This application is a National Phase Patent Application and claims priority to and benefit of International Application Number PCT/CN2009/074287, filed on Sep. 28, 2009, the entire disclosure of which is incorporated herein by reference.
The present invention relates to a method to realize the fast synchronization in impulse system high speed ultra-wideband (UWB) wireless communication systems, and it falls in the technical field of short-distance wireless communication and dissemination of information.
As one of the core techniques in the future ubiquitous wireless communication, the UWB wireless communication technique has attracted wide attention in recent years, and its development has made remarkable progress.
The way to realize UWB technique can be generally divided into two basic implementation mode of impulse system and carrier wave system. The impulse system UWB transmits information by using baseband pulse sequence, has the advantages of simple system structure, low cost, low power consumption and the like, and has gained a wide range of applications in wireless communication, distance measurement, exploration fields; on the other hand, carrier wave system UWB, by using mature modulated continuous carrier wave and Orthogonal Frequency Division Multiplexing (OFDM) technology, etc., has gained high efficiency in spectrum utilization and flexibility in using spectrum resources. Under the impulse system UWB technology, the receiving end can use peak detection, energy detection, simulation correlation detection methods etc., hence its processing performance is restricted by simulation manipulation and generally only a lower speed wireless communication, exploration, positioning and other functions can be realized; the receiving end can also use high speed sampling methods and perform digital processing through low-precision quantification, hence it has the advantages of stable performance and easy integration, and can achieve a higher speed in wireless transmission.
In impulse-UWB of high speed sampling system, one of the difficulties is to achieve synchronization. In the existing synchronization method, it obtains estimation on synchronization position by using the periodic or pseudorandom characteristics of synchronization sequence and by performing energy correlation or sliding correlation on the sampled data. However, in the impulse-UWB system, since the sampling rate is extremely high, it can only carry out the quantification of the sampled value with low precision at one bit or two bits and produces large quantification noises due to the constraints on power consumption and processing capacity of the system, and hence the above-mentioned existing synchronization method can no longer be used. In this situation, a feasible method is to estimate the channel impulse response through the accumulation of multiple periodic signals, and to search the peak position of channel estimation in the cumulative process and to take this peak position as the synchronization reference position. This method is a sliding cumulative process and needs large amounts of calculation; further, because the peak position cannot be determined instantaneously, it is necessary to check over a long enough period of time before the determination can be reached, hence resulting in the need for large storage space and causing delay in processing.
Technical problems: The present invention provides a synchronization method applicable to impulse system UWB wireless communication systems of high speed sampling and low precision quantification, and it has the advantages of fast synchronization speed, high precision and low implementation complexity, etc.
Technical solutions: The synchronization method provided in this invention has the frame structure as shown in
In this method, the frame is the basic unit in data transmission. Each frame comprises a preamble symbol part and a data part, wherein the preamble symbol part transmits known pulse sequence which is used for channel estimation and synchronization, while the data part carries the information to be transmitted. The preamble symbol part further comprises two parts of positive and negative pulse sequence and co-current pulse sequence; the front part of which is the positive and negative pulse sequence and contains an odd number of impulses with alternant positive and negative polarities, while the rear part of which is the co-current pulse sequence and consists of impulses of same polarity; and the impulse polarity in the co-current pulse sequence is the same as the impulse polarity of the last impulse in positive and negative pulse sequence. The preamble symbol part has the same impulse interval.
The synchronization method is shown in
The beneficial effects: The synchronization method provided in this invention is applicable to the impulse system UWB wireless communication system of high speed sampling and low precision quantification. Compared with the existing synchronization methods, the method provided in the invention has the advantages of high synchronization precision, small storage space required, and ability to locate synchronization position in real-time, etc., and hence it has important values for the development of impulse system UWB wireless communication technique.
The embodiment of the invention:
The following is a embodiment of the invention.
The frame structure is shown in
The synchronization method is shown in
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/CN2009/074287 | 9/28/2009 | WO | 00 | 6/11/2012 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2011/035494 | 3/31/2011 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
7613257 | El Fawal et al. | Nov 2009 | B2 |
20100182993 | Jurgensen et al. | Jul 2010 | A1 |
Number | Date | Country |
---|---|---|
101079688 | Nov 2007 | CN |
101083482 | Dec 2007 | CN |
101667850 | Mar 2010 | CN |
2006-60736 | Mar 2006 | JP |
Entry |
---|
International Search Report, corresponding to PCT/CN2009/074287, dated Jul. 8, 2010, 6 pages. |
Number | Date | Country | |
---|---|---|---|
20120243577 A1 | Sep 2012 | US |