摘要:
Methods, systems, and devices for wireless communications are described. One example includes calculating one or more first channel capacities for each precoder hypothesis of a first subset of precoder hypotheses and selecting a first precoder hypothesis of the first subset of precoder hypotheses using the calculated first channel capacities. The example also includes selecting a second subset of precoder hypotheses based on the first precoder hypothesis, calculating one or more second channel capacities for each precoder hypothesis of the second subset of precoder hypotheses, and selecting a second precoder hypothesis of the second subset of precoder hypotheses using the calculated second channel capacities. The example also includes selecting grouping co-phase factors based at least in part on the first precoder hypothesis or the second precoder hypothesis and transmitting a first precoding matrix indicator that indicates a first precoder index based on the one or more grouping co-phase factors.
摘要:
Methods, systems, and devices for maximizing signal to interference plus noise ratio of a channel in a location tracking system. The methods, systems, and device may include tools and techniques for minimizing interference from adjacent samples at a receive filter, may include relaxing constraints at a transmitter. A receive filter or set of receive, or both, filters may be determined and utilized by specifying and or determining various transmitter, receiver, and channel characteristics. The receive filter and set of filters may be determined through an iterative approach involving one or more solution metrics.
摘要:
Described are a system and method for correcting a receiver frequency at a receiver to enhance detection of arrival of a wirelessly transmitted message. In particular, a frequency offset between receiver frequency and a carrier frequency may be estimated based, at least in part, on an autocorrelation of a bit sequence in a received message.
摘要:
Methods, systems, and devices are described for maximizing transmit power of an ultra-wideband (UWB) pulse. A spectral mask and a spectral efficiency may be identified. A set of transmit filter coefficients may be generated at a fraction of a carrier frequency. The set of transmit filter coefficients may be based at least in part on the identified spectral mask and spectral efficiency. The UWB pulse may be transmitted with a shape defined at least in part by the set of transmit filter coefficients.
摘要:
Certain aspects of the present disclosure generally relate to jamming detection for radio frequency (RF) front-end circuitry. For example, certain aspects provide an apparatus having a first counter configured to count a number of times that a power of a reception signal exceeds a first threshold. The apparatus also includes a second counter configured to count a number of measurements of the power of the reception signal. The apparatus further includes control logic having a first input coupled to an output of the first counter and having a second input coupled to an output of the second counter. The control logic is configured to determine an amount of jamming over a measurement window based on the number of times that the power of the reception signal exceeds the first threshold and on the number of measurements.
摘要:
Methods, systems, and devices for wireless communications are described for low noise amplifier (LNA) configurations of a user equipment (UE) operating in a dual-subscriber dual-active (DSDA) mode. The UE may establish first and second communications links via two or more antenna ports using a first subscriber identity module (SIM) and a second SIM in the DSDA mode. The UE may identify a LNA configuration from two or more available LNA configurations for receiving at least partially concurrent communications of the first SIM and the second SIM based at least in part on activation of the DSDA mode and a difference between a first received signal strength associated with the first SIM and a second received signal strength associated with the second SIM. The UE may receive the at least partially concurrent communications via the two or more antenna ports based at least in part on the identified LNA configuration.
摘要:
Methods, systems, and devices for channel estimation in a location tracking system are described. The methods, system, and devices may include tools and techniques for determining and/or designing perfect or semi-perfect sequences (including preamble sequences) for implementation in a location tracking system. Sequences having 2's exponent dimensionality, such as ternary sequences, may be determined and employed, which may help reduce implementation complexity and/or operating power consumption. Sequences may be determined using mean square error and/or maximum autocorrelation peak performance metrics.
摘要:
Methods, systems, and devices for channel estimation in a location tracking system are described. The methods, system, and devices may include tools and techniques for determining and/or designing perfect or semi-perfect sequences (including preamble sequences) for implementation in a location tracking system. Sequences having 2's exponent dimensionality, such as ternary sequences, may be determined and employed, which may help reduce implementation complexity and/or operating power consumption. Sequences may be determined using mean square error and/or maximum autocorrelation peak performance metrics.
摘要:
Methods, systems, and devices for channel estimation and/or earliest path detection in a location tracking system are described. The described tools and techniques may involve accumulation of energy of multiple copies of a periodic sequence, which may be contained and/or associated with a signal transmitted from a location tracking tag. One or more access points within the location tracking system may receive and process multiple copies of the sequence, employing period-wise coherent accumulation, and estimate an earliest path, or a corresponding delay associated with an earliest path, of the sequence. The access point(s) may transmit information related to the earliest path, including the corresponding delay, to a tracking management server, which may use the information to estimate and/or determine a location of a tag.
摘要:
Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a receiver device may identify an analog to digital converter (ADC) clipping rate for one or more measurement windows. The receiver device may modify, based at least in part on a determination that the ADC clipping rate does not satisfy a threshold, a low noise amplifier (LNA) gain value to be used by the receiver device. The receiver device may receive a signal using the modified LNA gain value. Numerous other aspects are provided.