Patent application number | Description | Published |
20090046772 | METHOD AND APPARATUS FOR CARRIER POWER AND INTERFERENCE-NOISE ESTIMATION IN SPACE DIVISION MULTIPLE ACCESS AND MULTIPLE-INPUT/MULTIPLE-OUTPUT WIRELESS COMMUNICATION SYSTEMS - Estimates of carrier signal power S and interference-noise NI at the output of the equalizer in a wireless communication system is obtained by (i) determining the variance, σ | 02-19-2009 |
20090092203 | ADAPTIVE SELF-QUIETER SUPPRESSION FOR OFDM WIRELESS COMMUNICATION SYSTEMS - Various embodiments to provide cancellation techniques that can be used to address the self-quieter problem are described. For example, a receiver that includes a tone selector and a self-quieter suppressor is provided. The tone selector ( | 04-09-2009 |
20090135949 | DIGITL PRE-DISTORTION FOR OTHOGONAL FREQUENCY DIVISION MULTIPLEXING (OFDM)SIGNALS | 05-28-2009 |
20090161527 | A METHOD FOR UPLINK COLLABORATIVE SDMA USER PAIRING IN WIMAX - A method, system, and communication network for grouping a pair of independent information signals on the same time-frequency orthogonal frequency division multiplexing (OFDM) resources for uplink (UL) collaborative SDMA, in a wireless communication system. An uplink scheduling (ULS) utility employs an estimated channel gain associated with the transmission path(s) of each user to create a pairing metric that effectively computes the correlation between each pair of independent information signals on a specific sub-carrier frequency channel. Pairs of information signals are considered as possible groupings when the values of the corresponding pairing metrics are less than a threshold maximum value. An optimal selection of final pairings is based on the relative values of the pairing metric(s) and other priority conditions which may include quality of service requirements. The ULS utility enables the UL scheduler to pair information signals with a clear spatial distinction and minimal correlation. | 06-25-2009 |
20090268709 | TIME AND FREQUENCY CORRECTION FOR AN ACCESS POINT IN AN OFDMA COMMUNICATION SYSTEM - An apparatus and method for method for timing and frequency error correction in an access point. The method includes a first step ( | 10-29-2009 |
20090268710 | UPLINK SYNCHRONIZATION WITHOUT PERIODIC RANGING IN A COMMUNICATION SYSTEM - An apparatus and method for uplink synchronization without periodic ranging in a communication system includes a first step ( | 10-29-2009 |
20100067363 | METHOD AND SYSTEM FOR RADIO FREQUENCY (RF) GROUP DELAY COMPENSATION IN A BROADCAST SYSTEM - A radio device operable to compensate for a large RF filter group delay variation is provided. The radio device includes a receiving unit operable to receive an OFDM signal that comprises pilot subcarrier signals and data subcarrier signals. The radio device further includes a group delay (GD) compensator, operable in frequency domain, and configured to perform phase rotation to correct a group delay individually on tones of an OFDM symbol. The phase rotation is calculated as a function of the phase shifts of the received pilot subcarrier signals and subcarrier index. | 03-18-2010 |
20100296438 | UP-LINK SDMA RECEIVER FOR WiMAX - A method, a system and a receiver device provide timing and frequency correction in a spatial division multiple access (SDMA) system. A timing and frequency correction (TFC) logic/utility obtains a timing error estimate by using pilot symbols on a slot of six tiles. The TFC logic estimates the timing error based on pilot phase differences between unique pairs of tiles when the frequency separation of the tiles is less than a threshold value. When none of the unique pairs of tiles satisfies the threshold value, the TFC logic estimates timing error based on an exhaustive search for each candidate phase error value. The TFC logic performs timing error correction via a timing error estimate based on pilots from the symbols received on each antenna. The TFC logic performs inexplicit frequency error correction according to phase differences based on relative symbol indices. | 11-25-2010 |
20110216734 | SYNCHRONIZATION IN AN UPLINK SPATIAL DIVISION MULTIPLE ACCESS MODE OF A WiMAX WIRELESS COMMUNICATION SYSTEM - An apparatus and method for synchronization in an uplink spatial division multiple access (UL SDMA) mode of a WiMAX wireless communication system includes a first step ( | 09-08-2011 |
20140169280 | Timing Error Estimate Of UL Synchronization - The specification and drawings present a new method, apparatus and software related product (e.g., a computer readable memory) for a timing offset/error estimate (TOE) method, e.g., for a LTE UL receiver. This may especially beneficial for the MU-MIMO and/or CoMP with MAAS applications, where the conventional methods do not work properly due to a strong interference among users (UEs) sharing the same radio resource. Two approaches (separately or in combination) may be used to improve TOE quality. First, the timing offset/error may be calculated using phase difference for pilot pairs with non-adjacent pilots/carriers having a larger separation between subcarriers than for pilot pairs with adjacent subcarriers. Second, a modified pilot sequence for timing offset estimate may be created using sliding an averaging window. This can effectively remove interference which is critical for the MU-MIMO and CoMP applications. | 06-19-2014 |