This disclosure describes systems, methods, and devices related to correlation reduction. A device may generate a sequence of pseudo-random symbols associated with a sounding signal to be transmitted to a first station device. The device may apply a modifier to the sequence of pseudo-random symbols. The device may generate a secure sounding signal from the modified sequence of pseudo-random symbols. The device may send the secure sounding signal to a first station device.

Systems and methods for low power wireless device detection are provided. In one or more implementations, a transmitting/advertising device may include a device identifier and/or one or more time-offset bits in a wireless communication frame for a scanning/receiving device. The scanning/receiving device may perform sequence-level correlation operations to detect the presence of the transmitting/advertising device. The sequence-level correlation operations may detect the transmitting/advertising device based on a detection of a correlation signal peak corresponding to the device identifier, and/or based relative timing of the correlation signal peak corresponding to the device identifier and a correlation signal peak corresponding to another item in the wireless communication frame.

In an aspect, a user equipment may receive assistance information for one or more index modulated sensing waveforms. The user equipment may receive index modulated sensing signals, the index modulated sensing signals based on the one or more index modulated sensing waveforms. The user equipment may process the index modulated sensing signals using at least some of the assistance information.

A communication unit for performing soft-decision demodulation comprises a receiver that receives a transmitted signal having a first set of bits comprising k bits, selected from a set of 2.sup.k possible signals according to values of the k bits, and a second set of bits comprising Q.sub.m bits based on a phase rotation of the transmitted signal selected from a set of 2.sup.Qm possible rotations. The receiver comprises: a demodulator comprising a bank of 2.sup.k correlators and is configured to: detect a transmission of each possible transmitted signal, and output 2.sup.k phases of the correlator outputs as a third set of inputs. A de-mapper circuit receives the third set of inputs: determines statistics derived from a number of aggregated correlator output phase distributions of the third set of inputs; and calculates and outputs a second set of aposteriori soft bits comprising Q.sub.m soft bits.

A radio frequency (RF) communications system may include a first RF node that transmits data, including a new frequency of operation, and a sequence of pilot symbols spread with a complex spreading code sequence. A second RF node may receive an incoming signal from the first RF node and perform despreading for N sample offset delays to generate N despreading sequences for the sequence of pilot symbols. The second RF node may perform a cross-correlation to select a desired despreading sequence from the N despreading sequences, determine a phase offset and timing offset, process the incoming signal based upon the desired despreading sequence, phase offset and timing offset, and switch to the new frequency of operation.

A radio frequency (RF) communications system may include a first RF node that transmits data, including a new frequency of operation, and a sequence of pilot symbols spread with a complex spreading code sequence. A second RF node may receive an incoming signal from the first RF node and perform despreading for N sample offset delays to generate N despreading sequences for the sequence of pilot symbols. The second RF node may perform a cross-correlation to select a desired despreading sequence from the N despreading sequences, determine a phase offset and timing offset, process the incoming signal based upon the desired despreading sequence, phase offset and timing offset, and switch to the new frequency of operation.

In an aspect, a user equipment may receive assistance information for one or more index modulated sensing waveforms. The user equipment may receive index modulated sensing signals, the index modulated sensing signals based on the one or more index modulated sensing waveforms. The user equipment may process the index modulated sensing signals using at least some of the assistance information.