Abstract: Techniques and devices for antenna selection in a multiple-input-multiple-output (MIMO) system, in which communication is between a transmitter having a first plurality of radio-frequency (RF) chains coupled to a first plurality of antennas and a receiver having a second plurality of RF chains coupled to a second plurality of antennas, are provided. Techniques include receiving consecutive sounding packets each have a training symbol and that collectively sound a full-size channel for the MIMO system. A sub-channel estimate for each sounding packet can then be determined based on various factors, such as a known power level rule and gain factor. Scaling factors may be applied to each of these sub-channel estimates to produce a scaled sub-channel estimates.

Abstract: A beamforming technique used in a MIMO wireless transmission system determines a transmitter beamforming steering matrix using a matrix equalizer of a transmitter or a receiver within the MIMO communication system, to thereby increase the speed and/or to decrease the processing needed to implement effective beamforming within the transmitter of the communication system. While this beamforming technique may not provide the best possible set of steering coefficients that obtain the best possible transmission and reception in the communication system, this technique can provide increased performance over no beamforming without significantly increasing the processing overhead of the transmission system. This beamforming technique can used when a transmitter, with multiple transmitter antennas, is used to communicate with one or with multiple receivers within the communication system.

Abstract: An orthogonal frequency division multiplex (OFDM) transmitter may adaptively load each sub-carrier, buffering less than an OFDM frame in order to reduce hardware requirements and latency. The transmitter may use feedback information from the receiver regarding the quality of the sub-carriers. In addition, combining repetition and puncturing to achieve a desired date rate per class further reduces hardware by simplifying or even eliminating an interleaver. Additional mitigation and even performance enhancement techniques are incorporated to address inter-class boundaries within an OFDM frame, such as introducing transition classes. Channel state information may be reported in various formats including full bitmap, changed subchannels, and reported bad subchannels.

Abstract: The invention relates to a weighting circuit for a receiver (1), which is designed to receive a multi-carrier signal consisting of carrier signals. According to the invention, the carrier signals are weighted by the weighting circuit (18) in such a way that the parasitic signal energy has the same intensity in all weighted carrier signals. In a preferred embodiment of the invention, the weighting circuit comprises at least one multiplier that multiplies an assigned a carrier signal by a stored weighting co-efficient. The stored weighting coefficients constitute reliability information for the various carrier signals.

Abstract: The invention is directed to a multi-bit digital signal isolation system including a plurality of micro-transformers, each having a primary winding and a secondary winding, a transmitter circuit receiving a multi-bit signal and transmitting an encoded logic signal across the plurality of micro-transformers corresponding to the multi-bit signal, the primary winding of each micro-transformer receiving a signal corresponding to one of at least three possible states, and a receiver circuit receiving the encoded logic signal from the secondary windings of the plurality of transformers, decoding the encoded logic signal and reconstructing the received multi-bit signal based upon the decoded signal.

Abstract: A method of transmitting power information in a wireless communication system is provided. The method includes: determining energy per resource element (RE) to which a reference signal or data is mapped for downlink transmission; and transmitting power information of the reference signal and the data, wherein the reference signal comprises a channel state indication-reference signal (CSI-RS) for channel state measurement, power information of the CSI-RS is denoted by a ratio of power for a CSI-RS RE and power for a data RE of an orthogonal frequency division multiplexing (OFDM) symbol on which only data is transmitted or power for a cell-specific RS (CRS) RE used for channel state measurement and data demodulation of different OFDM symbols.

Abstract: The present invention relates to the field of receiving data and/or demodulating a data transmission signal. The present invention provides a method of and/or device for determining a data signal imposed on a phase jitter modulation signal. In one form, the invention relates to the field of Radio Frequency Identification (RFID), and the transmission of data between a tag and an interrogator.

Abstract: According to an aspect of an embodiment, a communication system includes a transmission apparatus with a coding section that generates multi-level-coded signals and transmits the multi-level-coded signals; and a deskew signal generation section that generates and transmits a deskew signal related to the multi-level-coded signals. The communication system also includes a receiving apparatus with a decoding section that decodes the multi-level-coded signals to generate decoded signals, and a deskew processing section that performs deskew processing for compensating skew among the decoded signals of the multiple channels. The deskew signal generation section generates the deskew signal that has been framed by extracting a part of the data from each of the channels of the input signals, adding framing data for enabling a receiving apparatus to recognize which channel the extracted data has been extracted from, and performing rate conversion.

Abstract: A procedure for compensating the DC component inherent in any radio frequency chain making it possible from a single measurement, generally located in the digital stage, to determine a set of multiple compensation values that must be applied to multiple compensation points of the analogue chain. The compensation values are calculated by an iterative process converging towards a cancellation of the DC component and avoid saturating amplification components and components of the analogue digital converter.

Abstract: A system for and method of removing one or more unwanted inband signals from a received communications signal is described. The inband signal or signals may comprise noise, interference signals, or any other unwanted signals that impact the quality of the underlying communications. A receiver receives a communication signal, the received communication signal including the desired communication signal and one or more inband signals. A signal processor processes the received signal to form an estimate of the desired communication signal and an estimate of the inband signals. The estimate of the inband signals is thereby removed from the received signal. The estimate of the desired communication signal and the estimate of the inband signals are formed without prior knowledge of characteristics of the inband signals and without obtaining a copy of any of the inband signals from any source other than the received signal.

Abstract: Methods and apparatus for initially decoding a frame control header (FCH) in an orthogonal frequency-division multiplexing (OFDM) or orthogonal frequency division multiple access (OFDMA) system in an effort to accurately determine the downlink frame prefix (DLFP) such that the remainder of an OFDM/A frame may be properly decoded are provided. Used, for example, when boosting factors applied in the transmitter to various elements of the OFDM/A frame and/or available pilots for the FCH are unknown, such methods may utilize a preamble channel estimate, the FCH pilots, or a combination thereof.

Abstract: Systems and methods are described that may be used to detect and correct carrier phase offset in a signal. A phase offset corrector receives an equalized signal representative of a quadrature amplitude modulated signal and derives a phase-corrected signal from the equalized signal. The equalized signal is sliced to obtain real and imaginary sequences and a frame synchronizer performs a correlation of the real and imaginary sequences with corresponding parts of a stored frame-sync pseudo-random sequence. Phase correction is based on the maximum real and imaginary values of the correlation. The signal is typically quadrature amplitude modulated signal is modulated using punctured trellis codes. Quadrature phase shift keying modulation, 16-QAM, 64-QAM and other QAM schemes may be used.

Abstract: Presently disclosed is a method for reducing interference in a wireless distributed antenna systems. In an embodiment, interference is reduced by selectively placing a first wireless remote unit in a reduced signal interference mode. A controller sends a signal, such as a reverse link power-down signal, to the first remote unit after detecting less than a threshold incoming signal strength at the first remote unit. In an alternative embodiment, the controller requests that a given remote unit switch to the reduced signal interference mode when the controller is receiving signals from a mobile station through at least two different remote units.

Abstract: A method and a device for feeding back and receiving downlink channel information are disclosed, whereby spectrum utilization ratio of downlink channel information feedback is enhanced. According to the present invention, a wireless terminal superposes an uplink user information sequence with spectrum-spread downlink channel information before transmission. A network side de-spreads a received signal before estimating the downlink channel information, and then detects the user information sequence after subtracting the estimated downlink channel information from the received signal. An orthogonal code can be employed to spread the spectrum of the downlink channel information. The wireless terminal and base station use a plurality of antennas for transmission and reception.

Abstract: A TPS decoder for a DVB-T digital television system includes an input signal estimator, a masking device, a vector index determinator and a lookup table device. The input signal estimator receives a plurality of frequency-domain input signals and a plurality of channel measure signals to thereby produce a plurality of estimated input signals. The masking device performs a masking operation on the estimated input signals to thereby produce a plurality of masking signals. The vector index determinator is based on the masking signals to determine a vector index corresponding to the frequency-domain input signals. The lookup table device is based on the vector index to produce a codeword.

Abstract: An adaptive equalizer comprises an adjustable equalizer circuit that allows to enhance the frequency dependence of contents of the transmitted signals which suffer from losses in the connected transmission channel. A blind equalization tuning procedure is proposed that operates without knowledge about the characteristic of transmission channel. Phase positions of transitions in the equalized signal are detected. A digital post-processing circuit evaluates a measure for spread of the detected phase positions of transitions, accumulated over a plurality of the symbol periods. The digital post-processing circuit controls the adjustable equalizer, setting the adjustable equalizer to a setting wherein the detected spread is minimized.

Abstract: A tone selection module selects tones suitable for use in an orthogonal frequency division multiplexing (OFDM) data transmission device based on several constraints. These constraints include number of available tones, modulation type, and code rate. The OFDM device may use either wired or wireless transmission.

Abstract: The present invention is a method and apparatus for improving the performance of spatial temporal turbo channel coding (STTCC) used in multiple-input multiple-output (MIMO) wireless communication systems called eigen-STTCC (E-STTCC) that employs eigen-beamforming to make use of orthogonal eigen streams in the MIMO channel. Singular value decomposition (SVD) is applied to the channel matrix producing a linear precoding matrix containing the orthonormal basis for the eigen streams. In a first embodiment, the turbo encoded codeword containing concatenated systematic and parity bits is precoded with the linear precoding matrix such that the systematic bits are transmitted over the eigen streams with highest power. In a second embodiment, the codeword is made up of interleaved systematic bits and parity bits prior to eigen beamform preceding, effectively interleaving the systematic and data bits spatially over the eigen streams.

Abstract: A method of noise mitigation in a multi-carrier communication system includes receiving a signal from a decision device, determining whether synchronization symbol update is enabled, updating at least one of frequency-domain equalizer (FEQ) coefficients or digital echo canceller (DEC) coefficients in synchronization symbol periods if the synchronization symbol update is enabled, determining whether data symbol update is performed if the synchronization symbol update is not enabled, determining whether a flag associated with the signal is set if the data symbol update is not performed, and updating at least one of FEQ or DEC coefficients associated with the signal in synchronization symbol periods if the flag is set.

Abstract: The present invention relates to receiver apparatuses and methods of controlling weight adaptation in a receiver of a code multiplex telecommunications system with orthogonal spreading codes, wherein received discrete time signal samples are chip-level filtered by using a first equalizing step. Additionally, the received discrete time signal samples are delayed by a time period corresponding to a data symbol and used in a second equalizing step. Symbol estimates obtained from the first equalizing step are non-linearly filtered and used as a desired response for the second equalizing step in the following symbol period, wherein equalizer weights adapted in the second equalizing step are used for the first equalizing step. Alternatively, the second equalizing step may be dispensed with and weight adaptation may be incorporated in a single equalizing step.