Patent application number | Description | Published |
20080285632 | DECODING OF THE OVERHEAD CHANNELS OF THE GEO SATELLITE REVERSE LINK - A power efficient technique is used to demodulate the coded overhead channels of a GEO satellite uplink. A coherent receiver used in a wireless communication system is able to determine the information conveyed in the overhead channel, by effecting channel estimates from codewords extracted from a pilot signal. A valid set of codewords is established. Pilot symbols are extracted from a pilot signal and a channel estimate is made from the pilot signal. Codewords in the set of valid codewords are correlated and a channel phase ambiguity in the signals is removed and a codeword with the largest correlation is chosen. The chosen codeword is used to create a revised channel estimate. | 11-20-2008 |
20100054371 | Noise Variance Estimation In Wireless Communications For Diversity Combining and Log Likelihood Scaling - The present patent application comprises a method and means for demodulating symbols, comprising converting an OFDM symbol from a time domain to a frequency domain, selecting pilot tones, making a soft decision based on received data, and estimating a channel frequency response. In another example, the method and means further comprises selecting guard tones. In another example, the method and means further comprises generating channel estimates for in-band and band-edge pilot tones. | 03-04-2010 |
20110096853 | Channel estimation in communications - A time averaging filter for channel estimation is described. Different time averaging is used for different taps or tones of a communication system. Two methods are suggested for determining the time-averaging filter for channel estimation for the communication systems without prior knowledge of SNR, channel Doppler and fading statistics. The first method includes a bank of different filters, each tuned for optimality in a certain range of SNR and Doppler. For each tone in the frequency domain (or tap in the time domain), the first method selects a filter among the set of filters that minimizes a certain computed metric. The second method directly computes, at each tone (or tap), the “best” filter in a least-squares sense, using empirically determined second-order statistics. | 04-28-2011 |
20110128866 | REVERSE LINK DATA RATE INDICATION FOR SATELLITE-ENABLED COMMUNICATION SYSTEMS - Reverse link data rate indications in wireless communication systems are defined with low identification overhead. Existence of a pilot signal is leveraged in order to reduce the overhead for identifying and selecting the reverse link data rate. At least two distinguishable pilot signals are defined, in which, based on the particular pilot signal present in the transmitted frame, at least one rate set from the multiple available rate sets can be determined. Reverse rate information in the transmitted frame is then used to identify which specific data rate within the determined rate set is used. Based on the identified data rate, the receiver may then decode the payload data in the transmitted frame. | 06-02-2011 |
20110128867 | FORWARD LINK DATA RATE CONTROL AND RATE INDICATION FOR SATELLITE-ENABLED COMMUNICATIONS SYSTEMS - In a synchronous application to control forward link (FL) data rates in a satellite system, user equipment (UE) repeatedly transmits a quality control measurement (QCM) index during a QCM period. During this QCM period, the data rate cannot change. The associated satellite transmits at a new rate corresponding to the QCM index. The UE knows that it will begin receiving new data at the new rate after a QCM delay. In an asynchronous application, a satellite transmits a rate change signal over a FL rate indication channel (RICH). A UE monitors the FL RICH for this signal. When the signal quality is to be low, the satellite sends only a single bit of the QCM index over a first orthogonal channel. When the signal quality is not low, the satellite transmits each bit of the QCM index in a separate orthogonal channel of the FL RICH. | 06-02-2011 |
20110134823 | SYNCHRONIZED BROADCAST/MULTICAST COMMUNICATION - Synchronized broadcast transmits a same broadcast content using a same waveform from multiple transmitters. Transmitters each apply a same spreading code for broadcast transmissions. In a spread-spectrum communication system having a time division multiplexed forward link, a synchronized broadcast transmission is inserted into a broadcast slot. One embodiment employs an Orthogonal Frequency Divisional Multiplex (OFDM) waveform for the synchronized broadcast. An OFDM receiver is then used to process the received synchronized broadcast transmission. An alternate embodiment implements a broadcast Pseudo-random Noise (PN) code for use by multiple transmitters. An equalizer is then employed to estimate the synchronized broadcast transmission. | 06-09-2011 |
20110134824 | SYNCHRONIZED BROADCAST/MULTICAST COMMUNICATION - Synchronized broadcast transmits a same broadcast content using a same waveform from multiple transmitters. Transmitters each apply a same spreading code for broadcast transmissions. In a spread-spectrum communication system having a time division multiplexed forward link, a synchronized broadcast transmission is inserted into a broadcast slot. One embodiment employs an Orthogonal Frequency Divisional Multiplex (OFDM) waveform for the synchronized broadcast. An OFDM receiver is then used to process the received synchronized broadcast transmission. An alternate embodiment implements a broadcast Pseudo-random Noise (PN) code for use by multiple transmitters. An equalizer is then employed to estimate the synchronized broadcast transmission. | 06-09-2011 |
20110134967 | SYNCHRONIZED BROADCAST/MULTICAST COMMUNICATION - Synchronized broadcast transmits a same broadcast content using a same waveform from multiple transmitters. Transmitters each apply a same spreading code for broadcast transmissions. In a spread-spectrum communication system having a time division multiplexed forward link, a synchronized broadcast transmission is inserted into a broadcast slot. One embodiment employs an Orthogonal Frequency Divisional Multiplex (OFDM) waveform for the synchronized broadcast. An OFDM receiver is then used to process the received synchronized broadcast transmission. An alternate embodiment implements a broadcast Pseudo-random Noise (PN) code for use by multiple transmitters. An equalizer is then employed to estimate the synchronized broadcast transmission. | 06-09-2011 |
20140368321 | ULTRA-WIDEBAND RANGING WAVEFORM - Methods, systems, devices, and apparatuses are described for location tracking in which each tag used to track an asset or person in an indoor environment transmits ranging waveforms used to estimate a location of the tag. Multiple tags may concurrently transmit without interfering with each other by having each tag use a distinct frequency shift for the ranging waveforms. Access points may be deployed throughout the indoor environment as part of a wireless network (e.g., ultra-wideband or UWB network) that tracks the assets. The access points may receive the ranging waveforms transmitted by the tags and may perform measurements based on the ranging waveforms. The measurements may be sent to a tracking management server to estimate the location of the tags. The server may also determine and assign the distinct frequency shifts used by the tags and may modify the assignment when the number of tags being tracked changes. | 12-18-2014 |
20150085834 | TIME DIVISION LONG TERM EVOLUTION (TD-LTE) FRAME STRUCTURE MODIFICATION - A method of wireless communication includes communicating with a base station using an extended special subframe. Communicating with the base station using the extended special subframe may be performed by disabling an uplink pilot time slot and an adjacent uplink subframe. | 03-26-2015 |
20150085840 | TIME DIVISION LONG TERM EVOLUTION (TD-LTE) FRAME STRUCTURE - A method of wireless communication includes communicating with a base station using a special subframe that extends a guard period over an uplink pilot time slot and one or more disabled, adjacent uplink subframes. The method also includes associating a control information subframe with a specific downlink subframe while accounting for both cell radius extension and loss of the one or more disabled, adjacent uplink subframes used to communicate the extended special subframe. | 03-26-2015 |