A receiver circuit includes a feedback loop including a device. The receiver circuit also includes a register and a sequencer. The sequencer is configured to, responsive to an error signal being below a threshold value, cause the register to store a value indicative of the state of the feedback loop. The sequencer is also configured to cause the feedback loop to transition to a lower power state, and, responsive to a detected wake-up event, cause the previously stored value indicative of the state of the feedback loop to be loaded from the register into the device and enable the feedback loop.

Techniques for blind distributed multi-user MIMO enable simultaneous decoding of multiple concurrent wireless transmissions without the need for coordination between wireless devices or a measurement phase. Wireless devices are permitted to transmit independently and at arbitrary times. Concurrent transmissions from wireless devices superimpose in the wireless channel and are received at various base stations. The base stations forward received data samples to a central entity (e.g., a cloud computing service), which uses known preambles to reliably estimate CFOs and channels between the transmitting devices and the receiving base stations while simultaneously recovering the data samples of the individual data streams.

A method of contactless communication can be performed between an object and a reader using active load modulation. A synchronization process is performed between a first carrier signal transmitted by the reader and having a reference frequency, and a second carrier signal extracted from an output signal of a controlled oscillator of a digital phase-locked loop of the object. In the synchronization process, as long as a locking of the loop has not been detected, the frequency of the output signal of the oscillator is latched on a frequency that is a multiple of the reference frequency. Once the locking has been detected, the latching continues while controlling the oscillator with a second control signal generated from a second value obtained.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may determine a first set of parameters based at least in part on a first reference signal received from a first transmit receive point (TRP) and a second set of parameters based at least in part on a second reference signal received from a second TRP; determine a common parameter using the first set of parameters and the second set of parameters; and perform a tracking loop operation using the common parameter or the first set of parameters and the second set of parameters, wherein the tracking loop operation comprises at least one of a frequency tracking loop operation or a time tracking loop operation. Numerous other aspects are provided.

A method of contactless communication can be performed between an object and a reader using active load modulation. A synchronization process is performed between a first carrier signal transmitted by the reader and having a reference frequency, and a second carrier signal extracted from an output signal of a controlled oscillator of a digital phase-locked loop of the object. In the synchronization process, as long as a locking of the loop has not been detected, the frequency of the output signal of the oscillator is latched on a frequency that is a multiple of the reference frequency. Once the locking has been detected, the latching continues while controlling the oscillator with a second control signal generated from a second value obtained.

Provided are a configuration method and a transmission method of a new reference signal for frequency offset estimation in a novel wireless communication system. The method may include configuring a synchronization signal to be transmitted through a first bandwidth part of one or more bandwidth parts configured by dividing an entire bandwidth into one or more parts, allocating the one or more reference signals for estimating the frequency offset on one or more resources other than a resource for configuring the synchronization signal, and transmitting the one or more reference signals for estimating the frequency offset.

Provided are a configuration method and a transmission method of a new reference signal for frequency offset estimation in a novel wireless communication system. The method may include configuring a synchronization signal to be transmitted through a first bandwidth part of one or more bandwidth parts configured by dividing an entire bandwidth into one or more parts, allocating the one or more reference signals for estimating the frequency offset on one or more resources other than a resource for configuring the synchronization signal, and transmitting the one or more reference signals for estimating the frequency offset.

A communication packet (PHY packet) can include a plurality of subfields with a common symbol sequence that can be used for autocorrelation. The symbol sequence of each subfield may be multiplied by a constant of either +1 or 1, based on a different bit of a maximal length sequence, which can enable cross-correlation. Thus, this packet design enables packet detection, symbol timing recovery, and carrier frequency offset estimation.

Provided are a configuration method and a transmission method of a new reference signal for frequency offset estimation in a novel wireless communication system. The method may include configuring a synchronization signal to be transmitted through a first bandwidth part of one or more bandwidth parts configured by dividing an entire bandwidth into one or more parts, allocating the one or more reference signals for estimating the frequency offset on one or more resources other than a resource for configuring the synchronization signal, and transmitting the one or more reference signals for estimating the frequency offset.

An automatic frequency control (AFC) device is provided. The AFC device includes an input module, a received signal strength indicator (RSSI) module and a carrier frequency offset (CFO) estimation module. The input module down converts and samples a received signal. The RSSI module is coupled to the input module and calculates a RSSI signal in response to the down converted and sampled received signal. The CFO estimation module is coupled to the input module and the RSSI module and calculates a moving average of binary elements of the down converted and sampled received signal. The CFO estimation module continues to calculate the moving average until the AFC converges.