Patent application number | Description | Published |
20090034592 | Crosstalk Cancellation in Digital Subscriber Line Communications - A digital subscriber line (DSL) modem that has a canceller digital filter for cancelling crosstalk and RF interference in a received DSL signal is disclosed. The modem includes common-mode sense circuitry and also differential-mode sense circuitry. Samples of the common-mode signal are acquired during a “quiet” period of initialization of the DSL modem, and samples of the differential-mode signal are acquired during live transmission of a DSL signal. An estimate of an autocorrelation function is obtained from the common-mode samples, and a cross-correlation of the common-mode samples and differential-mode samples is also estimated. Digital filter coefficients are derived from these estimates, based on the assumption that the common-mode samples acquired during the “quiet” phase represent crosstalk and RF interference present during differential-mode communications. The digital filter coefficients can also be updated during showtime of the DSL link, using an expanded number of samples of the common-mode and differential-mode signals. | 02-05-2009 |
20100067596 | METHODS AND SYSTEMS FOR HYBRID MIMO DECODING - Certain embodiments of the present disclosure allow a receiver to utilize both a minimum mean square error (MMSE) detection algorithm and a maximum likelihood (ML) detection algorithm. The receiver may control, based on various conditions, a mode selection signal to select between output generated with the MMSE detection algorithm and the ML detection algorithm. By sharing logical components, certain embodiments may allow a receiver to implement both ML and MMSE detection algorithms with minimal computational overhead when compared to implementing a single one of the decoding algorithms. | 03-18-2010 |
20100067600 | MMSE MIMO DECODER USING QR DECOMPOSITION - Aspects of the disclosure provide unbiased channel equalization applied in a MIMO OFDM system with spatial multiplexing. According to certain embodiments, a MMSE receiver can be implemented with the QR decomposition (QRMMSE detection) instead of direct inversion of channel matrix by exploiting an augmented channel matrix. A simple and efficient bias removal technique is presented herein, whereby unbiased QRMMSE equalization may provide identical detection accuracy as a conventional unbiased MMSE approach. For certain embodiments, multiple access interference may be further reduced if the VBLAST version of the unbiased QRMMSE detection is applied. | 03-18-2010 |
20100167653 | METHODS AND SYSTEMS FOR CO-CHANNEL INTERFERENCE CANCELLATION IN WIRELESS NETWORKS - Certain embodiments of the present disclosure relate to methods for mitigating interference of signals transmitted to a mobile station (MS) from a plurality of neighboring base stations. By applying a proposed spatio-frequency modulation (SFM) technique at a serving base station (BS) and at each interfering BS, a co-channel interference (CCI) from interfering base stations can be efficiently mitigated at the MS and signal transmitted from the serving BS can be more accurately decoded. | 07-01-2010 |
20120281553 | IDLE MODE RECEIVE ANTENNA DIVERSITY SYSTEM - Electronic devices may be provided that contain wireless communications circuitry. The wireless communications circuitry may include radio-frequency transceiver circuitry coupled to multiple antennas. An electronic device may alternate between a sleep mode and a wake mode. During wake mode, the electronic device may monitor a paging channel in a wireless network for incoming paging signals. The device may use either a single antenna mode or a multiple antenna mode such as a dual antenna mode in monitoring the paging channel. In the single antenna mode, a single active antenna is used to receive paging signals. In the dual antenna mode two antennas are simultaneously used to receive paging signals. The device may choose which antenna mode to use based on signal quality measurements and history information on successfully received paging signals. | 11-08-2012 |
20120282982 | ELECTRONIC DEVICE WITH IDLE MODE ANTENNA SWITCHING - Electronic devices may be provided that contain wireless communication circuitry. The wireless communication circuitry may include radio-frequency transceiver circuitry coupled to multiple antennas. An electronic device may alternate between a sleep mode and a wake mode. During wake mode, the electronic device may monitor a paging channel in a wireless network for incoming paging signals. The device may use a selected one of the multiple antennas in monitoring the paging channel. If received signal quality is satisfactory, the device may maintain use of the selected one of the multiple antennas for subsequent wake period monitoring of the paging channel. If received signal quality falls below a threshold or is otherwise indicated to not be satisfactory, the device may switch to use of a different one of the multiple antennas in monitoring the paging channel. Other criteria may also be used in controlling the switching between antennas for paging channel monitoring. | 11-08-2012 |
20130035103 | METHODS FOR TRANSMIT ANTENNA SWITCHING DURING UPLINK ACCESS PROBING - Electronic devices may be provided that contain wireless communication circuitry. The wireless communication circuitry may include radio-frequency transceiver circuitry coupled to first and second antennas. An electronic device may send network access probe signals to a base station in a wireless network. If the base station responds with a corresponding acknowledgement, the electronic device and base station may establish a wireless communication link such as a cellular telephone link. In response to failure to receive the acknowledgement signal from the base station, the electronic device may increase the transmit power of a successive network access probe signal. The electronic device may switch between use of the first and second antennas when transmitting the network access probe signals. The electronic device may alternate between the first and second antennas or may use other antenna usage patterns. | 02-07-2013 |
20130225094 | METHODS AND APPARATUS FOR INTELLIGENT RECEIVER OPERATION - Methods and apparatus for adaptively adjusting receiver operation for e.g., power optimization. In one embodiment, operation during diversity operation is adaptively adjusted. Diversity techniques consume significantly more power than non-diversity operation. However, the performance gain from receiver diversity is not always predictable. Consequently, in one embodiment, a device evaluates the overall performance gain contributed by diversity operation and, where the performance gain is insignificant or inadequate, the device disables diversity operation. In one implementation, the device can operate in a static single antenna mode, a dynamic single antenna mode and a dynamic multiple antenna mode. | 08-29-2013 |
20130260758 | APPARATUS AND METHODS FOR SYNCHRONIZATION RECOVERY IN A HYBRID NETWORK - Methods and apparatus for synchronizing operational state during hybrid network operation. In one embodiment, the various access technologies that makeup the hybrid network not fully synchronized. Thus, a wireless device operating in a mixed mode must be capable of managing synchronization across multiple access technologies. The wireless device is configured to estimate an expected “tune-away” period when disengaging with a one access technology to address events (for example, link maintenance, calls, data, and the like) or perform monitoring on a second access technology. The estimate is then used by the device to adjust its operational parameters on the technology from which it is tuning away. This ensures smooth switching away from and back to the various network technologies. | 10-03-2013 |
20130288624 | METHODS AND APPARATUS FOR ADAPTIVE RECEIVER DIVERSITY IN A WIRELESS NETWORK - Apparatus and methods for implementing “intelligent” receive diversity management in e.g., a mobile device. In one implementation, the mobile device includes an LTE-enabled UE, and the intelligent diversity management includes selectively disabling receive diversity (RxD) in that device upon meeting a plurality of criteria including (i) a capacity criterion, and (ii) a connectivity criterion. In one variant, the capacity criterion includes ensuring that an achievable data rate associated with a single Rx (receive) chain is comparable to that with RxD. | 10-31-2013 |
20150079917 | Methods and Apparatus for Adaptive Receiver Diversity in a Wireless Network - Apparatus and methods for implementing “intelligent” receive diversity management in e.g., a mobile device. In one implementation, the mobile device includes an LTE-enabled UE, and the intelligent diversity management includes selectively disabling receive diversity (RxD) in that device upon meeting a plurality of criteria including (i) a capacity criterion, and (ii) a connectivity criterion. In one variant, the capacity criterion includes ensuring that an achievable data rate associated with a single Rx (receive) chain is comparable to that with RxD. | 03-19-2015 |