTILIZING DIFFERENTIAL CODEBOOKS - Aspects of a method and system for CQI/PMI feedback for precoded MIMO systems utilizing differential codebooks may include generating one or more feedback messages for one or more Channel Quality Indicator (CQI) reporting units based on at least channel state information associated with the one or more CQI reporting units. One or more differential feedback messages may be generated for one or more Pre-coding Matrix Index (PMI) reporting units based on at least channel state information associated with the one or more PMI reporting units, wherein the one or more PMI reporting units span a useable bandwidth. A bandwidth and a feedback period may be assigned to each of the one or more CQI reporting units and the one or more PMI reporting units to define the one or more CQI reporting units and the one or more PMI reporting units. | 11-06-2008 |
| 20090253381 | Method and System For Greedy User Group Selection With Range Reduction for FDD Multiuser MIMO Downlink Transmission With Finite-Rate Channel State Information Feedback - Aspects of a greedy search user group selection scheme with range reduction for FDD multiuser MIMO downlink transmission with finite-rate channel state information feedback are provided. The method may comprise receiving feedback information via a communication channel for a plurality of users in a frequency division duplex system. The system capacity may be maximized using the feedback information based on a signal from a single user within a reduced search range or based on the signal from the single user and at least one other signal from another user within a remaining portion of the search range. The feedback information may comprise quantized gain and/or direction of the channel state information of the users. | 10-08-2009 |
| 20090268833 | METHOD AND SYSTEM FOR PREDICTING CHANNEL QUALITY INDEX (CQI) VALUES FOR MAXIMUM LIKELIHOOD (ML) DETECTION IN A 2X2 MULTIPLE INPUT MULTIPLE OUTPUT (MIMO) WIRELESS SYSTEM - Aspects of a method and system for predicting CQI values for ML detection in a 2×2 MIMO system are presented. In one aspect of the system, a CQI value for a MIMO communication system may be computed based on a computed channel realization by reverse mapping the computed channel realization to a corresponding CQI value. Based on the computed CQI value, a coding rate may be selected. The coding rate may be selected from a lookup table, wherein the computed CQI value is utilized as an index to the lookup table. The reverse mapping may utilize a function, which is computed using radial basis function networks. In another aspect of the system, a joint mutual information value may be computed for the MIMO communication system. The joint mutual information value may be computed based on a Shannon mutual information value and a matched filter mutual information value. | 10-29-2009 |
| 20090268834 | METHOD AND SYSTEM FOR PREDICTING CHANNEL QUALITY INDEX (CQI) VALUES FOR MAXIMUM LIKELIHOOD (ML) DETECTION IN A KXK MULTIPLE INPUT MULTIPLE OUTPUT (MIMO) WIRELESS SYSTEM - Aspects of a method and system for predicting CQI values for ML detection in a K×K MIMO system are presented. In one aspect of the system, a CQI value for a K×K MIMO communication system may be computed by decomposing the K×K MIMO system into a series of 2×2 MIMO systems. For each 2×2 MIMO system a CQI value may be computed by reverse mapping a PER computed for the 2×2 MIMO system and an SNR value for a SISO communication system. By summing CQI values among the series of 2×2 MIMO systems a CQI value for the K×K MIMO system may be computed. Based on the computed CQI value for the K×K MIMO system, a coding rate may be selected. The selected coding rate may be selected to maximize a computed information throughput rate at a MIMO receiver that utilizes ML detection. | 10-29-2009 |
| 20110051828 | METHOD AND SYSTEM FOR AN EFFICIENT CHANNEL QUANTIZATION METHOD FOR MIMO PRE-CODING SYSTEMS - A method and system for processing communication signals is provided and may comprise, quantizing a channel estimate at a MIMO receiver onto a codebook based on a cost function, wherein the codebook comprises a plurality of unitary matrices. A codebook index may be fed back from the MIMO receiver to a MIMO transmitter, wherein the codebook index is associated with one of the plurality of unitary matrices that minimizes the cost function. The cost function may be minimized by choosing a smallest scalar cost from a plurality of scalar costs, wherein each one of the scalar costs is generated from one or more sums and one or more products of elements of a product matrix, and wherein the product matrix is generated from one of the plurality of unitary matrices, a matrix comprising the channel estimate, and their respective Hermitian Transposes. | 03-03-2011 |
| 20110164510 | METHOD AND SYSTEM FOR SELECTING A USER GROUP USING QUANTIZED CHANNEL STATE INFORMATION FEEDBACKS FROM MIMO CAPABLE MOBILE DEVICES - A mobile device estimates channel status information (CSI) for an associated single user downlink multiple-input multiple-output (MIMO) channel. The estimated CSI is quantized using a finite quantization resolution. The quantized CSI is communicated to the base station over a finite-rate feedback channel. Intended downlink data transmission is scheduled by the base station according to the transmitted CSI, and received by the mobile device, accordingly. The estimated CSI comprise generalized channel quality information such as channel capacity and channel direction. The base station selects a first user having a strongest channel capacity according to quantized CSI received from associated mobile devices. Beams orthogonal to a single user downlink MIMO channel of the selected first user are broadcasted. Quantized relative channel direction matrices and projected channel capacity are received from remaining mobile devices. A user having a strongest projected channel capacity is selected a second user for the user group. | 07-07-2011 |
| 20110164557 | METHOD AND SYSTEM FOR ITERATIVE DISCRETE FOURIER TRANSFORM (DFT) BASED CHANNEL ESTIMATION USING MINIMUM MEAN SQUARE ERROR (MMSE) TECHNIQUES - A method and system for iterative discrete Fourier transform (DFT) based channel estimation using minimum mean square error (MMSE) techniques are presented. Aspects of the method and system include a procedure for computing channel estimates in both the time domain and frequency domain (or mixed domain) using an iterative DFT method based on MMSE techniques. One aspect of the method and system may achieve low computational complexity and produce more accurate channel estimate values in low signal to noise ratio (SNR) regimes in comparison to conventional DFT-based channel estimation methods, which utilize least squares (LS) techniques. The method and system disclosed herein may be practiced in connection with a wide range of orthogonal frequency division multiplexing (OFDM) based systems, for example wireless local area networks (WLAN, for example IEEE 802.11 WLAN systems), and LTE systems. | 07-07-2011 |
| 20110164695 | METHOD AND SYSTEM FOR SELECTING A USER GROUP USING HYBRID-QUANTIZED CHANNEL DIRECTION INFORMATION FEEDBACKS FROM MIMO CAPABLE MOBILE DEVICES - A mobile device receives beams orthogonal to a single user downlink MIMO channel associated with a selected first user in a user group. The mobile device estimates relative channel direction information with respect to the received beams for an associated single user downlink MIMO channel. The estimated relative channel direction information is hybrid-quantized to generate a semi-orthogonal matrix transmitted to the base station over a finite-rate feedback link. The mobile device receives downlink data transmission according to the hybrid-quantized relative channel direction information. The base station receives multiple semi-orthogonal matrices from remaining mobile devices to generate a semi-orthogonal group for the selected first user. A mobile device having the strongest quantized projected channel capacity is selected from the generated semi-orthogonal group as a second user. Mutual channel capacity information for the selected first and second users is determined to schedule corresponding downlink data transmissions, accordingly. | 07-07-2011 |
| 20110165846 | METHOD AND SYSTEM FOR USING NON-UNIFORM CHANNEL QUANTIZATION FOR A FEEDBACK-BASED COMMUNICATION SYSTEM - A mobile device estimates channel state information (CSI) comprising, for example, CQI and/or SNR, for a downlink channel. The estimated CSI is non-uniformly quantized and transmitted to the base station over a finite-rate feedback channel. Different portions of the estimated CSI are quantized using different quantization step sizes, which are determined according to a performance metric function such as a channel capacity function of the estimated CSI. A quantization step size for a portion of the estimated CSI is increased if a low distribution probability is indicated by the portion of the estimated CSI. A quantization step size for a portion of the estimated CSI is decreased if a high distribution probability is indicated. The mobile device quantizes the estimated CSI using the determined quantization step sizes to transmit to the base station over the finite-rate feedback channel. Downlink data transmission is received according to the transmitted CSI. | 07-07-2011 |
