Receiver, receiver for positioning system using the same, and positioning method
AssigneeHitachi, Ltd.
InventorsRyosuke FUJIWARA, Kenichi Mizugaki, Masayuki Miyazaki
Life of this patent
Estimating the term…
Abstract
An invention for estimating the first path of an arrival signal by a method and device with a simple structure and lower power consumption. In this method, the nominal pulse repetition frequency or its integer multiple are A/D converted at a frequency less than the multiplicative inverse of the pulse width, the AD conversion timing is offset by time resolution Δt and the receive signal measured, data stored in a RAM, and the first path output time is estimated based on sequentially rearranging of the stored waveform data.
Claims20
A receiver comprising:
- a waveform measuring unit to perform multiple analog-to-digital conversions on the received signal while shifting the timing at each Δt at a frequency identical to the nominal pulse repetition frequency of a transmit signal made up of intermittent pulse signals subjected to direct spreading or an integer multiple of the same frequency, and at a frequency lower than the multiplicative inverse of the pulse width, and store the observation data from the receive signal in a storage area;
- and
- a first path estimator unit to estimate the arrival time of the first path arriving earliest time-wise in the receive signal, based on the stored observation data from the receive signal.
A positioning system receiver comprising:
- a terminal for transmitting a positioning signal;
- a reference station for sending a reference signal;
- a plurality of base stations for receiving the positioning signal and the reference signal;
- and
- a positioning server for calculating the position of the terminal and a network connecting the base station with the positioning server,
- wherein each base station comprises:
- a waveform observation unit to perform multiple analog-to-digital conversions on the received signal while shifting the timing at each Δt at a frequency identical to the nominal pulse repetition frequency of a transmit signal made up of intermittent pulse signals subjected to direct spreading, or an integer multiple of the same frequency, and at a frequency lower than the multiplicative inverse of the pulse width, and storing the peak value at each timing as receive signal observation data in a storage area;
- a first path estimator unit for estimating the arrival time of the first path arriving earliest time-wise in the receive signal, based on the stored multiple arrival time observation data;
- a time differential measurement unit for measuring the receive time differential between the reference signal and the positioning signal by using the clock signal, based on the first path arrival time of each receive signal;
- and
- a transmit unit for transmitting the time information containing the differentials in receive times to the positioning server, and
- wherein the positioning server comprises a position calculator unit to calculate the position of the terminal based on the time transmitted from each base station.
A positioning method for a terminal in a wireless device including a terminal for transmitting a positioning signal, a reference station for sending a reference signal and, multiple base stations for receiving the positioning signal and the reference signal and, a positioning server for calculating the position of the terminal and a network connecting the positioning server with the base station, the positioning method comprising the steps of:
- in each base station,
- performing multiple analog-to-digital conversions on the received signal while shifting the timing at each Δt at a frequency identical to the nominal pulse repetition frequency of a transmit signal made up of intermittent pulse signals subjected to direct spreading, or an integer multiple of the same frequency, and at a frequency lower than the multiplicative inverse of the pulse width, and storing the peak value at each timing as receive signal observation data in a storage area;
- estimating the arrival time of the first path arriving earliest time-wise in the receive signal based on the stored multiple arrival time observation data;
- measuring the receive time differential between the reference signal and the positioning signal by using the clock signal based on the first path arrival time of each receive signal;
- and
- transmitting the time information containing the differential in receive times to the positioning server, and
- in the positioning server,
- calculating the position of the terminal based on the time transmitted from each base station.
Dependencies are inferred from the claim text.