A receiver, including: a sampling circuit configured to convert a received analog signal into a digital signal; a variance determination circuit configured to determine a phase difference variance of the digital signal; and a frequency shift keying (FSK) discrimination circuit configured to discriminate, based on the phase difference variance, whether the received analog signal is an FSK-modulated signal.

Embodiments may provide a way of communicating via an electromagnetic radiator, or light source, that can be amplitude modulated such as light emitting diode (LED) lighting and receivers or detectors that can determine data from light received from the amplitude modulated electromagnetic radiator. Some embodiments may provide a method of transmitting/encoding data via modulated LED lighting and other embodiments may provide receiving/decoding data from the modulated LED lighting by means of a device with a low sampling frequency such as a relatively inexpensive camera (as might be found in a smart phone). Some embodiments are intended for indoor navigation via photogrammetry (i.e., image processing) using self-identifying LED light anchors. In many embodiments, the data signal may be communicated via the light source at amplitude modulating frequencies such that the resulting flicker is not perceivable to the human eye.

Embodiments may provide a way of communicating via an electromagnetic radiator, or light source, that can be amplitude modulated such as light emitting diode (LED) lighting and receivers or detectors that can determine data from light received from the amplitude modulated electromagnetic radiator. Some embodiments may provide a method of transmitting/encoding data via modulated LED lighting and other embodiments may provide receiving/decoding data from the modulated LED lighting by means of a device with a low sampling frequency such as a relatively inexpensive camera (as might be found in a smart phone). Some embodiments are intended for indoor navigation via photogrammetry (i.e., image processing) using self-identifying LED light anchors. In many embodiments, the data signal may be communicated via the light source at amplitude modulating frequencies such that the resulting flicker is not perceivable to the human eye.

A surgery navigation system according to the present invention includes: a positioning module including: a transceiver unit, configured to transmit a frequency modulated signal; multiple positioning marks, which are separately disposed on each vertebra of a spine and configured to transmit the positioning mark frequency signal to the transceiver unit after receiving the frequency modulated signal; and a surgical instrument, which transmits the instrument frequency signal to the transceiver unit after receiving the frequency modulated signal; and a processing unit, which obtains a distance between the positioning marks and the transceiver unit through calculation according to a difference between the positioning mark frequency signal and the frequency modulated signal, and obtains space coordinates of the spine through calculation according to the distance; and obtains a distance between the surgical instrument and the transceiver unit through calculation according to a difference between the instrument frequency signal and the frequency modulated signal, obtains space coordinates of the instrument through calculation according to the distance, and performs a surgery navigation operation according to the space coordinates of the spine and the space coordinates of the instrument.

An apparatus and method for processing a frequency offset of a pilot and a receiver where the includes: calculating a correlation function of a channel by using a receiving or received signal and a correlation length; calculating a phase to which the correlation length corresponds according to the correlation function; and calculating a corresponding slope according to phases to which at least two correlation lengths correspond when the phase to which the correlation length corresponds is greater than 2π, and estimating a frequency offset of a pilot of the channel based on the slope. Hence, estimation of a frequency offset of a pilot may be accurately achieved, thereby accurately judging channel spacing.

A method may comprise receiving and sampling a signal. The signal may encode a data packet. A slice may be generated and stored comprising a pair of values for each of a selected number of samples of the signal representing a correlation of the signal to reference functions in the receiver. The presence of the data packet may then be detected and the detected packet decoded from the stored slices. The generating and storing slices may be carried out as the received signal is sampled. The sampled values of the signal may be discarded as the slices are generated and stored. The slice representation of the signal can be manipulated to generate filters with flexible bandwidth and center frequency.

A method may comprise receiving and sampling a signal. The signal may encode a data packet. A slice may be generated and stored comprising a pair of values for each of a selected number of samples of the signal representing a correlation of the signal to reference functions in the receiver. The presence of the data packet may then be detected and the detected packet decoded from the stored slices. The generating and storing slices may be carried out as the received signal is sampled. The sampled values of the signal may be discarded as the slices are generated and stored. The slice representation of the signal can be manipulated to generate filters with flexible bandwidth and center frequency.

A wireless communication apparatus performs communication for which a receiving timing and a transmitting timing are defined by using time slots. The wireless communication apparatus includes a control circuitry configured to control the wireless communication apparatus. The control circuitry includes a decoding circuitry configured to start a decoding process, on data received in a first time slot, immediately after a start of a second time slot subsequent to the first time slot. When a result of the decoding process is information requesting the wireless communication apparatus to perform transmission, the control circuitry is configured to perform a transmission preparation process from an end of the decoding process to a start of a third time slot subsequent to the second time slot, within a period of the second time slot for enabling the wireless communication apparatus to perform transmission.

A wireless communication apparatus performs communication for which a receiving timing and a transmitting timing are defined by using time slots. The wireless communication apparatus includes a control circuitry configured to control the wireless communication apparatus. The control circuitry includes a decoding circuitry configured to start a decoding process, on data received in a first time slot, immediately after a start of a second time slot subsequent to the first time slot. When a result of the decoding process is information requesting the wireless communication apparatus to perform transmission, the control circuitry is configured to perform a transmission preparation process from an end of the decoding process to a start of a third time slot subsequent to the second time slot, within a period of the second time slot for enabling the wireless communication apparatus to perform transmission.

A method of transmitting a Physical Layer Convergence Procedure (PLCP) frame in a Very High Throughput (VHT) Wireless Local Area Network (WLAN) system includes generating a MAC Protocol Data Unit (MPDU) to be transmitted to a destination station (STA), generating a PLCP Protocol Data Unit (PPDU) by adding a PLCP header, including an L-SIG field containing control information for a legacy STA and a VHT-SIG field containing control information for a VHT STA, to the MPDU, and transmitting the PPDU to the destination STA. A constellation applied to some of Orthogonal Frequency Division Multiplex (OFDM) symbols of the VHT-SIG field is obtained by rotating a constellation applied to an OFDM symbol of the L-SIG field.