| Patent application number | Description | Published |
|---|
| 20080291989 | Crosstalk Estimation Methods and Apparatus Using Auxiliary Time-Domain Signals - Techniques are disclosed for measuring crosstalk between at least two communication channels of a communication system. A receiver of the system receives a signal over a given one of the communication channels from a transmitter of the system. The receiver correlates the received signal with a sequence of time-domain signals associated with another of the communication channels, and generates a measure of crosstalk between the given communication channel and the other communication channel based on the correlation between the received signal and the sequence of time-domain signals. The sequence of time-domain signals may be selected from a designated set of M-sequences. | 11-27-2008 |
| 20080316910 | Complex vector quantization codebook for use in downlink multi-user MIMO mobile broadcast systems - A wireless communications device having a complex vector quantization codebook for use in a downlink multi-user MIMO (multiple-input-multiple-output) mobile broadcast system with feedback enables the interference between data simultaneously sent by the base station to a plurality of mobile terminals to be reliably minimized. The codebook contains many subsets of code vectors that are substantially mutually (i.e., pairwise) orthogonal, or almost orthogonal, to each other. With use of such a codebook, a base station can transmit simultaneously to subsets of mobile terminals associated with these subsets of code vectors with minimal interference therebetween. | 12-25-2008 |
| 20080316975 | Method and Apparatus for Quantizing Complex Vectors in Communication System - Improved techniques are disclosed for quantizing complex vectors in communication systems. For example, a method includes the following steps. At least one complex vector representative of at least one element of a communication system is obtained. A codeword that approximates the complex vector is identified. The identified codeword is a codeword, from a set of codewords, wherein a real part of a product of the codeword and a scaled version of the complex vector is about maximal over the set of codewords. The scaled version of the complex vector is the product of the complex vector and a constant from a set of constants. In one embodiment, the element of the communication system that the complex vector represents is a channel between a base station and a user terminal in the communication system. | 12-25-2008 |
| 20090034668 | METHOD AND APPARATUS FOR SYNCHRONIZING A RECEIVER - Various embodiments generally relate to a method for synchronizing a receiver, said method including receiving a stream that includes a cyclic extension, estimating a size of the cyclic extension, extracting an amount of the stream according to the estimated size, and comparing the extracted amount to the stream to determine thereby a portion of the stream likely to include a symbol start point. | 02-05-2009 |
| 20090067530 | Providing feedback in a MIMO system - There is provided a system and method of operating a multiple-input multiple-output (MIMO) receiver with N antennas in a wireless communication system. The method includes measuring N vectors, each vector defining channel transfer coefficients between M antennas of a transmitter and a corresponding antenna of the receiver. Additionally, a vector in a linear space generated by the N measured vectors is selected and quantized values of less than M components of the selected vector are fed back to the transmitter. | 03-12-2009 |
| 20090116582 | INTERPOLATION METHOD AND APPARATUS FOR INCREASING EFFICIENCY OF CROSSTALK ESTIMATION - Techniques are disclosed that efficiently obtain channel crosstalk estimates in DSL systems and other communication systems that may include unsynchronized channels. For example, a method includes obtaining a first set of estimated measures of crosstalk for a first portion of a plurality of communication channels over which data signals are to be transmitted from a transmitter to a plurality of receivers, and interpolating a second set of estimated measures of crosstalk for a second portion of the plurality of communication channels based on the first set of estimated measures of crosstalk. The first portion of the plurality of communication channels may be a subset of the plurality of communication channels and the second portion of the plurality of communication channels is a remainder of the plurality of communication channels. Each estimated measure of crosstalk may relate to at least one tone associated with at least one of the plurality of communication channels. | 05-07-2009 |
| 20090245081 | Fast Seamless Joining of Channels in a Multi-Channel Communication System - At least one channel is joined to a group of active channels in a communication system by transmitting control signals to configure respective customer premises equipment (CPE) of the active channels into a joining mode of operation, and transmitting a joining signature sequence to CPE of the joining channel over a downstream data signal path of the joining channel. A central office (CO) or other access node of the system receives correlation results from respective active channel CPE, estimates crosstalk from the joining channel into the active channels based on the correlation results, configures a precoder based on the estimated crosstalk, and adds the joining channel to the group of active channels. The channels may comprise respective subscriber lines of a DSL communication system. | 10-01-2009 |
| 20100074356 | Methods for precoding signals for transmission in wireless MIMO system - Methods discussed herein provide more efficient precoding matrices for precoding signals prior to transmission. The methods discussed herein improve throughput in wireless MIMO systems. Methods discussed herein are applicable to frequency division duplexing (FDD) systems, time division duplexing (TDD) systems as well as other wireless communication systems. | 03-25-2010 |
| 20100203912 | Methods for reducing inter-cell interference by precoding signals for transmission in wireless MIMO system - Methods for suppressing inter-cell interference during data transmission using a preceding matrix are provided. Inter-cell interference is suppressed by precoding data (or information) signals for transmission from base station to mobile or vice versa. Methods according to example embodiments also increase intra-cell data transmission rates. The precoding matrix is generated based on estimated channel coefficients for propagation channels between a base station and mobiles inside and outside the base station's coverage area. | 08-12-2010 |
| 20110075617 | Pilot signal allocation method and apparatus for multi-user wireless systems - A construction is provided for uplink pilot signals in a cellular network. Three sets of pilot signals are defined, having orthogonality properties that lead to reduced inter-cell interference. In example embodiments, the network has a reuse factor of 3 for pilot signals, with sets U, V, and W of pilot signals assigned to cells in respective reuse classes. The pilots of each set form an orthogonal basis. Some pilots of each class, i.e. those which will generally be assigned to mobile stations near the cell edges, will also form an orthogonal basis with some pilots of each of the other classes. | 03-31-2011 |
