KR20060114747A - Baseband transceive of ultra wide band radio communication system - Google Patents

Abstract

A baseband transceiver of an ultra wide band radio communication system is provided to simplify a structure of the transceiver by transmitting and receiving in a shape of a baseband signal. In a baseband transceiver of an ultra wide band radio communication system, an input buffer unit(10) is composed of X number of buffers to form X x N bit data. A pulse matching filter unit(20) samples the X x N bit data as a chip frequency by using a coefficient inputted from a calculating unit(100). A mutual correlating unit(30) receives the chip frequency sampled by the pulse matching filter unit(20) and detects a position at which the pulse exists. A peak detection unit(40) detects a peak of the received data inputted from the mutual correlating unit(30). A phase acquisition/tracking unit(50) acquires a phase of the received data and tracks the acquired phase. A multiplexer(60) outputs a signal outputted from the selected mutual correlator. A multi-path calculator(80) generates phase shift and amplitude change information for the multi-path. A combiner(70) transceives the phase shift for the multi-path, the information for the amplitude change, and a signal inputted through the multiplexer(60) by using single antenna. And, a data reproduction unit(90) compensates a channel for each path by using the phase shift for the multi-path and the information for the amplitude change and reproduces the bits transceived per each symbol clock by comparing the compensated result with a reference value.

Description

BASEBAND TRANSCEIVE OF ULTRA WIDE BAND RADIO COMMUNICATION SYSTEM}

1 is a view for explaining the configuration of a baseband receiving apparatus according to the present invention;

2 is a view for explaining a detailed configuration of the pulse matching filter applied to FIG.

3 is a view for explaining the detailed configuration of the cross-correlator applied to FIG.

4 is a graph showing the results of cross-correlation for the output of the pulse matching filter and the spreading code in the cross-correlator of FIG.

5 is a state diagram for an operation mode;

6 is a phase tracking waveform diagram;

FIG. 7 is a diagram illustrating a detailed configuration of a multipath calculator applied to FIG. 1.

*** Explanation of symbols for the main parts of the drawing ***

10: input buffer part 20: pulse matching filter part

30: cross-correlator 40: peak detector

50: phase capture / tracker 60: multiplexer

70: Conbiner 80: Multipath Calculator

90: data playback unit

The present invention relates to a baseband receiving apparatus of an ultra wideband wireless communication system.

More specifically, by implementing an ultra-wideband wireless communication system for transmitting and receiving an ultra-wideband signal with less power than noise, ultra-wideband wireless communication for enabling high-speed communication at the Gbps level by using a very short pulse of nanoseconds is possible. It relates to a baseband receiving device of the system.

In particular, the baseband reception of the ultra-wideband wireless communication system, which not only simplifies the circuit and structure of the transmission and reception device by transmitting and receiving in the form of baseband signal, but also has low power consumption of less than one thousandth of existing communication equipment. Relates to a device.

Ultra Wide Band (UWB) technology overcomes the limitations of existing wireless communication technology by dealing with signals in the time domain, as opposed to handling signals in the frequency domain, which is the basis of communication. It is the next generation wireless communication method that makes efficient use of resources.

In addition, the UWB communication method that transmits information at low power and high speed is a technology suitable for building a human-centered digital environment system, and home appliances and information devices autonomously and actively grasp user's health, emotions, and surrounding conditions to provide necessary information. In preparation for the advent of the human-centered smart environment, the development of ultra-wideband wireless communication technology without frequency limitation, which is a core technology, is required.

Unlike conventional wireless communication systems using continuous sinusoidal waves, UWB wireless communication system transmits impulses with a very narrow width of less than 1 nsec at the transmitting end wirelessly through pulse position modulation (PPM), etc. Is demodulated using a correlator or the like.

Therefore, the UWB wireless communication system exhibits ultra-wideband characteristics with very low power over several GHz bands, and since signals are generally configured in the form of pulse trains, random time hopping and line spectrum suppression are performed by time coding. It is possible to have high incompatibility and low interference characteristics.

In addition, UWB system has high channel capacity and data rate, and it is easy to finely disassemble the multipath, so it can improve performance and precise location tracking through Rake reception, and reduce hardware implementation cost by eliminating RF and IF stages. Can be.

On the other hand, very precise synchronization is required for PPM and time leap, and the antenna design is complicated due to the ultra-wideband characteristics.

Accordingly, the present invention has been made to overcome the disadvantages of the above-described technology, the object of the present invention is to implement an ultra-wideband wireless communication system for transmitting and receiving an ultra-wideband signal at a power of less than noise nanosecond (nano second) class It is to provide a baseband receiver of an ultra-wideband wireless communication system to enable a high-speed communication of Gbps because it uses a very short pulse of.

In order to achieve the above object, an embodiment of the present invention, in an ultra-wideband wireless communication system, is composed of X buffers and receives X-bit N-times data input from an analog / digital converter X times. An input buffer unit forming a; A pulse matching filter unit sampling the X × N bit data formed by the input buffer unit at a chip frequency using coefficients inputted from a coefficient unit; A cross correlator unit receiving a chip frequency sampled by the pulse matching filter unit, performing a despreading process through cross correlation operation using a spreading code, sampling at a symbol rate, and detecting a position at which a pulse exists; A peak detector for detecting a peak of the received data input from the cross correlator; A phase capture / tracker for acquiring and tracking the phase of the received data detected by the peak detector; A multiplexer for selecting one cross correlator among a plurality of cross correlators of the cross correlator portion and outputting a signal output from the selected cross correlator in response to an output signal of the phase acquisition / tracking portion; A multipath calculator for receiving a phase tracking signal through the multiplexer and generating phase shift and amplitude change information for a multipath; A conbiner for processing information about the phase shift and amplitude change of the multipath generated by the multipath calculator and a signal input through the multiplexer to be transmitted using a single antenna; And performing channel compensation on each path by using the information on the phase shift and the amplitude change of the multipath generated by the multipath calculator, and comparing the compensated result with a reference value to transmit the bits transmitted for each symbol clock. And a data reproducing unit for recovering the data.

Hereinafter, a baseband receiving apparatus of an ultra-wideband wireless communication system according to the present invention will be described with reference to the accompanying drawings.

It consists of 32 buffers and receives 32 times 8-bit data input from the analog / digital converter and forms 32 × 8-bit data, and 32 × formed by the input buffer unit 10. A pulse matching filter unit 20 for sampling 8-bit data at a chip frequency using coefficients input from the coefficient unit 100, and a chip frequency sampled by the pulse matching filter unit 20, and receiving a spreading code. The cross-correlator unit 30 performs a despreading process through cross-correlation operation using a spreading (PN) code input from the unit 110 to sample at a symbol rate and detect a position at which a pulse exists. A peak detector 40 for detecting peaks of the received data input from the base 30, a phase capture / tracker 50 for acquiring and tracking the phase of the received data detected from the peak detector 40, Prize A multiplexer 60 for selecting one cross correlator among a plurality of cross correlators of the cross correlator 30 in response to an output signal of the phase acquisition / tracking unit 50 and outputting a signal output from the selected cross correlator; The multipath calculator 70 receives a phase tracking signal through the multiplexer 60 and generates phase shift and amplitude change information for the multipath, and the multipath generated by the multipath calculator 70. Information about the phase shift and the amplitude change with respect to the multiplexer (60) and the conbiner (80) for processing to transmit the signal input through the multiplexer (60) and the multi-path calculator (70) By using the information on the phase shift and amplitude change of the multipath generated by the channel compensation for each path, and comparing the compensated result with the reference value symbol clock And a data reproducing unit 90 which restores the transmitted bits every time.

The input buffer unit 10 is composed of 32 input buffers. The data output from the analog / digital converter is stored in 32 input buffers, and each of them is superimposed by 15 to supply the 16 pulse matching filters to the pulse matching filter unit. .

The pulse matching filter unit 20 is a multiplier for multiplying 16 sample signals and 5 bit coefficients among 32 samples per window inputted from the input buffer unit, and an adder for adding a value outputted from the multiplier and a value fed back. And outputs sampling data using the signal output from the adder.

The cross correlator of the cross correlator 30 is in the form of an FIR filter, and a delay unit for sequentially delaying data input from the pulse matching circuit unit, a multiplier of the data inputted to each of the delay units, and a frame clock to despread the process. Let this be done.

The despreading process is at symbol rate.

The phase capture / tracker 50 detects a PN code after detecting a hopping sequence with respect to an arbitrary chip, and detects a sampling phase after detecting the PN code.

If the hopping sequence is not detected in the current chip, the phase acquisition / tracking unit 50 moves to another chip to detect the hopping sequence, and if the PN code is not detected in the current phase, the phase acquisition / tracking unit 50 moves the PN code. Search.

The phase capture / tracker 50 tracks and compensates a sampling time error due to a change in channel environment and a sampling clock difference between a transmitter and a receiver with respect to the acquired phase.

When the received signal moves to the boundary of the sampling window, the phase capturing / tracking unit 50 feeds back the control signal to the front end so that the sampling window moves in the opposite direction.

The FIR filter of the cross correlator updates the coefficient by the following grinding formula.

[Equation]

The multipath calculator 80 tracks the movement of the finger to adjust the multipath delay value so that the Prompt sample can maintain the peak of the chip pulse, while the multipath calculator 80 is updated. The multipath delay value is transmitted to the chip synchronization circuit.

The pulse matching filter of the pulse matching filter unit 20 uses the same coefficient value.

Referring to the operation of the baseband receiving apparatus of the ultra-wideband wireless communication system configured as described above are as follows.

First, the input data from the analog / digital converter is once stored in the input buffer unit 10 consisting of 32 input buffers, and then superimposed by 15 into the pulse matching filter unit 20 including 16 pulse matching filters (PMFs). Is output. The input buffer receives 32 times of 8-bit data from an analog / digital converter and forms 32 × 8 bit data.

The pulse matching filter (PMF) is a 5-bit coefficient input from the counter 100 using 16 samples out of 32 samples per window from an input buffer, and a multiplier 22 and an adder 23 shown in FIG. ) Repeats the calculation process consisting of multiplication and addition processes 16 times.

The calculation process is performed for every 16 pulse matching filters (PMFs) using adjacent samples, and the result is output to the despreader 24 of FIG. At this time, each pulse matching filter PMF uses the same count value, and all outputs are sampled at the chip frequency.

The cross-correlator 30 receives the output of each pulse matching filter (PMF) and performs a despreading process through cross-correlation using a spreading code.

The circuit structure of the cross-correlator 30 is in the form of an FIR filter and stores a pulse matched filter (PMF) output in a register for each frame clock according to time-hopping.

The cross-correlator 30 performs multiplication and addition operations using the 10 spreading codes input from the spreading code unit 110 and samples the result at a symbol rate.

The above operation is performed simultaneously on 16 cross-correlators receiving the pulse matching filter (PMF) outputs, and the cross correlator detects the position of the pulse using the pulse matching filter (PMF) output. .

In addition, the waveform shown in FIG. 4 is a result of cross-correlation between the pulse matched filter (PMF) output and the spreading code in each cross correlator when an input signal having a different phase is used. You can see that the value appears.

Meanwhile, the phase capture / tracker 50 receives 16 cross-correlator outputs through the peak detector 40 to acquire and track the phase of the received data.

The baseband receiving apparatus to which the present invention is applied operates in an acquisition mode or a tracking mode as shown in FIG. 5 according to the phase state. In other words, the acquisition mode is a process of detecting the phase of a received signal, using a combination of parallel search and serial search in consideration of hardware complexity and phase acquisition time. First, the hopping sequence is detected and then the PN code is detected. Finally, the sampling phase is detected.

If a hopping sequence is not detected on the current chip, it moves to another chip and continues searching. If the PN code is not detected in the current phase, the processor moves to another phase to continue searching for the PN code.

The tracking mode compensates for the acquired phase by continuously tracking the sampling time error caused by the change in the channel environment and the difference in the sampling clock between the transmitter and the receiver. If the received signal moves to the boundary of the sampling window, the control signal is fed back to the front end so that the sampling window moves in the opposite direction. Thus, the maximum signal is used when restoring data. At this time, the position tracking waveform is as shown in FIG.

The output of the cross-correlator 30 is output to the multipath calculator 80 and the data reproducing unit 90. That is, because UWB communication system uses ultra wideband pulses, there are many resolvable transmission paths, and in order to maximize SNR when reproducing data, energy scattered in each path must be collected, and fading phenomenon of reception pulses due to multipaths can be achieved. Is the amplitude and path delay of each finger. An adaptive filter is used to obtain the parameter, and the channel compensation value calculated for each Finger in the data reproducing unit 90 is multiplied. That is, the multipath calculator 70 delays the input signal by using the delay unit 71 as much as the maximum path delay to be considered, and then passes through the slicer 72 as shown in FIG. 7. The difference between the output of the adaptive filter 73 is calculated by using the adder 74, and the calculated result is used for the coefficient updating process. The multipath calculator 70 operates with a chip clock.

The adaptive filter 73 uses a simple LMS algorithm for updating the coefficients as the FIR filter structure. The main operation of this filter is expressed as an expression as follows.

[Equation]

In addition, the data reproducing unit 90 receives information such as phase shift and amplitude change for each of the multipaths obtained by the multipath calculator 70 through the combiner 80, and uses the inputted information. Channel compensation is performed for each path. That is, the data reproduction unit 90 compares the result value generated by performing the channel compensation with the reference value and restores the bits transmitted for each symbol clock. In addition, the data reproducing unit 90 always tracks the movement of the finger and adjusts the multipath delay value so that the prompt sample maintains the peak of the chip pulse. The updated delay value is transmitted to the chip synchronization circuit.

The present invention is not limited to the embodiments described above, and various modifications and changes can be made by those skilled in the art, which are included in the spirit and scope of the present invention as defined in the appended claims.

As described above, the baseband receiving apparatus of the ultra-wideband wireless communication system implemented by the present invention has an effect of solving the problem of frequency exhaustion when UWB technology for transmitting and receiving the ultra-wideband signal with less power than noise is developed. .

In addition, since the present invention uses a very short pulse of the nanosecond (nano second) class, there is an effect to implement a high-speed communication of the Gbps class.

In addition, since the present invention is transmitted and received in the form of a baseband signal, there is an effect that it is possible to simply implement the circuit and its structure of the transceiver device.

In addition, the present invention can solve the battery problem due to the low power consumption of less than a thousand compared to the existing communication equipment, there is an effect that can be miniaturized.

Claims (13)

In the ultra-wideband wireless communication system, An input buffer unit including X buffers and receiving N bit data input from an analog / digital converter X times to form X × N bit data; A pulse matching filter unit sampling the X × N bit data formed by the input buffer unit at a chip frequency using coefficients inputted from a coefficient unit; A cross correlator unit receiving a chip frequency sampled by the pulse matching filter unit, performing a despreading process through cross correlation operation using a spreading code, sampling at a symbol rate, and detecting a position at which a pulse exists; A peak detector for detecting a peak of the received data input from the cross correlator; A phase capture / tracker for acquiring and tracking the phase of the received data detected by the peak detector; A multiplexer for selecting one cross correlator among a plurality of cross correlators of the cross correlator portion and outputting a signal output from the selected cross correlator in response to an output signal of the phase acquisition / tracking portion; A multipath calculator for receiving a phase tracking signal through the multiplexer and generating phase shift and amplitude change information for a multipath; A conbiner for processing information about the phase shift and the amplitude change for the multipath generated by the multipath calculator and a signal input through the multiplexer to be transmitted using a single antenna; And The channel compensation is performed for each path by using the information on the phase shift and the amplitude change of the multipath generated by the multipath calculator, and the bits transmitted for each symbol clock are restored by comparing the compensated result with a reference value. A data reproducing unit; Baseband receiving device of the ultra-wideband wireless communication system, characterized in that comprises a. The method of claim 1, wherein the input buffer unit, Ultra wide band wireless communication comprising 32 input buffers, and storing the data output from the analog / digital converter in 32 input buffers, and then superimposing 15 data into 16 pulse matching filters of the pulse matching filter unit. Baseband receiver of the system. The method of claim 1, wherein the pulse matching filter unit, A multiplier for multiplying 16 sample signals and 5-bit coefficients out of 32 samples per window inputted from the input buffer unit, an adder for adding a value outputted from the multiplier and a feedback value, and a signal outputted from the adder Baseband receiving apparatus of the ultra-wideband wireless communication system, characterized in that for outputting the sampling data rule. The cross correlator of claim 1, wherein An ultra wideband radio having a FIR filter type, wherein a delay unit sequentially delaying data input from the pulse matching circuit unit and a data signal and a frame clock multiplied by the delay unit are multiplied to perform a despreading process. Baseband receiver for communication systems. The method of claim 4, wherein the despreading process, A baseband receiver of an ultra wideband wireless communication system, characterized in that the symbol rate is achieved. The method of claim 1, wherein the phase acquisition / tracking unit, A baseband receiver of an ultra-wideband wireless communication system, characterized by detecting a PN code after detecting a hopping sequence for an arbitrary chip, and detecting a sampling phase after detecting a PN code. The method of claim 6, wherein the phase acquisition / tracking unit, Ultra-wideband wireless communication, if the hopping sequence is not detected in the current chip to move to another chip to detect the hopping sequence, and if the PN code is not detected in the current phase to move to another phase to retrieve the PN code Baseband receiver of the system. The method of claim 7, wherein the phase acquisition / tracking unit, A baseband receiver of an ultra-wideband wireless communication system, characterized by tracking and compensating for sampling phase errors due to changes in channel environment and sampling clock differences between transmitters and receivers. The method of claim 8, wherein the phase acquisition / tracking unit, The baseband receiving apparatus of the ultra-wideband wireless communication system according to claim 1, wherein when the received signal moves to the boundary of the sampling window, the control signal is fed back to the front end so that the sampling window moves in the opposite direction. 5. The baseband receiver of an ultra wideband wireless communication system according to claim 4, wherein the FIR filter of the cross correlator updates coefficients by the following grinding formula. [Equation]

The multipath calculator of claim 1, wherein the multipath calculator comprises: A baseband receiver of an ultra-wideband wireless communication system, characterized in that it tracks the movement of a finger and adjusts the multipath delay value so that the Prompt sample maintains the peak of the chip pulse. The method of claim 11, wherein the multipath calculator, A baseband receiver of an ultra-wideband wireless communication system, wherein the updated multipath delay value is transmitted to a chip synchronization circuit. The pulse matching filter of claim 3, wherein the pulse matching filter comprises: A baseband receiver of an ultra wideband wireless communication system, characterized in that the same coefficient value is used.

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