A first device includes: a first reference signal source; a first transmitting/receiving unit which transmits two or more first carrier signals and receives two or more second carrier signals using an output of the first reference signal source; and a calculating unit. A second device includes: a second reference signal source configured to be operated independently from the first reference signal source; and a second transmitting/receiving unit configured to transmit two or more second carrier signals and receive two or more first carrier signals using an output of the second reference signal source. A frequency group of two or more first carrier signals and a frequency group of two or more second carrier signals differ from each other. The calculating unit calculates a distance between the first device and the second device based on a phase detection result obtained by receiving the first and second carrier signals.

Disclosed is a method for improving affinity of an antibody for an antigen, comprising, in an unmodified antibody, improving affinity for an antigen as compared to the unmodified antibody, by changing 77th, 79th and 81st amino acid residues of a light chain defined by Kabat method to charged amino acid residues.

Disclosed is a method for improving affinity of an antibody for an antigen, comprising, in an unmodified antibody, improving affinity for an antigen as compared to the unmodified antibody, by changing 77th, 79th and 81st amino acid residues of a light chain defined by Kabat method to charged amino acid residues.

A security system includes a portable terminal, a communication device communicating with the portable terminal, and a determination unit determining validity of the portable terminal. Phase data acquired from distance measuring radio wave is used to determine validity of communication between the portable terminal and the communication device. The received phase data of the distance measuring radio wave varies according to the distance from a transmission source. When the communication device and the portable terminal are fixed, and the communication device and the portable terminal have transmitted and received distance measuring radio waves having the same specific frequency, vehicle acquisition phase data and terminal acquisition phase data are the same. The determination unit determines, by using this two types of phase data, the validity of communication between the communication device and the portable terminal is determined.

A security system includes a portable terminal, a communication device communicating with the portable terminal, and a determination unit determining validity of the portable terminal. Phase data acquired from distance measuring radio wave is used to determine validity of communication between the portable terminal and the communication device. The received phase data of the distance measuring radio wave varies according to the distance from a transmission source. When the communication device and the portable terminal are fixed, and the communication device and the portable terminal have transmitted and received distance measuring radio waves having the same specific frequency, vehicle acquisition phase data and terminal acquisition phase data are the same. The determination unit determines, by using this two types of phase data, the validity of communication between the communication device and the portable terminal is determined.

A distance estimation device includes: a portable terminal; a communication device; a distance estimation unit estimating a distance between the portable terminal and the communication device; and a phase determination unit. The communication device determining a phase shift amount from a reference phase following a predetermined generating rule and generates measuring data by applying the determined phase shift amount. The phase determination unit determines a distance estimation phase for distance estimating purpose. The distance estimation unit adopts an estimated distance when a difference between the estimated distances respectively calculated based on at least two sets of combinations of the distance estimation phases is within a predetermined range.

An example wireless audio electronic device includes a first antenna, a communication circuit, and a processor. The processor may be configured to receive a positioning signal from an external electronic device through the first antenna so as to obtain first positioning information; obtain, from a different audio device located in a case together with the wireless audio electronic device, second positioning information for the positioning signal received by the different wireless audio electronic device; determine an angle of arrival of the positioning signal based on the first positioning information, the second positioning information, and the distance between the wireless audio electronic device and the different wireless audio electronic device; and transmit a response signal including information of the angle of arrival to the external electronic device.

An example wireless audio electronic device includes a first antenna, a communication circuit, and a processor. The processor may be configured to receive a positioning signal from an external electronic device through the first antenna so as to obtain first positioning information; obtain, from a different audio device located in a case together with the wireless audio electronic device, second positioning information for the positioning signal received by the different wireless audio electronic device; determine an angle of arrival of the positioning signal based on the first positioning information, the second positioning information, and the distance between the wireless audio electronic device and the different wireless audio electronic device; and transmit a response signal including information of the angle of arrival to the external electronic device.

Secure range estimates as described herein may include determining a range estimate between two Bluetooth enabled devices based, at least in part, on round trip phase measurements of wireless signals transmitted between the devices. In one example, a range estimate may include determining a first set of relative carrier measurements at a first set of frequencies, determining a second set of relative carrier measurements based on the first set at the second set of frequencies; and combining the first set and the second set to estimate a distance between the devices.

Secure range estimates as described herein may include determining a range estimate between two Bluetooth enabled devices based, at least in part, on round trip phase measurements of wireless signals transmitted between the devices. In one example, a range estimate may include determining a first set of relative carrier measurements at a first set of frequencies, determining a second set of relative carrier measurements based on the first set at the second set of frequencies; and combining the first set and the second set to estimate a distance between the devices.