Receiving apparatus, communication apparatus and control apparatus using the same

• US 20070116104A1
• Filed: 11/14/2006
• Published: 05/24/2007
• Est. Priority Date: 11/18/2005
• Status: Active Grant

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: Renesas Technology Corporation (Renesas Electronics Corporation)
• Inventors: Miyazaki, Masayuki, Nakagawa, Tatsuo, Fujiwara, Ryosuke
• Granted Patent: US 7,830,953 B2
• Time in Patent Office: Days
• US Class Current: 375/149
• CPC Class Codes: H04B 1/7183 Synchronisation
• CPC Class Codes: H04L 7/0058 detection of error based on equalizer tap values
• CPC Class Codes: H04L 7/10 Arrangements for initial synchronisation

Abstract

The present invention conducts the initial synchronization acquisition of the rapid and high precision ultra-wideband signal without complicatedness of hardware and increase in power consumption. For this purpose, a communication apparatus for exchanging information with an intermittent pulse train signal searches all phases among the pulses in the predetermined search resolution in the process to acquire initial synchronization of the input pulse, estimates the region where the peak phase of the largest output value exists, narrows the region where the peak phase exists up to the predetermined range by repeating the search for all phases in the estimated region in the next step, and conducts acquisition of detailed synchronization in the estimated region. In every step, the threshold value for judging existence of signal or a gain in the analog circuit is controlled for each step. Moreover, the search resolution is set coarse for estimation of the peak phase and set fine for acquisition of detailed synchronization.

Claims

1. A receiving apparatus for sampling and receiving a transmitting signal transmitted based on a communication system for exchanging information with an intermittent pulse train signal in the nominal pulse repetition frequency or the frequency of the integer times thereof, the receiving apparatus comprising:

an initial synchronization acquiring device for synchronizing sampling timing of a receiving signal to pulse location or pulse phase before demodulation of the receiving signal,

wherein the initial synchronization acquiring device comprises;

a peak search function for holding the largest output value as the peak value by searching all phases corresponding to the frequency of the transmitting signal with a first search resolution, judging existence of the receiving signal from the peak value, and estimating a new peak phase estimated region from the phase region including phase of the peak value and being narrowed than the all phases when the receiving signal exists; and

a detailed synchronization acquiring function for searching, in a second search resolution, the peak phase estimated region estimated with the peak search function.

2. The receiving apparatus according to claim 1,

wherein the peak search function repeats a plurality of times of the processes for holding the largest output value as a peak value by searching all phases of the new peak phase estimated region with the first search resolution or a search resolution higher than the first search resolution and moreover estimating a new peak phase estimated region from the phase region including the phase of the peak value and being narrowed than the peak phase estimated region.

3. The receiving apparatus according to claim 2,

wherein the peak search function repeats the processes until the peak phase estimated region becomes equal to or narrower than the pulse width TW of the transmitting signal.

4. The receiving apparatus according to claim 1, further comprising:

an amplifier for amplifying the received transmitting signal in the predetermined amplification factor in a preceding stage of the peak search,

wherein the peak search function changes the amplification factor in accordance with the largest output value being held.

5. The receiving apparatus according to claim 1,

wherein the peak search function comprises a threshold value determining unit for determining existence of a signal in the peak search function or in the detailed synchronization acquiring function, and changes the threshold value in accordance with the largest output value being held.

6. The receiving apparatus according to claim 1,

wherein the second search resolution in the detailed synchronization acquiring function is set higher than the first search resolution in the peak search function.

7. The receiving apparatus according to claim 1,

wherein the output value inputted for the peak search and the detailed synchronization acquisition is an output of a matched filter having a spread code sequence same as that of the transmitting signal as a tap coefficient.

8. The receiving apparatus according to claim 1, further comprising:

a function for conducting sampling in a phase leading the original timing of sampling in the nominal pulse repetition frequency or in the frequency of an integer times thereof;

a function for conducting sampling in a phase delayed from the original timing;

a function for despreading the signals sampled in the leading and delayed phases using the spread code of the transmitting signal;

a function for obtaining a difference from the two despread signals; and

a function for controlling the timings of the three samplings from the difference signal.

9. The receiving apparatus according to claim 1,

wherein the output value inputted for the peak search and the detailed synchronization acquisition is a power element or an amplitude element calculated from a couple of outputs obtained by sampling the frequency-converted signal divided into two quadrature signals generated by multiplying the receiving signal with the signals deviated in the phase by 90 degrees having the carrier frequency of the transmitting signal and eliminating a high frequency element in the nominal pulse repetition frequency or the frequency of the integer times thereof and by inputting the same signal to the matched filter having the spread code sequence of the transmitting signal as the tap coefficient.

10. The receiving apparatus according to claim 1,

wherein the initial synchronization acquiring device obtains the clock for giving the timing of the sampling by dividing the frequency of the signal having the frequency equal to the integer times of the nominal pulse repetition frequency, and

wherein the initial synchronization acquiring device conducts phase shift for the peak search and the detailed synchronization acquisition by varying the frequency dividing number.

11. The receiving apparatus according to claim 9,

wherein the initial synchronization acquiring device obtains the clock for giving the timing of sampling by dividing the frequency of the signal having the frequency equal to the integer times of a nominal pulse repetition frequency,

wherein the initial synchronization acquiring device conducts phase shift for the peak search and the detailed synchronization acquisition by varying the frequency division number, and

wherein the initial synchronization acquiring device uses the signal having the carrier frequency of the transmitting signal as the signal having the frequency equal to the integer times of the nominal pulse repetition frequency.

12. The receiving apparatus according to claim 9,

wherein the peak search function has a function for estimating a frequency deviation between the carrier frequency of the transmitting signal and the oscillation frequency of a receiver from the frequency-converted signal divided into two quadrature signals, and rotates the phase by the complex multiplication of a complex number in accordance with the estimation result of the frequency deviation with the couple of signals divided into two quadrature signals.

13. The receiving apparatus according to claim 1,

wherein the initial synchronization acquiring device further comprises:

a function for conducting the sampling in a phase leading the original timing of sampling in the nominal pulse repetition frequency or the frequency of an integer times thereof;

a function for conducting the sampling in a phase delayed from the original timing;

a function for despreading the signals sampled with two phases with the spread signal in the transmitting signal;

a function for obtaining a difference from the two despread signals; and

a function for controlling the timings of the three samplings from the difference signal, and

wherein the peak search function and the detailed synchronization acquiring function input the signal obtained by synthesizing the signals sampled in the two phases and demodulate the signal obtained by synthesizing the signals sampled in the two phases.

14. A receiving apparatus for receiving a transmitting signal transmitted based on a communication system for exchanging information with an intermittent pulse train signal in the nominal pulse repetition frequency or an integer times thereof as a receiving signal, comprising:

an initial synchronization acquiring device for synchronizing a sampling timing of the receiving signal to a pulse location or a pulse phase before demodulation of the receiving signal,

wherein the initial synchronization acquiring device comprises;

a peak search function for holding the largest output value as a peak value by searching all phases corresponding to the frequency of the transmitting signal, judging existence of the receiving signal from the peak value, and estimating a new peak phase estimated region from the region including the phase of the peak value and being narrower than all phase regions corresponding to the frequency when the receiving signal exists; and

a detailed synchronization acquiring function for conducting acquisition of detailed synchronization in the peak phase estimated region estimated with the peak search function, and

wherein the peak search function repeats the processes until the peak phase estimated region becomes equal to or narrower than the pulse width TW of the transmitting signal.

15. The receiving apparatus according to claim 14,

wherein the peak search function comprises at least a function for changing an amplification coefficient for amplifying the received transmitting signal in the preceding stage of the peak search, and a function for changing the threshold value for judging existence of the peak phase, and changes the amplification factor or the threshold value in accordance with the largest peak value being held.

16. The receiving apparatus according to claim 14, further comprising:

an analog to digital converter for conducting analog-to-digital conversion in the nominal pulse period of the input pulse train or in the period of an integer times thereof; and

a timing signal generator for supplying the clock to give the conversion timing,

wherein the input pulse is synchronized with the timing of the analog-to-digital conversion in the initial synchronization acquisition, and search resolution in the initial synchronization acquisition is raised by shifting the phase of timing in the conversion.

17. A communication apparatus comprising a transmitting function and a receiving function for exchanging information with an intermittent pulse train signal,

wherein the receiving function includes an initial synchronization acquiring device for initial synchronization acquisition of the input pulse train, and

wherein the initial synchronization acquiring device comprises:

a peak search function which searches all phases among the pulses in the predetermined search resolution, estimates the region where the peak phase having the largest output value of the input pulse train exists, and narrows the estimated region of the peak phase until the predetermined range is obtained by repeating the search of all phases within the estimated region; and

a detailed synchronization acquiring function for conducting synchronization acquisition of the peak phase in the search resolution higher than the search resolution in the peak search function within the narrowed estimating phase region.

18. The communication apparatus according to claim 17,

wherein the peak search function comprises at least a function for changing, in the narrowing process, an amplification factor for amplifying the pulse train signal received in the preceding stage of the peak search, and the function for varying the threshold value for judging existence of the peak phase.

19. A control apparatus comprising:

a UWB communication apparatus provided with a UWB receiver;

a UWB transmitter;

a baseband unit including a communication apparatus for exchanging information with an intermittent pulse train by having a transmitting function and a receiving function; and

a processor,

wherein the control apparatus further includes a function for transmitting the data obtained from sensors connected to the control apparatus to the central processing unit with the UWB-IR radio communication through an arithmetic process by the processor,

wherein the receiving function of the communication apparatus has an initial synchronization acquiring device for initial synchronization acquisition of the input pulse, and

wherein the initial synchronization acquiring device comprises;

a peak search function which searches all phases among the pulses in the predetermined search resolution, estimates the region where the peak phase having the largest output value of the input pulse train exists, and narrows the estimated region of the peak phase until the predetermined range can be obtained by repeating the search of all phases within the estimated region; and

a detailed synchronization acquiring function for conducting, in the narrowed phase estimated region, the synchronization acquisition of peak phase in a search resolution higher than that of the peak search function.

20. The control apparatus according to claim 19, further comprising:

a function for transmitting the state of apparatuses mounted in an automobile detected by the sensors to the mounted central processing unit by the UWB-IR radio communication by processing such state with the processor; and

a function for controlling an actuator to drive the apparatuses through the arithmetic process with the processor by receiving the manipulation instruction to the apparatuses with the UWB-IR radio communication from the central processing unit.