Abstract:
An access point determines the buffered data for each station of a plurality of stations in a BSS and groups the stations with similar station characteristics. The transmission time to the stations in a group can be apportioned. The groups can be ordered based on station characteristics and a transmission history. A sounding for a group can be performed based on the order. The MU-MIMO transmission for the group can be performed until a first condition is met. If the first condition is met, then the sounding and the MU-MIMO transmission for a next group can be performed, according to the order, until a second condition is met. The first condition can include an apportioned transmission time having expired and/or the buffers for the group being flushed. The second condition can include new data having been buffered by the AP and/or all buffered data having been transmitted.
Abstract:
Methods, systems, and devices for wireless communication are described. A ranging message procedure may employ protection by modifying a cyclic prefix of the ranging message to prevent an attacking device from transmitting a time-advanced copy of the cyclic prefix during symbol of the copied signal. For example, the modified cyclic prefix may include pseudo random training sequences or a set of zero-value symbols. The receiving device may determine a channel estimation technique that accounts for the modified cyclic prefix. The wireless devices performing the ranging measurement process may determine a modulation and coding scheme (MCS) for the ranging message. The wireless devices may negotiate an MCS value and cyclic prefix configuration for the ranging measurement process. In some examples, the ranging message be encoded by applying a sequence of phase rotations or amplitude variations to the base sequence used to generate the sounding training signal.
Abstract:
Methods, systems, and devices for wireless communication are described. Wireless devices may use multiple transmission modes to enable association and authentication procedures for wireless devices with different capabilities. For example, a station may receive, in response to a broadcast probe request, a probe response frame formatted according to a first transmission mode. The station may then transmit a second probe request frame formatted according to the first transmission mode. At some later time, the station may identify that the second probe request frame was not received by the wireless device, and may transmit another probe request frame formatted according to an extended range transmission mode. The station may then establish a connection with the wireless device by completing an association and authentication procedure, and proceed to transmit data or control frames formatted according to the extended range transmission mode.
Abstract:
A method of adjusting single-stream transmissions by a wireless device based on channel state information (CSI). The wireless device generates a sounding packet formatted for transmission via multiple spatial streams, and transmits the sounding packet to a receiving device via a single one of the multiple spatial streams. For example, the wireless device may be a single-antenna device. The wireless device further receives channel state information (CSI) from the receiving device based at least in part on the sounding packet. The wireless device then adjusts one or more characteristics of single-stream transmissions to the receiving device based at least in part on the received CSI.
Abstract:
Methods, systems, and devices are described for power conservation in a wireless communications system. In embodiments, power conservation may be achieved by adaptively controlling power modes of a wireless communication device, and implementing lower power modes with various modes of the device. According to one aspect, the mode of the device may be a beacon monitoring mode or a delivery traffic indication message (DTIM) mode. In such a mode, the device may receive a portion of a beacon in a first power mode. The device may transition to a second, different (e.g., higher) power mode using information contained in the received portion of the beacon as guidance.
Abstract:
Methods, systems, and devices are described for power conservation in a wireless communications system. In embodiments, power conservation may be achieved by adaptively controlling power modes of a wireless communication device, using a modulation and coding scheme (MCS) value as a factor for guidance. According to one aspect, the device may be in a reception mode. While in a first power mode, the device may receive control information for incoming data that is being transmitted via a transmission frame. The control information may be located in a first portion of the frame with the data following in a second portion of the frame. The control information may include or otherwise indicate an MCS value corresponding to the MCS applied to the incoming data. Based on the MCS value, the device may be adaptively switched to a second power mode for receiving the incoming data.
Abstract:
A power amplifier system including a composite digital predistorter (DPD) ensuring optimized linearity for the power amplifier is described. In this system, a digital-to-analog converter (DAC), an analog filter, a first mixer, and the power amplifier are serially coupled to the composite DPD. A second mixer, a receive gain block, and an analog-to-digital converter (ADC) are serially coupled to the output of the power amplifier. A DPD training component is coupled between the inputs of the composite DPD and the ADC. The composite DPD includes a memory-based DPD, e.g., a memory polynomial (MP) DPD, a memoryless-linearizing DPD, e.g., a look-up table (LUT) DPD, and two multiplexers.
Abstract:
Method of performing dual-mode rate control for an access point in a wireless communication system includes a single-user mode of operation and multi-user mode of operation. In the single-user mode, a basic rate for a station is determined based on channel conditions. In the multi-user mode, a rate for a plurality of stations is determined using tracking. The tracking includes performing a sounding for the plurality of stations. An initial multi-user current rate is then set equal to a function of a number of users and the basic rate. A transmission is sent to the plurality of stations using the current rate. A packet error rate (PER) is detected during transmission to the plurality of stations. The current rate is adjusted based on the PER. After rate adjustment, either sounding is triggered or the method returns to sending a transmission using the current rate.
Abstract:
A method of providing rate adaptation in a multi-user wireless communication system including single-user beamforming (SU-BF) and multi-user multiple-input multiple-output (MU-MIMO) is described. In this method, a master rate, which is a modulation and coding scheme (MCS) for the SU-BF, is determined. An MCS for each transmit mode is derived from the master rate using a rate mapping. Using the results from the mapping, the master rate, instead of the MCS for each transmit mode, is tracked. In one embodiment, a mapping calibration is periodically performed.
Abstract:
A TOA positioning system can be implemented to improve location estimation of a wireless network device. A first subset of a plurality of reference wireless network devices for determining potential locations of the wireless network device and a second subset of the plurality of reference wireless network devices for determining an estimated location of the wireless network device can be selected. The first and the second subsets can be selected based on a plurality of distance measurements and an average distance and associated with each of the plurality of reference wireless network devices. The potential locations of the wireless network device can be determined based on the first subset of the plurality of reference wireless network devices. The estimated location of the wireless network device can be determined from the potential locations of the wireless network device based on the second subset of the plurality of reference wireless network devices.