| Patent application number | Description | Published |
|---|
| 20090059961 | MOBILE CHANNEL ESTIMATION ALGORITHM FOR DVB-H COFDM DEMODULATOR - A mobile channel estimation algorithm is disclosed, for use in a DVB-H coded OFDM demodulator. The mobile channel estimation algorithm estimates the mobile channel transfer function, overcoming many of the delay spread limitations without using time filtering and without having to collect many OFDM symbols. Once the channel estimate has been found for each symbol, equalization and inter-carrier-interference cancellation may be carried out relatively easily using known methods. The mobile channel estimation algorithm may be used in DVB-H as well as in other areas of OFDM. | 03-05-2009 |
| 20090086841 | Platform noise mitigation - In one embodiment of the invention, a Fourier transform unit convert a unsynchronized received through multiple antennas to a frequency domain. Also, a spectrum estimation unit determines a power spectrum for the unsynchronized data. A notch filter removes data within a frequency band from additional unsynchronized data based on the power spectrum. A synchronization unit synchronizes the notch filtered data and a noise estimation unit determines a noise covariance matrix between the synchronized data received from multiple antennas. In addition, an equalization unit performs channel equalization on the synchronized data based on the noise covariance matrix. | 04-02-2009 |
| 20090135923 | Mobile channel estimation for DVB-T COFDM demodulator - A channel estimator for use in a DVB-T system is capable of high Doppler performance without incurring restrictive delay spread limitations, in a hardware efficient manner. A first channel impulse response is generated that has ambiguity due to under-sampling in the frequency domain. A filter is then used to filter scattered pilots to generate a mask that is capable of resolving the ambiguities. In at least one approach, a finite impulse response filter is used during the mask generation process to generate a snapshot of the channel frequency response in non-real time. In another approach, an infinite impulse response filter is used during the mask generation process to generate a channel frequency response in real time. | 05-28-2009 |
| 20090167945 | DEVICE, SYSTEM, AND METHOD OF MITIGATING INTERFERENCE TO DIGITAL TELEVISION SIGNALS - Device, system, and method of mitigating interference to digital television signals. For example, an apparatus includes a diversity-based digital television receiver having a filter controller and at least first and second channel paths, wherein the first channel path includes a first Global System for Mobile communication (GSM) reject filter, the second channel path includes a second GSM reject filter, the second channel path is parallel to the first channel path, and the filter controller is to selectively switch an operational state of the first GSM reject filter. | 07-02-2009 |
| 20090268101 | Direct conversion television receiver - A direct conversion television receiver may include a phase de-rotator which substantially undoes the phase rotation of a phase rotator. The phase de-rotator takes the low pass filtered signal and substantially removes the rotation caused by the phase rotator. As a result, it is easier to estimate the phase and gain imbalance and to make a correction for the phase and gain imbalance, via a feedback loop, without the effects of phase rotation. | 10-29-2009 |
| 20100158141 | METHODS AND SYSTEMS TO ESTIMATE CHANNEL FREQUENCY RESPONSE IN MULTI-CARRIER SIGNALS - Methods and systems to determine channel frequency responses corresponding to multi-carrier signals, such as OFDM signals, including to filter or mask noise from channel frequency response estimates in a time domain. | 06-24-2010 |
| 20100166088 | METHOD AND SYSTEM FOR OFDM SYMBOL TIMING RECOVERY - A method and system for OFDM symbol timing recovery is described. A symbol timing recovery module of an OFDM receiver is configured to determine an optimum trigger point for performing a discrete Fourier transform in a manner that minimizes inter-symbol interference. | 07-01-2010 |
| 20100166115 | Phase error detection with conditional probabilities - Apparatuses, systems, and methods that employ conditional probabilities to calculate phase errors are disclosed. For a received signal, the embodiments may develop several phase error estimates relative to each point of a constellation, the number and location of points of the constellation depending on the modulation technique of the received signal. In addition to calculating the phase error estimates, the embodiments may also calculate weights, or probabilities, associated with each of the estimates. The embodiments may use the estimates and the weights to calculate a composite phase error estimate. The composite phase error estimate may be used to correct the received signal and eliminate or reduce the impact of the phase error. | 07-01-2010 |
| 20100169734 | BROADCAST RECEIVER AND METHOD FOR OPTIMIZING A SCALE FACTOR FOR A LOG-LIKELIHOOD MAPPER - Embodiments of a broadcast receiver and method for optimizing a scale factor in a log-likelihood ratio (LLR) mapper are generally described herein. In some embodiments, the broadcast receiver includes an LLR mapper to generate LLRs from demodulated data samples, a low-density parity-check (LDPC) decoder to generate decoded data from the LLRs, and an LLR optimizer to dynamically select a scale factor for the LLR mapper based on a number of iterations for convergence of the LDPC decoder. In some embodiments, the LLR optimizer iteratively revises the scale factor during receipt of broadcast signals until the number of iterations of the iterative decoder is either minimized for convergence or minimized for convergence failures. | 07-01-2010 |
| 20100322326 | Efficient tuning and demodulation techniques - Techniques for the reception and processing of wireless signals are disclosed. For instance, an apparatus may include a first hardware module (e.g., a mixed signal module) and a second hardware module (e.g., a digital signal module). The first hardware module may convert an analog signal corresponding to a received wireless signal into a digital signal having a first sampling rate. In turn, channel filtering may be performed on this digital signal. Following this, the filtered digital signal may be resampled from the first sampling rate to a second sampling rate. At this point, the resampled signal may be transferred across an interface from the first hardware module to the second hardware module. Upon receipt, the second hardware module may correct a sampling rate error in the second sampling rate, and demodulate the digital signal into one or more symbols. | 12-23-2010 |
| 20100330932 | Apparatus and methods for efficient implementation of tuners - Embodiments of systems and methods for the efficient implementation of tuners are generally described herein. Other embodiments may be described and claimed. | 12-30-2010 |
| 20110149171 | Efficient tuning and demodulation techniques - Techniques for the reception and processing of wireless signals are disclosed. For instance, an apparatus may include multiple receiving paths, a content stream generation module, and a distribution module. The multiple receiving paths include a first receiving path that generates a first decoded signal from an input RF signal in accordance with a first tuning setting. The content stream generation module has first and second inputs. Based on decoded signals received at the first and second inputs, the content stream generation module may generate first and second content streams, respectively. In situations where both the first and second content streams correspond to the first tuning setting, the distribution module provides the first decoded signal to both the first and second inputs of the content stream generation module. Also, a control module may remove operational power from any of the plurality of receiving paths that are currently being unused. | 06-23-2011 |
| 20110154148 | SPECTRAL CONTENT BASED DECODING AND FREQUENCY OFFSET ESTIMATION - Methods and systems to identify a codeword associated with samples of a signal from spectral content of the samples, and to estimate a frequency offset from the spectral contents. The samples may correspond to a physical layer header of a data frame. Modulation may be removed from the samples in accordance with each of a plurality of modulation sequences, each sequence associated with a corresponding codeword. Power levels in spectral contents of the modulation-removed samples are examined to identify a peak power level indicative of a match between a modulation sequence and the samples. The corresponding codeword is identified as being associated with the header, and transmission parameters associated with the identified codeword are used to decode a corresponding frame. An estimated frequency offset may be determined from a frequency associated with the peak power level. | 06-23-2011 |
| 20110158334 | PARAMETER AND SCATTERED PILOT BASED SYMBOL TIMING RECOVERY - Methods and systems to resolve the cyclic time ambiguity of a scattered pilot based channel impulse response, including to determine a channel impulse response from a combination of scattered pilots and encoded parameters, such as L1-pre signaling within P2 symbols of a terrestrial digital video broadcast (DVD) in a single frequency network (SFN), and including to re-use a corresponding window time to track the channel impulse response in the absence of encoded parameters. Methods and systems disclosed herein may be implemented with respect to channel acquisition and tracking, including adjusting a Fast Fourier Transform trigger point to reduce inter-symbol interference. | 06-30-2011 |
