摘要:
Techniques and apparatus for controlling the transmit power of an uplink (UL) signal from a user terminal in a wireless communications system in an effort to achieve some target characteristic, such as a target carrier-to-interference (C/I) ratio, at an access point (AP) are provided. In this manner, such a user terminal may help avoid or compensate for imbalances in received radio frequency (RF) power between UL signals received from multiple user terminals by the AP. For example, the transmit power at each user terminal may be controlled in an effort to achieve a target post-processing C/I ratio of 28 dB per spatial stream in an effort to reduce large power imbalances and optimize throughput per user terminal. The user terminal and the AP may compose part of a multiple-input multiple-output (MIMO) communication system utilizing spatial-division multiple access (SDMA) techniques.
摘要:
Certain aspects of the present disclosure generally provide methods and apparatus for enhanced discovery procedures in peer-to-peer (P2P) wireless local area networks (WLANs). With these procedures, discovery duration may be decreased, battery power consumption may be reduced during discovery, provided services may be ascertained during the device discovery phase without performing a separate service discovery phase, and/or the discovery range may be extended in an effort to discover a greater number of devices.
摘要:
Certain aspects of the present disclosure relate to techniques for achieving adaptive channel state information (CSI) feedback rate in multi-user communication systems. A rate by which CSI feedback can be transmitted from each user station of a wireless system to a serving access point may be adjusted based on evolution of a channel between that user station and the access point.
摘要:
Certain aspects of the present disclosure provide techniques and apparatus for generating a unified format of channel state information (CSI) feedback for Very High Throughput (VHT) wireless systems. One example method generally includes generating, at a first apparatus, a frame comprising information relating to SNR if a second apparatus is communicating with the first apparatus using single-user MIMO (SU-MIMO) or multi-user MIMO (MU-MIMO) and transmitting a signal based on the generated frame to the second apparatus. Another example method generally includes generating, at an apparatus, a structure comprising CSI, wherein the CSI includes one of a first matrix with estimates of a channel associated with the apparatus or a second matrix obtained based on singular value decomposition (SVD) of the first matrix and wherein the structure further comprises an indication of which of the first and second matrices is included in the CSI; and transmitting the structure over the channel.
摘要:
Systems, methods, and devices to enable monitoring of wireless networks are described herein. In some aspects, a low power receiver or a receiver operating in a low power mode scans for signals with a moderate or low duty cycle. If a signal identifying a device or user of the receiver, or a signal indicating that there will be a subsequent data communication, is received, a high power receiver or a receiver operating in a high power mode is activated to receive data communications.
摘要:
Systems, devices, and techniques for MIMO (Multiple-In-Multiple-Out) based space-frequency coding can include, in at least some implementations, techniques that include selecting a spatial multiplexing rate M for a transmission of data via two or more antennas, the data comprising N data streams, applying a first mapping to map the N data streams to a first portion of the antennas for a first data tone; and applying a different second mapping to map the N data streams to a different second portion of the antennas for a second data tone.
摘要:
Systems and methods for communicating packets having a plurality of formats are described herein. In some aspects, a signal (SIG) field in the preamble of a packet may indicate whether an extension field, such as an extension SIG field or SIG-B field, is included in the packet. In another aspect, one or more detectors may be used to auto-detect packets formatted as one of at least two different formats based on a short training field (STF) of a received packet. In some aspects, along training field (LTF) in the preamble of a packet may indicate whether the payload is repetition coded.
摘要:
Systems and methods for computing log likelihood ratios in a communication system are described. A demodulated symbol may be received. A set of scalars may be determined based on a modulation order, a signal-to-noise ratio for the symbol, and a bit of the symbol. At least one log likelihood ratio for the bit may be approximated using a piecewise linear process based on the scalars and the symbol.
摘要:
Systems and techniques for rate adaptation in wireless communication systems are described. A described technique includes generating a transmission packet parameter associated with packets transmitted by a device at a first data rate; generating a reception packet parameter associated with packets received by the device; determining a second data rate based on the transmission packet parameter and the reception packet parameter; and transmitting future packets at the second data rate.
摘要:
Systems, methods, and devices for wireless communication. In one aspect, an apparatus for wireless communication is provided. The apparatus includes a receiver configured to receive a wireless signal comprising a packet. At least a portion of the wireless signal is configured to be received over a bandwidth lower than or equal to 1.25 MHz. The packet is formed from at least one orthogonal frequency-division multiplexing (OFDM) symbol comprising thirty-two tones. The thirty-two tones correspond to frequency subcarriers within the bandwidth. The thirty-two tones of the at least one OFDM symbol are allocated as: twenty-four data tones, two pilot tones, five guard tones, and one direct current (DC) tone. The apparatus includes a processor configured to evaluate the wireless signal. The processor includes a transform module configured to convert the at least one OFDM symbol into a frequency domain signal using a thirty-two point mode.