Qualcomm Incorporated

Petru Cristian Budianu

Alexei Yurievitch Gorokhov

David Jonathan Julian

Dhananjay Ashok Gore

Amal Ekbal

Ravi Palanki

Jun Shi

Siddhartha Mallik

Yann Barbotin

Tao Luo

Xiaoxia Zhang

Jing X Sun

Yongbin Wei

Durga Prasad Malladi

Taesang Yoo

Arumugam Chendamarai Kannan

Aamod Dinkar Khandekar

Raghu Narayan Challa

Ashok Mantravadi

Gene Wesley Marsh

Jamie Menjay Lin

Arunava Chaudhuri

Francesco Negro

Hermanth Sampath

Siddartha Mallik

Nagabhushana Sindhushayana Bhushan

Channel feedback reporting for non-orthogonal wireless communication systems employing frequency selective channels. A plurality of channel feedback matrices corresponding to a plurality of sub-carriers of a sub-band for a non-orthogonal channel may be determined by a UE, and one or more effective channel feedback matrices for the sub-band may be determined based on the plurality of channel feedback matrices. Each of the one or more effective channel feedback matrices may be associated with corresponding sets of transmission strategies, where each of the corresponding sets of transmission strategies include one or more transmission strategies of a plurality of transmission strategies for the non-orthogonal channel. Channel feedback information representing the one or more effective channel feedback matrices may be reported to a base station, which may estimate channel quality for the plurality of transmission strategies based at least in part on the channel feedback information, for downlink transmissions to UEs over the non-orthogonal channel.

Channel feedback design for frequency selective channels

Dynamic adjustment of antenna selection period at a wireless communication device or user equipment having two or more antennas. The described approaches consider an antenna selection performance metric. The antenna selection performance metric may include both measurement overhead (capacity loss due to measurements) and antenna switching capacity gain (gain in capacity through switching antenna subsets). The antenna selection performance metric may further include an estimate of UE speed or an antenna selection change rate. The antenna selection period may be adjusted by increasing or decreasing the antenna selection period based on the antenna selection performance metric. Antenna selection may be enabled or disabled based on the antenna selection performance metric.

Antenna selection adjustment

System and method are disclosed for synchronization of a transmitting device and a receiving device that communicate with each other via pulse modulation. The synchronization technique entails the transmitting device sending one or more quasi-periodic pulse sequences to the receiving device. A quasi-periodic pulse sequence is based on a substantially periodic pulse sequence, and may include some non-periodic pulses or not include some periodic pulses. The transmitting device may transmit frames each including a preamble that comprises one or more quasi-periodic pulse sequences, and a data payload that may comprise data. The receiving device receives the signal, generates samples of the signal, and detects the quasi-periodic pulse sequences in the received signal by analyzing samples based on a sample associated with a pulse and the period associated with the substantially periodic pulse sequence. The receiving device is further able to detect frames based on the detection of the sequence, and extract data therefrom.

System and method for transmitting and receiving signal with quasi-periodic pulse sequence

Communication techniques enable efficient communication to an UE (User Equipment) that is subject to a dominant interference signal that is transmitted by a different base station. Disclosed interference cancellation techniques, both UE-centric and network-centric, are suitable to this situation. These techniques are particularly advantageous when undesirable or difficult to introduce changes in the physical (PHY) and medium access control (MAC) layers at the existing base stations. UE-centric framework refers to an approach largely implemented by UEs to include pico or femto cells. Network-centric framework closed-loop coordination between base stations and UEs mitigate interference thereby improving network performance. In particular, an interfering base-station can help a 'victim' UE by adjusting downlink pilot and control power and to adjust traffic data rates responsive to information that the 'victim' UEs provide, including information about the interfering link and performance of the cancellation itself sent over the air or using the backhaul.

Inter-cell interference cancellation framework

Certain aspects of the present disclosure relate to a method for quantizing an analog received signal in a low-power body area network (LP-BAN) by using a limited number of quantization bits, while information of the received signal is preserved for accurate signal reconstruction. The quantized signal can be equalized in such a way to generate an output equalized signal based on the periodic-sinc function, which is suitable for a subsequent Finite Rate of Innovation (FRI) processing. The noisy equalized signal can be further processed by applying improved (i.e., faster) Cadzow denoising algorithm as a part of the FRI processing.

Finite rate of innovation (FRI) techniques for low power body area network (LP-BAN) communications

In a signal-based gain control scheme, one or more gain levels used for processing signals are selected based on characteristics of previously received signals. For example, different gain levels may be used to receive sets of signals whereupon certain characteristics of the received sets of signals are determined. One or more gain levels are then selected based on these characteristics whereby another signal is processed based on the selected gain level(s). In some aspects, the signal-based gain control scheme may be employed to facilitate two-way ranging operations between two devices. For example, leading edge detection may involve determining a characteristic of a received signal, determining a threshold based on the characteristic, and identifying a leading edge associated with the received signal based on the threshold. In some aspects, the signal-based gain control scheme may be employed in an ultra-low power pulse-based communication system (e.g., in ultra-wideband communication devices).

Signal based gain control

In a two-way ranging scheme where a first apparatus (e.g., device) determines a distance to a second apparatus (e.g., device), specified packets are sent between these apparatuses at specified times to facilitate the determination of the distance. In some aspects, these packets may be defined and/or sent in a manner that enables the apparatuses to detect a leading edge of a received packet with a high degree of accuracy. For example, an apparatus may transmit a packet a defined period of time after transmitting or receiving another packet. In addition, a packet may comprise a defined symbol sequence that is used by an apparatus that receives the packet to identify a leading edge of the packet.

Two-way ranging messaging scheme

A leading edge associated with a received signal is detected to provide, for example, time of arrival information for a ranging algorithm. In some aspects, a method of leading edge detection involves sampling a received signal, generating a drift compensated signal based on the samples, reconstructing the received signal based on the drift compensated signal, and identifying a leading edge associated with the received signal based on the reconstructed signal.

Leading edge detection

Signal characteristic-based leading edge detection

Various aspects of an approach for acquiring sequences such as balanced Hamming weight preamble sequences are described herein. The approach provides for the acquisition of preamble sequences base on energy accumulation. The approach includes creating a plurality of synchronization hypotheses, with each hypothesis being created based on energies sampled at a first location and a second location in a plurality of locations associated with a sequence of transmitted symbols; calculating a plurality of metrics based on the plurality of synchronization hypotheses, wherein each metric is associated with a hypothesis; selecting, as a candidate, one hypothesis from the plurality of synchronization hypotheses including a maximum associated metric. The approach may further include determining a boundary in the sequence of transmitted symbols based on a correlation property of the sequence of transmitted symbols. The second location includes a predetermined offset from the first location configured to provide enhanced interference immunity.

Method and apparatus for efficient acquisition of preambles with enhanced interference mitigation

Systems and methodologies are described that facilitate mitigation of interference through uplink scheduling in a wireless communication environment. Access points can assign multiple terminals to a single tile or segment of shared resource (e.g., a time frequency region) to maximize the number of terminals supported. However, combinations of certain types of terminals can cause a significant increase in interference. In particular, allocating multiple terminals having a relatively high velocity (e.g., terminals located in moving vehicles) to a single tile can cause an unacceptable increase in interference. To mitigate interference, high velocity terminals can be identified. Once identified, terminals can be allocated to the available tiles based at least in part upon avoiding combinations that result in a significant increase in interference.

Uplink scheduling for fairness in channel estimation performance

System and method for transmtting and receiving signal with quasi-periodic pulse sequence

Techniques for transmitting pilot and for processing received pilot to obtain channel and interference estimates are described. A terminal may generate pilot symbols for a first cluster in a time frequency block based on a first sequence and may generate pilot symbols for a second cluster in the time frequency block based on a second sequence. The first and second sequences may include common elements arranged in different orders and may be considered as different versions of a single sequence. The terminal may transmit the pilot symbols in their respective clusters. A base station may obtain received pilot symbols from multiple clusters in the time frequency block. The base station may form each of multiple basis vectors with multiple versions of the sequence assigned to the terminal and may process the received pilot symbols with the multiple basis vectors to obtain a channel estimate for the terminal.

Pilot design for improved channel and interference estimation

Within a receiver, a channel estimation mechanism involves a hardware interpolator. In a first mode, narrowband pilot values are analyzed to generate channel parameters that are supplied to the interpolator such that the interpolator generates channel estimate values. The channel estimate values are used to demodulate a tile of a frame. In a second mode, broadband pilot values are supplied to an IFFT, thereby generating time domain values. After time domain processing, an FFT is employed to generate intermediate channel estimate values. These intermediate values are analyzed to determine channel parameters, which in turn are supplied to the hardware interpolator so that the interpolator generates a larger number of channel estimate values. After phase adjustment, the channel estimate values are used in demodulation. Use of the interpolator in the broadband mode allows the FFT employed to be of a smaller order, and to consume less power and/or processing resources.

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San Diego, CA, United States of America

Petru Cristian Budianu