Apple Inc.

Arraycomm, Inc.

Xiaoming Yu

Peter M Agboh

Vusthla Sunil Reddy

Alejandro J Marquez

Shang-Te Yang

Indranil S Sen

Athanasios Agamamnon Kasapi

Manjit S Walia

Lei Li

Adam Bruce Kerr

Lars Persson

Lars Johan Persson

Ali Pourghorban Saghati

Pradeep K Marri

Xiangzhong Zeng

Methods and apparatuses are presented to locate a wireless communication device. A target device may be out of range of a source device for normal ranging communications according to a first radio access technology (RAT), such as ultra wideband (UWB) communications. A source device may therefore modify communications according to the first RAT, to increase the transmit power, while removing the data payload. The target device may utilize the signal strength and angle of arrival of the modified communications to guide the user to move toward the source device, e.g., until the target device is within range to perform normal ranging communications. A second RAT, such as Bluetooth, may be used to communicate between the two devices while the target device is out of range of the first RAT. For example, the target device may use the second RAT to communicate to the source device to start/stop transmitting modified communications.

Ultra wideband range extension

Some embodiments include a system, method, and computer program product for managing the Ultra Wideband (UWB) systems, especially when the UWB system is collocated with another wireless system (e.g., WiFi) to transmit and/or receive UWB signals with an occupied bandwidth (OBW) that satisfies a UWB OBW standard (e.g., a UWB OBW&#x3e;=500 MHz.) In some embodiments a TailBit signal (e.g., a periodic signal at a selected frequency) is added to a UWB packet to generate frequency components at the selected frequency that enables the power spectrum of the TailBit UWB signal to satisfy the UWB OBW standard. In some embodiments an altered code sequence is used to generate an altered spread signal, where the altered code sequence reduces or removes a frequency component peak near DC frequency of the power spectrum of an altered UWB signal, resulting in altered UWB OBW that satisfies the UWB OBW standard.

Apparatus and method for managing ultra wideband (UWB) occupied bandwidths

Methods and apparatuses are presented to reduce multiuser interference resulting from two or more overlapping ultra wideband (UWB) transmissions by randomizing the start time of packets and/or bursts within the packets. A random offset time may be generated for a packet, and transmission of the packet may be arbitrarily delayed by that random offset time, relative to an earlier time at which the packet is prepared for transmission. A random offset time may be generated for a pulse burst within a symbol of a packet, and transmission of the burst may be delayed by that random offset time, relative to a nominal transmission window within the symbol. The burst may therefore occupy a portion of a guard period following the nominal transmission window. Either procedure, or both procedures, may be used to reduce multiuser interference between two concurrently transmitted packets by randomizing overlap occurring between the bursts.

Methods and apparatus for ultra wideband multiuser interference reduction

An embodiment of the invention provides a method for effecting switchback on a spatial division multiple access (SDMA) PHS channel. A communication signal is broadcast over each of one or more SDMA channels of a multi-access channel to one or more corresponding user terminals. A set of transmit spatial weights is determined for a synchronization burst to a user terminal attempting to reestablish communication over an SDMA channel of the multi-access channel. The set of transmit spatial weights is determined such that interference caused by one or more communication signals to the synchronization burst is reduced.

Methods for reliable user switchback on a PHS spatial division multiple access channel

Embodiments of the invention provide various methods for detecting a spatial division multiple access (SDMA) channel swap. A first SDMA communication channel is assigned to a first user terminal that initially transmits its signal over the first SDMA communication channel. A second SDMA communication channel is assigned to a second user terminal that initially transmits its signal over the second SDMA communication channel. The first user terminal's signal and the second user terminal's signal are analyzed to determine that the first user terminal is transmitting its signal over the second SDMA communication channel and the second user terminal is transmitting its signal over the first SDMA communication channel.

Detection and correction of channel swap in spatial division multiple access systems

A receiving device receives a stream of information and appended thereto a cyclic redundancy check (CRC) value for the information stream. A new CRC value is computed for the information stream and compared to the CRC value. If the CRC value and the new CRC value differ, then a segment of the information stream is altered, and a pointer based on the altered information stream is obtained. The pointer points to a table from which a value is obtained that is used in revising the new CRC value. The CRC value is compared to the new CRC value as revised, and if they still differ, again the information stream is altered, the new CRC value revised in connection therewith, and the CRC value again compared to the new CRC as revised. This process repeats until such time as any data integrity error in the information stream is corrected, or some other appropriate action is taken to end the process.

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Cupertino, CA, United States of America

Xiaoming Yu