Abstract: Dedicated pilot signals are transmitted from a transmitting device to a receiving device through a multicarrier MIMO channel in addition to data signals and common pilot signals. The dedicated pilot signals may be used by the receiving device to validate whether a predetermined beamforming matrix (i.e., a beamforming matrix identified by the receiving device) was used by the transmitting device to precode the transmitted data. If a different beamforming matrix was used for the preceding, the receiving device may use this matrix to demodulate the received data.

Abstract: An integrated balun includes a low pass filter and a high pass filter that are formed on a semiconductor chip using tunable reactive elements. The outputs of the low pass filter and the high pass filter are tied together to form the single ended output of the balun. The inputs of the low pass filter and the high pass filter form the differential inputs of the balun. The low pass filter and the high pass filter each include a number of tunable networks for achieving the tunable reactive elements. Each tunable network includes at least one switching transistor and at least one fixed value reactive elements. In at least one embodiment, dynamic biasing circuitry may be provided to improve the linearity and reduce the insertion loss of the balun.

Abstract: A low density parity check (LDPC) code is used within a wireless apparatus to perform forward error correction (FEC) coding. In at least embodiment of the invention, a (2000, 1600) bit-length LDPC code is used.

Abstract: An integrated, multi-band radio frequency (RF) filter is capable of modifying a filter response thereof in response to control information. Switching elements within the filter can be changed between on and off conditions to modify the filter response. In one implementation, the integrated, multi-band filter is integrated on a front end module chip to be used within a multi-radio wireless device. In at least one embodiment, linearity enhancement circuitry is provided within a multi-band filter to improve linearity and reduce insertion loss.

Abstract: Techniques are disclosed for achieving efficient paging in a wireless network. In at least one embodiment, paging is performed in a manner that achieves a balance between paging latency and paging signaling overhead.

Abstract: Techniques are presented for improving packet detection within a wireless device in the presence of platform noise. In some embodiments, packet detection is carried out by first performing a correlation operation using a signal at an input of a wireless receiver. The result of the correlation may then be compared to a threshold value in order to make a packet arrival decision. The threshold value may be varied during device operation in a manner that enhances packet detection performance.

Abstract: The size of a block acknowledgement (BA) window used during a BA transaction is varied during the transaction based on one or more parameters that are related to a present channel condition between an originator device and a recipient device.

Abstract: A wireless silencing device transmits a wireless silence signal in or near a region where extraneous sound is undesired. Wireless devices in receipt of the wireless silence signal may use the signal to determine whether to enable an auto silence mode of operation.

Abstract: Multiple wireless user devices act cooperatively to communicate with a remote destination node through a MIMO channel. In at least one embodiment, a cooperative cluster of user devices is formed that makes use of vertical coding techniques to achieve enhanced communication performance.

Abstract: Antenna selection is performed in a multicarrier communication system based on antenna scores. In at least one embodiment, an antenna score is calculated for an antenna by determining grades for individual carriers associated with the antenna based on corresponding signal magnitude related parameters and then combining the grades in a predetermined fashion.

Abstract: Code shortening techniques are used to achieve a variety of code lengths and code rates for Euclidean geometry low density parity check (EG-LDPC) codes.

Abstract: In a multicarrier communication network, specific subcarriers are dedicated for use in carrying burst descriptor information. A subscriber station in the network may monitor the dedicated subcarriers to determine when a burst involving the station is to occur. By using dedicated subcarriers for burst information, scheduling decisions can be made closer in time to the actual bursts.

Abstract: A wireless user device includes functionality for detecting and collecting information about network hotspots in a surrounding environment before an operating system is loaded. In this manner, a mobile user can check for wireless network availability without having to first complete a lengthy boot sequence.

Abstract: A multicarrier base station communicates with subscriber stations of different bandwidth profiles by allocating time slots in downlink and uplink frames and subcarriers of a single multicarrier communication channel to various bandwidth subchannels.

Abstract: In a communication system using closed loop multiple input/multiple output MIMO, beam forming information may be fed back from a receiver to a transmitter sequentially over a number of frames. The beam forming matrices that are fed back may be quantized.

Abstract: Spatial power allocation and bit loading are performed deterministically for a closed loop MIMO system.

Abstract: A flexible power amplifier can be adapted during operation for use in connection with two or more different wireless standards. In at least one embodiment, adaptations to power transistor size, RF bias current, and matching are made when a corresponding multi-standard wireless device changes the wireless standard under which it is currently operating.

Abstract: A power amplifier pre-distortion calibration technique transmits two packets at different power levels for use in the calibration. As each packet is transmitted, it is received by the same device through a loop back path. The two received packets are then processed to develop the information needed to perform digital pre-distortion.

Abstract: Dynamic biasing techniques are used to enhance both linearity and efficiency within a transistor power amplifier. In at least one embodiment, as the power level being processed by a transistor increases toward a saturation point, a transistor is moved from class B or class AB operation toward class A operation. This increases the linearity of operation (because class A operation is typically highly linear) without a corresponding decrease in efficiency (because efficiency typically peaks near saturation). Similarly, as the power level decreases from the saturation point, the transistor is moved from class A or class AB operation toward class B operation. This increases the efficiency (because class B operation is more efficient than class A or AB), while having little effect on linearity (because operation is moving away from saturation).

Abstract: A discrete time filter achieves gain by sampling a signal using capacitors arranged in a one configuration and then changing the capacitors to a series configuration to develop a filter output voltage. In at least one embodiment, a variable gain filter is achieved by varying the number of capacitors that are active in the filter.