Abstract: Systems and methods are disclosed that may detect data transmitted using MIMO communications. MIMO signals may be received via a wireless channel. Channel conditions may be estimated for the wireless channel based at least in part on the received MIMO signals. Each tone of the received MIMO signals may then be processed according to either a first receiver algorithm or a second receiver algorithm based at least in part on the estimated channel conditions, where the second receiver algorithm has a greater complexity and a greater accuracy than the first receiver algorithm.

Abstract: Methods, systems, and devices for wireless communication are described. In some systems (e.g., Wi-Fi systems), a transmitting device such as an access point (AP) or mobile station (STA), may identify a number of spatial streams for a data transmission that is less than a number of transmit antennas, and may transmit a packet over a channel. In a first implementation, the packet may be formatted in a multi-user frame format, with a number of long training field (LTF) symbols equal to the number of transmit antennas. In a second implementation, the packet may be a null data packet (NDP), and the device may transmit a separate data packet. In a third implementation, the packet may be formatted in single-user frame format with a modified LTF. A receiving device may receive the packet, and may perform channel estimation and power amplifier (PA) distortion cancellation based on the received packet.

Abstract: Apparatuses and methods for correcting a distorted signal at a receiver device during wireless local area network (WLAN) communications are disclosed. The apparatuses and methods include receiving, by a receiver device in a WLAN, a distorted signal corresponding to a data packet signal transmitted from a transmitter device, receiving, by the receiver device, one or more transmitter parameters corresponding to the transmission of the data packet signal, the one or more transmitter parameters including information to adjust the distorted signal, and adjusting, by the receiver device, the distorted signal to reconstruct the data packet signal based at least on the one or more transmitter parameters.

Abstract: Methods, systems, and devices for wireless communication are described. A wireless device (e.g., an access point or a station) capable of supporting multiple chain configuration modes may dynamically select a chain configuration mode via channel analysis and energy efficiency analysis. A wireless device may monitor traffic on a wireless channel using a first chain configuration mode. The wireless device may determine an energy value associated with monitoring the traffic using the first (e.g., single) chain configuration, and further determine or infer an energy value associated with monitoring the traffic using a second (e.g., multi) chain configuration. The wireless device may perform a channel metric computation on the traffic (e.g., perform a QR decomposition of a channel matrix associated with the monitored traffic). The wireless device may then switch or select a chain configuration mode for operation based on a comparison between the determined energy values and the channel metric computation.

Abstract: A device includes one or more antennas configured to receive a first signal and a second signal from a second device. The first signal includes a non-precoded signal. The device further includes a receiver coupled to the one or more antennas. The receiver is configured to determine a first channel estimate based on the first signal and determine a second channel estimate based on the second signal. The receiver is also configured to determine an estimated distortion based at least in part on the first channel estimate and the second channel estimate. The receiver is further configured to perform a distortion reduction operation on the second signal based on the estimated distortion to generate a reduced-distortion signal.

Abstract: A method includes receiving a signal at a receiver device via a channel from a transmitter device and determining a frequency domain representation of the signal. The signal includes multiple modulation symbols. The method further includes detecting a first symbol of the signal and determining a time domain representation of a distortion estimate associated with the first symbol using a distortion recovery receiver (DRR) technique. The method further includes subtracting the distortion estimate from the first symbol to generate an updated estimate of the first symbol. The method further includes determining a frequency domain representation of a second symbol using a value that is based on a frequency domain representation of the distortion estimate and that is further based on a frequency domain representation of a quantized version of the updated estimate of the first symbol.

Abstract: Apparatuses and methods are disclosed for receiving or obtaining wireless signals. A first wireless device may receive a wireless signal including a first signal and a number of second signals. The first signal may contain data intended for the first wireless device, and the number of second signals may contain data intended for one or more second wireless devices. The first wireless device may select one or more of the number of second signals, determine a pre-whitening matrix based on an interference and noise covariance of the unselected second signals, and recover the first signal by using the pre-whitened signal.

Abstract: Methods, systems, and devices for wireless communication are described. A wireless device may transmit and receive signals using radio frequency (RF) chains associated with multiple radios configured for different radio access technologies (RATs). The wireless device may determine a signal of interest for each physical antenna of a set of RF chains associated with a RAT used to receive a desired signal. RF chains of the wireless device may be mapped to a virtual antenna configuration, which may be used to mitigate interference and subsequently process the desired receive signal. A determined interference channel may be used along with the determined signal of interest to map the RF chains to the virtual antenna configuration.

Abstract: Methods, systems, and devices for wireless communication are described. A wireless device may receive a signal using a plurality of radio frequency (RF) chains, and may digitally sample the signal over a period of time at outputs of the plurality of RF chains. The sampling may result in a plurality of sample time vectors. The device may map the digitally sampled signal to a set of one or more virtual antenna ports. The mapping may be performed for one or more observation sets of digital samples of the signal. Each observation set may represent a window of sample time vectors. The device may process a signal of interest (SoI) by processing digital samples associated with the set of one or more virtual antenna ports. The device may identify an interference channel contributing to interference of the SoI, and the mapping may be based on mitigating the interference of the SoI.

Abstract: Systems and methods are disclosed for decoding wireless signals. For example, a wireless device may receive a wireless signal, de-interleave the received wireless signal to produce a first encoded signal and a second encoded signal, generate a first set of a priori log likelihood ratios (LLRs) by decoding and de-interleaving the first encoded signal, and recover a set of information bits from the received wireless signal based at least in part on the second encoded signal and the first set of a priori LLRs.

Abstract: Antenna systems and methods for Massive Multi-Input-Multi-Output (MIMO) (M-MIMO) communication are provided. Antennas systems include a M-MIMO transmitter architecture with a hybrid matrix structure. The hybrid matrix structure protects against transmit path component failures and ensures that a spatial rate of the M-MIMO transmitter is not degraded by the failures. Antenna systems and methods also include antenna selection schemes for selecting a subset of antennas from a plurality of antennas to transmit to a receiver.

Abstract: Methods, systems, and devices for wireless communication are described. A wireless communication device may receive multiple data streams from one or more users, associate the multiple data streams with different user groups, and identify modulation symbols for the users after reducing signal contribution from modulation symbols associated with different user groups. For example, the device may receive a signal including multiple spatial streams, partition the data streams into different user groups, and determine a set of sequences from channel characteristics associated with the respective user groups. The wireless communication device may then apply the sequences to the received signal and to values associated with the channel characteristics. Subsets of values may be selected following the application of the sequences, and from the subsets of values, the wireless communication device may identify the sets of modulation symbols associated with one or more of the user groups.

Abstract: An interference suppression (IS) time/frequency zone for improved interference suppression at the user equipment (UE) is provided. The IS time/frequency zone can be scheduled and set up using existing signaling of the Almost Blank Subframe (ABS) framework. This includes using the existing signaling of the ABS framework to schedule the IS time/frequency zone, coordinate transmission parameters among base stations for the IS time/frequency zone, and signal the IS time/frequency zone to the UE. In another aspect, interfering base stations align respective reference signals during the IS time/frequency zone, which allows the UE to measure the channels from its serving base station and/or the interfering base stations(s). With channel state information knowledge at the UE, interference alignment can be achieved at the UE during the IS time/frequency zone.

Abstract: Systems and methods for enabling a wireless backhaul network between access points (APs) in a wireless network are provided. In an embodiment, the wireless backhaul network is enabled using a Massive Multiple Input Multiple Output (MIMO) radio access technology (RAT). In another embodiment, the wireless backhaul network is established using the same RAT as used by the APs to serve user devices, and can utilize the same time and frequency resources used for user communication.

Abstract: A framework for enabling a user equipment (UE) to apply interference suppression processing during network conditions that are favorable to interference suppression or that are known is provided. The framework includes an interference suppression (IS) time and frequency (time/frequency) zone, which can be scheduled by a serving base station and signaled to the UE. In an embodiment, the serving base station coordinates with the interfering base station(s) to create a network condition favorable to interference suppression at the UE during the IS time/frequency zone. In another embodiment, the serving base station opportunistically schedules the IS time/frequency zone for the UE whenever it determines favorable transmission parameters being used or scheduled for use by the interfering base station(s). The UE applies interference suppression processing within the IS time/frequency zone, thereby improving receiver performance.

Abstract: A dual-modem device opportunistically switches between spatial filtering techniques to enhance the received symbol estimates based at least in part on identifying, at a first modem, an interfering communication from a second modem. A WLAN modem can determine the timing of a WWAN transmission from a coexisting WWAN modem that interferes with a WLAN transmission and toggle between MRC and IRC receive techniques based at least in part on the determined timing.

Abstract: A dual-modem device opportunistically switches between spatial filtering techniques to enhance the received symbol estimates based at least in part on identifying, at a first modem, an interfering communication from a second modem. A WLAN modem can determine the timing of a WWAN transmission from a coexisting WWAN modem that interferes with a WLAN transmission and toggle between MRC and IRC receive techniques based at least in part on the determined timing.

Abstract: Methods, systems, and devices are described for wireless communications. A wireless device may process a first data signal sample using a wireless local area network (WLAN) processing path in a first receive chain of the wireless device. The wireless device processes a second data signal sample using a wireless wide area network (WWAN) processing path in a second receive chain of the wireless device. The wireless device time aligns the second data signal sample with the first data signal sample for data processing.

Abstract: Systems and methods are disclosed that may detect data transmitted using MIMO communications. Data may be received, on a wireless channel, as a plurality of spatial streams. A channel matrix characterizing the wireless channel may also be received. The channel matrix may be decomposed into a first sub-channel matrix and a second sub-channel matrix, each having a lower dimension than the channel matrix. A first estimated data signal may be generated based at least in part on the plurality of spatial streams and the first sub-channel matrix. A second estimated data signal may be generated based at least in part on the plurality of spatial streams and the second sub-channel matrix. The first and second estimated data signals may be combined to recover the data.

Abstract: In a communications network with carrier aggregation (CA), embodiments enable the network to advertise to a supported wireless device not only whether or not aggregated component carriers allocated to the wireless are intra-band adjacent but further whether or not the allocated component carriers are collocated. Embodiments further enable the wireless to advertise its CA capabilities including the support of adjacent collocated CA and/or non-adjacent collocated CA. Embodiments thus provide systems/methods for the exploitation of special conditions provided by adjacent collocated component carriers to reduce processing complexity and power consumption for certain types of wireless device transmitter/receiver architectures and to support intra-band adjacent CA for other types of UE transmitter/receiver architectures.