JP4207590B2 - Receiving apparatus and synchronization processing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a receiving apparatus that receives a transmission signal composed of a pulse signal sequence, and a synchronization processing method that performs processing such as synchronization acquisition and synchronization maintenance of a received signal, and in particular, a received signal is multiplied by a template pulse, and the signal The present invention relates to a receiving apparatus that performs reception by passing through an integration or low-pass filter and a synchronization processing method.
[0002]
More specifically, the present invention relates to a receiving device of an ultra wide band (UWB) communication system that receives a signal sequence that constitutes an information signal using an impulse signal sequence having a very short period of about several hundred picoseconds. In particular, the present invention relates to a receiver and a synchronization processing method of an ultra-wide band communication system in which interference wave capability is enhanced in combination with DS-SS (direct spectrum spread).
[0003]
[Prior art]
As a system for releasing a user from a wired LAN connection, a wireless LAN has attracted attention. According to the wireless LAN, most of the wired cables can be omitted in a work space such as an office, so that a communication terminal such as a personal computer (PC) can be moved relatively easily. The demand for wireless LAN systems has increased significantly as the speed and price of wireless LAN systems have decreased. In particular, introduction of a personal area network (PAN) is being studied in order to establish a small-scale wireless network between a plurality of electronic devices existing around a person and perform information communication.
[0004]
Recently, a wireless local area network (LAN) system using an SS (Spread Spectrum) system has been put into practical use. The DS (Direct Spread) system, which is a type of SS system, spreads the occupied band by multiplying the information signal by a random code sequence called a PN (Pseudo Noise) code on the transmission side and transmits it. On the receiving side, the received spread information signal is despread by multiplying the received spread information signal by the PN code to reproduce the information signal.
[0005]
Furthermore, a UWB (Ultra Wide Band) transmission method using the SS method has been proposed for applications such as PAN. As a UWB transmission method, a method of performing wireless communication by placing information on a very weak impulse train is attracting attention as a wireless communication system that realizes short-range ultrahigh-speed transmission, and its practical application is expected (for example, non-patent) (Ref. 1).
[0006]
In the UWB transmission system, an information signal is configured by using a DS-UWB system in which the spreading speed of a DS information signal is increased to the limit, and an impulse signal sequence having a very short period of about several hundred picoseconds. There are two types of impulse-UWB systems that transmit and receive columns.
[0007]
In the DS-UWB system, the spectrum can be controlled by the PN code speed, but there is a problem that power consumption tends to increase because the logic circuit needs to operate at a high speed of the order of GHz. On the other hand, the impulse-UWB system can be configured by a combination of a pulse generator and a low-speed logic circuit, so that there is a merit that current consumption can be reduced, but there is a problem that it is difficult to control the spectrum with the pulse generator.
[0008]
In addition, both systems realize high-speed data transmission by performing transmission / reception by spreading in an ultra-high frequency band of 3 GHz to 10 GHz, for example. The occupied bandwidth is a bandwidth on the order of GHz such that a value obtained by dividing the occupied bandwidth by its center frequency (for example, 1 GHz to 10 GHz) is approximately 1, and is a so-called W-CDMA, cdma2000 system, and SS (Spread Spectrum). ) And a bandwidth that is normally used in a wireless LAN using an OFDM (Orthogonal Frequency Division Multiplexing) method, the bandwidth is extremely wide.
[0009]
In February 2002, the US FCC relaxed regulations on the UWB system. As the contents of the deregulation, it is permitted to emit radio waves with an output of −41.3 dBm from 3.1 GHz to 10.6 GHz. In the standardization work of IEEE 802.15.3, for example, a method of performing communication by forming a piconet between wireless communication apparatuses that perform UWB wireless communication is being standardized.
[0010]
The transmitter side of UWB communication modulates (multiplies) the PN-spread transmission signal with a pulse signal having a predetermined pulse width, amplifies the transmission signal as an impulse signal sequence with a power amplifier, and uses a bandpass filter. Only the signal component of the frequency that complies with regulations such as FCC is extracted and sent out from the antenna to the transmission line.
[0011]
On the other hand, received data can be obtained by PN despreading, but for this purpose, it is necessary to obtain synchronization of the received signal. The acquisition of synchronization here means both synchronization of pulse position and synchronization of code phase, and processing time is required.
[0012]
In the conventional UWB transmission system, reception processing is performed by multiplying a received signal by a template pulse and passing the signal through an integration or low-pass filter (LPF).
[0013]
FIG. 8 shows the configuration of a UWB transceiver using conventional sliding correlation. FIG. 9 shows the internal configuration of the baseband circuit in the UWB transceiver shown in FIG. However, in the example shown in the figure, a BPSK (Binary Phase Shift Keying) modulation method is applied, and transmission data is carried only by the I-axis signal, and the Q-axis signal is not used for data transmission.
[0014]
First, the transmission operation will be described. The transmission data is multiplied (modulated) with the spreading code in the baseband circuit. Further, a higher oscillation frequency is obtained by multiplying an oscillation frequency output from a crystal oscillator (VCTCXO) or the like using a PLL and a VCO. The pulse generator generates a pulse signal using this oscillation frequency. The PN-spread transmission signal is modulated (multiplied) with a pulse signal having a predetermined pulse width, the transmission signal that has become an impulse signal sequence is amplified by a power amplifier (PA), and then a bandpass filter (BPF). Only the signal component of the frequency that complies with regulations such as FCC is extracted and sent out from the antenna to the transmission line.
[0015]
When transmitting, set the VCO oscillation frequency to f _c Send as. Where f _c Indicates the chip rate of the pulse.
[0016]
On the other hand, at the time of reception, the signal received by the antenna passes through a bandpass filter (BPF), and frequency components other than the transmission pulse signal component are removed. The signal that has passed through the bandpass filter is further amplified by a low noise amplifier (LNA). In addition, the oscillation frequency output from a crystal oscillator (VCTCXO) or the like is multiplied by using a PLL and a VCO to obtain a template pulse by a pulse generator using the same frequency as that at the time of transmission, and the other pulse generator A template pulse whose phase is shifted by 90 degrees is obtained by quadrature modulation. These are multiplied by the received signal in each multiplier to obtain detection signals for the I axis and the Q axis, respectively. Further, these detection signals are applied to a low-pass filter (LPF) to remove high-frequency components, A / D conversion is performed at the peak of the pulse after the filtering, and digital processing is performed in the baseband circuit.
[0017]
In the baseband circuit, each I-axis and Q-axis detection signal is multiplied by a spreading code to be despread, and the despread signal is integrated in an integration dump. The I-axis signal is subjected to FEC (Forward Error Correction) and CRC (Cyclic Redundancy Check code), and the received data is extracted. The Q-axis signal is fed back to the clock generator through a loop filter. The clock generator adjusts the clock generation timing according to the integration output.
[0018]
In the example shown in FIG. 8, a variable frequency oscillator such as a VCTCXO (Voltage Controlled Temperature Compensated Crystal Oscillator) is used as an oscillator serving as a reference for the clock frequency. The VCTCXO can set the oscillation frequency according to the input voltage, and the oscillation frequency is determined according to the phase control signal supplied from the baseband circuit.
[0019]
First, at the time of synchronization acquisition, a phase control signal for synchronization acquisition is supplied from the baseband circuit, and the oscillation frequency of the VCO is f = f _c The template pulse is generated at a frequency higher by Δf than the chip rate so as to be + Δf.
[0020]
In addition, after synchronization is acquired, synchronization is maintained by adjusting the oscillation frequency based on a phase control signal (error signal) that is an integrated output of the Q-axis signal fed back from the baseband circuit.
[0021]
FIG. 10A shows a received pulse waveform, and FIG. 10B shows a received template waveform. As shown in FIG. 10B, the reception-side template waveform is made shorter than the pulse interval T1 at which the pulse interval T2 is transmitted. Such a deviation is not so large when viewed in the received pulse period T1, but becomes larger due to a series of pulses, and is the least common multiple of T1 and T2, that is, T1 × k1 = T2 × (k1 + 1). At the number of pulses k1, the received signal and the received template waveform pulse are shifted by one.
[0022]
This means that the phase of the spread code of the received template waveform is shifted by one with respect to the transmission signal, and by “sliding correlation” the section where the pulse shift occurs by the number of code lengths of the spread code, The phase of the spread code of the transmission signal can be found.
[0023]
In the synchronization acquisition process using such a conventional sliding correlation method, first of all, there is a problem that synchronization takes a very long time. When Δf is set large, the synchronization acquisition time is shortened, but the frequency f _c + Δf and f after synchronization is acquired (ie, when synchronization is maintained) _c Therefore, there is a problem that the response becomes slow. Furthermore, since a variable frequency oscillator such as VCTCXO is required to slide the reception template waveform, there is a problem that the component configuration becomes complicated.
[0024]
[Non-Patent Document 1]
Nikkei Electronics, March 11, 2002 issue “Ultra Wideband, a wireless revolutionary child that raises birth” 55-66
[0025]
[Problems to be solved by the invention]
An object of the present invention is to provide an excellent receiving apparatus and synchronization processing method capable of suitably receiving by multiplying a received signal by a template pulse and passing the signal through an integration or low-pass filter. is there.
[0026]
A further object of the present invention is to multiply a received signal by a template pulse and integrate or low-pass the received signal in an ultra-wide band communication system in which interference wave capability is enhanced in combination with DS-SS (direct spread spectrum). An object of the present invention is to provide an excellent receiving apparatus and synchronization processing method that can perform reception suitably by passing through a filter.
[0027]
It is a further object of the present invention to provide an excellent receiving apparatus and synchronization processing method capable of acquiring synchronization in a short time with a relatively simple component configuration without using a frequency variable type oscillator such as VCTCXO. .
[0028]
[Means and Actions for Solving the Problems]
The present invention has been made in consideration of the above problems, and is a receiving device that receives a transmission signal composed of a pulse signal sequence,
Receiving means for receiving a transmission signal;
Pulse generating means for generating a template pulse having a pulse generation interval substantially the same as the transmission signal;
Phase shift means for shifting the generation timing of the template pulse generated by the pulse generation means at a predetermined interval;
Correlation means for correlating each template pulse whose generation timing is shifted by the phase shift means and the received pulse received by the receiving means;
Synchronization acquisition means for acquiring synchronization of a received signal based on a correlation result by the correlation means;
It is a receiver characterized by comprising.
[0029]
The receiving apparatus according to the present invention receives, for example, a signal sequence that constitutes an information signal by using an impulse signal sequence having a very short period of about several hundred picoseconds by an ultra-wide band communication system. . For example, by combining with DS-SS (direct spectrum spread), the ability to withstand interference waves can be enhanced.
[0030]
The pulse generation means can be composed of an oscillator that outputs a clock signal having a fixed frequency, and a PLL and a VCO that multiply the clock signal.
[0031]
In the present invention, the sliding correlation is performed by using the phase shift means and shifting the generation timing instead of the reception template pulse generation interval.
[0032]
The phase shift means can control the clock generation timing based on the control signal, but does not control the clock generation interval (frequency). The phase shift means has a chip interval T _c Is divided into M equal parts, and Δt (= T per time) _c / M) The template pulse generation timing is shifted by one, and M timing shifts are performed for each code phase. The correlation means performs M × K correlation receptions (where K is the code length). Thus, it is considered that the synchronization acquisition means can synchronize the received signal.
[0033]
The timing shift count M of the phase shift means corresponds to the resolution of the timing search. If the timing shift number M is large, more accurate synchronization acquisition can be performed. However, the synchronization acquisition time becomes longer by that amount, and a longer preamble must be transmitted from the transmitter side. Conversely, if M is small, the accuracy of synchronization acquisition is low, but the time required for synchronization acquisition is short, and a short preamble may be transmitted from the transmitter.
[0034]
The number of times of timing shift M is not determined and set arbitrarily on the receiver side, but requires a mechanism for performing a predetermined negotiation between the transmitter and the receiver and notifying each other together with a necessary preamble length.
[0035]
In addition, the receiver according to the present invention, after acquiring the synchronization, multiplies the received signal by a template pulse and passes the signal through an integration or low-pass filter, and the timing of the phase shift means is obtained. -The shift amount should be adjusted to maintain synchronization.
[0036]
In the conventional sliding correlation method, the error signal is D / A converted and the oscillation frequency of the VCTCXO is voltage-controlled to maintain the synchronization. In this case, since an analog loop for controlling the oscillation frequency is used, the circuit configuration is complicated.
[0037]
On the other hand, in the sliding correlation method according to the present invention, synchronization is maintained by adjusting the timing shift amount of the phase shift means based on the error signal. At this time, it is not necessary to directly control the frequency of the oscillator, as in the case of synchronization acquisition, and the apparatus configuration is simplified. Therefore, an oscillator that outputs a fixed frequency, such as TCXO, can be used instead of a frequency variable oscillator such as VCTCXO.
[0038]
Other objects, features, and advantages of the present invention will become apparent from more detailed description based on embodiments of the present invention described later and the accompanying drawings.
[0039]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0040]
FIG. 1 shows the configuration of a UWB transceiver according to an embodiment of the present invention. FIG. 2 shows the internal configuration of the baseband circuit in the UWB transceiver shown in FIG. However, in the example shown in the figure, a BPSK (Binary Phase Shift Keying) modulation method is applied, and transmission data is conveyed only on the I axis. Further, as will be described later, sliding correlation is performed to acquire synchronization.
[0041]
First, the transmission operation will be described. The transmission data is multiplied (modulated) with a spreading code by a multiplier 153 in the baseband circuit 150 to obtain spread transmission data. Further, the oscillation frequency output from the crystal oscillator (TCXO) 108 or the like is multiplied by using the PLL 107 and the VCO 106 to obtain a higher oscillation frequency. The pulse generator 109 generates a pulse signal using this oscillation frequency. The PN-spread transmission signal is modulated (multiplied) by a multiplier 105 with a pulse signal having a predetermined pulse width, and the transmission signal that has become an impulse signal sequence is amplified by a power amplifier (PA) 104, The filter (BPF) 102 extracts only a signal component having a frequency that conforms to regulations such as FCC, and sends it out from the antenna 101 to the transmission line.
[0042]
On the other hand, at the time of reception, the signal received by the antenna 101 passes through the bandpass filter 102 and the frequency components other than the transmission pulse signal component are removed. The signal that has passed through the bandpass filter 102 is further amplified by a low noise amplifier 110. Further, the oscillation frequency output from the crystal oscillator (TCXO) 108 is multiplied by using the PLL 107 and the VCO 106 to obtain a template pulse by the pulse generator 109 using the same frequency as that at the time of transmission, and the other pulse generator At 112, a quadrature modulator 111 obtains a template pulse whose phase is shifted by 90 degrees. These are multiplied by the received signals in multipliers 113 and 114, respectively, to obtain I-axis and Q-axis detection signals. Further, these detection signals are applied to low-pass filters (LPF) 115 and 116, respectively, to remove high-frequency components, and at the peak of the pulse after the filtering, A / D conversions 117 and 118 convert them to digital signals. Digital processing is performed in the band circuit 150.
[0043]
In the baseband circuit 150, each of the I-axis and Q-axis detection signals is multiplied by a spreading code by multipliers 151 and 152, respectively, and despreading is performed, and integration dumps 154 and 155 integrate the despread signals. The I-axis signal is subjected to FEC (Forward Error Correction) 156 and CRC (Cyclic Redundancy Check code) 157, and the received data is extracted. Further, the Q-axis signal is fed back to the clock generator via the loop filter 158. The clock generator adjusts the clock generation timing according to the integration output.
[0044]
In this embodiment, as shown in FIG. 1, instead of a frequency variable type oscillator such as VCTCXO, an oscillator that oscillates only a fixed frequency such as TCXO 108 is used, and an analog loop for controlling the oscillation frequency is deleted. It has a simple component structure.
[0045]
Further, in the present embodiment, the sliding correlation is performed by using the phase shifter circuit 119 and shifting the generation timing instead of the reception template pulse generation interval. The phase shifter circuit 119 here means a circuit that can control the clock generation timing by a control signal, and does not control the clock generation interval (frequency).
[0046]
FIG. 3 shows an output example of the phase shifter circuit according to the present embodiment. In the figure, the phase shifter circuit 119 has a period of one cycle (chip interval T _c ) Is divided into four equal parts, and the four generation signals from phase # 1 to phase # 4 having the same generation interval but with the generation timing shifted by a quarter of one cycle can be output. The phase shifter circuit 119 can selectively output signals from the phase # 1 to the phase # 4 by the control signal supplied from the baseband circuit 150.
[0047]
In the UWB transceiver according to this embodiment, an oscillator that oscillates only a fixed frequency such as the TCXO 108 is used, and this is further multiplied using the PLL 107 and the VCO 106 to obtain a high-frequency clock frequency. The phase shifter circuit 119 shown in FIG. 3 controls the generation timing, not the clock frequency.
[0048]
In the conventional sliding correlation method shown in FIGS. 8 and 9, a relationship of T2 <T1 is given between the pulse interval T1 of the received signal and the pulse interval T2 of the received template waveform (see FIG. 10). . On the other hand, in the sliding correlation method according to this embodiment, T2 = T1. Controlling the pulse generation timing means that the received signal is equivalently oversampled.
[0049]
In the conventional sliding correlation method, since T2 <T1, the number of pulses of the received template signal is one surplus compared to the received signal in the number of pulses k1 where T1 × k1 = T2 × (k1 + 1). The phase will be shifted automatically (see FIG. 10).
[0050]
On the other hand, in the sliding correlation method according to the present embodiment, since the pulse generation timing is shifted, the code phase of the receiving template signal does not have a code phase shift with respect to the received signal. Therefore, as shown in FIG. 2, at the time of synchronization acquisition, a synchronization acquisition logic circuit 159 for supplying a control signal for controlling the phase of the generated code to the code generator on the receiving side is required.
[0051]
The synchronization acquisition logic circuit 159 outputs a phase control signal (code phase control signal) to the phase shifter circuit 119 so as to generate a signal whose timing is shifted from phase # 1 to phase # 4 at the time of synchronization acquisition. (Described later).
[0052]
Further, after the synchronization is acquired, the synchronization shift is maintained by adjusting the timing shift amount of the phase shifter circuit 119 based on the phase control signal (error signal) composed of the integrated output of the Q-axis signal fed back from the baseband circuit 150. Is done.
[0053]
FIG. 4 shows the state of pulses in the sliding correlation method according to the present embodiment. In this embodiment, since the generation timing of the reception template signal is shifted, in the example shown in the figure, there is a time difference of Δt with respect to the reception signal, and it can be seen that the pulse interval is equal between the reception signal and the reception template signal. This time difference Δt is given by the phase shifter circuit 119 based on the phase control signal from the baseband circuit 159.
[0054]
In the UWB transmission / reception system according to the present embodiment, a preamble part (training signal) for pulse detection and channel estimation is included at the head of the transmission signal. FIG. 5 shows the configuration of the preamble section according to this embodiment. One block shown in the upper part of the figure shows one symbol spread by one spreading code. In the figure, all symbols are 1.
[0055]
Here, K is the length of the spreading code, and M is the number of timing shifts. The phase shifter circuit 119 divides the period of one cycle (chip interval) into M equal parts, and the generation interval is the same, but the generation timing is deviated by 1 / M of one cycle (in the example shown in FIG. 3). The signal of M = 4) is output. The timing shift number M corresponds to the resolution of the timing search by the phase shifter circuit 119.
[0056]
When the transmitter / receiver shown in FIG. 1 receives the preamble and performs synchronization, correlation reception is performed while shifting the generation timing of the received signal by a phase shifter circuit using a certain spreading code.
[0057]
In the example shown in FIG. 5, M timing shifts are performed for one code phase. Therefore, the shift amount Δt per time is Δt = T _c / M (T _c : Chip interval). After performing a timing search for a certain code phase, the phase shifter circuit shifts the generated code of the code generator for the reception template by one by the code phase control signal output from the synchronization acquisition logic circuit 159 shown in FIG. Also, M timing shifts are performed.
[0058]
In the example shown in FIG. 5, the code length is K, and it is considered that the received signals can be synchronized by performing M × K correlation receptions in total.
[0059]
6 and 7 show how correlation reception is performed by the sliding correlation method according to the present embodiment.
[0060]
FIG. 6 shows the output value of the integral dump circuit when the signal is transmitted, and FIG. 7 shows the output value of the integral dump circuit when the signal is not transmitted. From each figure, it can be seen that synchronization can be obtained by using the sliding correlation method according to the present embodiment.
[0061]
After the synchronization is obtained by the timing shift of the received template pulse using the phase shifter circuit 119, the synchronization is maintained.
[0062]
In the conventional sliding correlation method, the error signal is D / A converted and the oscillation frequency of the VCTCXO is voltage-controlled to maintain the synchronization. In this case, since an analog loop for controlling the oscillation frequency is used, the circuit configuration is complicated.
[0063]
On the other hand, in the sliding correlation method according to the present embodiment, synchronization is maintained by adjusting the timing shift amount of the phase shifter circuit 119 based on the error signal. At this time, it is not necessary to directly control the frequency of the oscillator 108 as in the case of synchronization acquisition, and the apparatus configuration is simplified. As shown, an oscillator that outputs a fixed frequency such as TCXO can be used.
[0064]
As described above, the timing shift number M of the phase shifter circuit 119 corresponds to the resolution of timing search, and the period of one cycle is divided equally into M and the generation interval is the same, but the generation timing is M minutes. M signals shifted by 1 (M = 4 in the example shown in FIG. 3) are output. The synchronization of the received signal is obtained by performing M × K correlation receptions in total.
[0065]
If the timing shift number M is large, more accurate synchronization acquisition can be performed. However, the synchronization acquisition time becomes longer by that amount, and a longer preamble must be transmitted from the transmitter side. Conversely, if M is small, the accuracy of synchronization acquisition is low, but the time required for synchronization acquisition is short, and a short preamble may be transmitted from the transmitter.
[0066]
The number of times of timing shift M is not determined and set arbitrarily on the receiver side, but requires a mechanism for performing a predetermined negotiation between the transmitter and the receiver and notifying each other together with a necessary preamble length.
[0067]
[Supplement]
The present invention has been described in detail above with reference to specific embodiments. However, it is obvious that those skilled in the art can make modifications and substitutions of the embodiment without departing from the gist of the present invention. That is, the present invention has been disclosed in the form of exemplification, and the contents described in the present specification should not be interpreted in a limited manner. In order to determine the gist of the present invention, the claims section described at the beginning should be considered.
[0068]
【The invention's effect】
As described above in detail, according to the present invention, in the ultra-wide band communication system in which interference wave capability is enhanced in combination with DS-SS (direct spectrum spread), a received signal is multiplied by a template pulse, It is possible to provide an excellent receiving apparatus and synchronization processing method capable of preferably performing reception by passing the signal through an integration or low-pass filter.
[0069]
Further, according to the present invention, it is possible to provide an excellent receiving apparatus and synchronization processing method capable of acquiring synchronization in a short time with a relatively simple component configuration without using a frequency variable type oscillator such as a VCTCXO. it can.
[0070]
According to the present invention, in the synchronization acquisition process on the receiver side in the UWB transmission method, it is not necessary to control the frequency of the frequency variable type oscillator such as the VCTCXO by the analog loop, and the frequency fixed type type such as the TCXO. Using an oscillator and a phase shifter circuit, sliding correlation can be performed with a simple component configuration.
[0071]
In the conventional sliding correlation method, since the oscillation frequency of the VCTCXO is controlled, the response from the synchronization acquisition to the reception frequency is a problem (f _c + Δf → f _c ). On the other hand, in the sliding system according to the present invention, synchronization is acquired without frequency shift by the TCXO and the phase shifter circuit, so that the response problem at the time of synchronization acquisition is alleviated.
[0072]
Further, in the conventional sliding correlation method, Δf _c Can not be taken too large. On the other hand, in the proposed method, the timing resolution M can be adjusted within a range where synchronization can be achieved. Δf _c When determining the value, it is necessary to consider the trade-off between synchronization accuracy and transient response. On the other hand, the timing resolution M of the phase shifter circuit need only consider the synchronization accuracy.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a UWB transceiver according to an embodiment of the present invention.
FIG. 2 is a diagram showing an internal configuration of a baseband circuit in the UWB transceiver shown in FIG.
FIG. 3 is a diagram illustrating an output example of a phase shifter circuit according to an embodiment of the present invention.
FIG. 4 is a view showing a state of a pulse in the sliding correlation method according to an embodiment of the present invention.
FIG. 5 is a diagram showing a configuration of a preamble part.
FIG. 6 is a diagram illustrating a state in which correlation reception is performed by the sliding correlation method according to the present invention.
FIG. 7 is a diagram illustrating a state in which correlation reception is performed by the sliding correlation method according to the present invention.
FIG. 8 is a diagram illustrating a configuration of a conventional UWB transceiver using sliding correlation.
9 is a diagram showing an internal configuration of a baseband circuit in the UWB transceiver shown in FIG.
FIG. 10 is a diagram for explaining the operation of a conventional sliding correlation method;
[Explanation of symbols]
101 ... antenna
102: Band pass filter (BPF)
103 ... duplexer (SW)
104 ... Power amplifier (PA)
105 ... Multiplier
106 ... VCO
107 ... PLL
108 ... TCXO
109: Pulse generator
110 ... Low noise amplifier (LNA)
111 ... Quadrature modulator
112 ... Pulse generator
115, 116 ... low-pass filter
117, 118 ... A / D converter
119: Phase shifter circuit
150 ... Baseband circuit
151, 152, 153... Multipliers
154,155 ... Integral dump
156 ... FEC
157 ... CRC
158 ... Loop filter
159 ... logic circuit for acquiring synchronization

Claims (10)

A receiving device for receiving a transmission signal composed of a pulse signal sequence multiplied by a spreading code ,
Receiving means for receiving a transmission signal;
And pulse generating means for generating a transmission signal and a second template pulses only phase shift first template pulse及beauty 90deg which substantially consists of the same pulse generation interval,
Phase shift means for shifting the generation timings of the first and second template pulses generated by the pulse generation means at predetermined intervals, respectively ;
First and second multipliers for multiplying the received signal by the first and second template pulses, respectively, to obtain I-axis and Q-axis detection signals;
Third and fourth multipliers for performing despreading by multiplying the detection signals of the I axis and Q axis by the spreading code, respectively;
Received data processing means for integrating the I-axis despread signal to extract received data;
Synchronization processing means for adjusting the generation timing of the template pulse by the phase shift means based on a correlation reception result obtained by integrating the despread signal on the Q axis;
Equipped with,
The synchronization processing means acquires the synchronization of the received signal based on each correlation reception result when the timing of generating the first and second template pulses is sequentially shifted by the phase shift means at predetermined intervals. ,
A receiving apparatus. Receives a signal train of the ultra-wide band communication method combined with DS-SS.
The receiving apparatus according to claim 1. The pulse generation means includes an oscillator that outputs a clock signal having a fixed frequency, and a PLL and a VCO that multiply the clock signal.
The receiving apparatus according to claim 1. The synchronization processing means divides the chip interval T _c into M equal parts by the phase shift means and obtains the generation timing of template pulses by Δt (= T _c / M) per time when the synchronization of the received signal is acquired. Shift, perform M timing shifts for each code phase, and perform M × K correlation reception (where K is the code length),
The receiving apparatus according to claim 1. A means for determining the number M of timing shifts by negotiation with the transmitter side;
The receiving apparatus according to claim 1. The synchronization processing means adjusts the shift amount of the generation timing of the first and second template pulses based on an error signal obtained by integrating the despread signal of the Q axis after acquiring synchronization. Keep sync,
The receiving apparatus according to claim 1. A synchronization processing method for performing synchronization processing by sliding correlation of a received pulse multiplied by a spreading code and a template pulse,
A pulse generation step of generating a received pulse and the second template pulses only phase shift first template pulse及beauty 90deg which substantially consists of the same pulse generation interval,
A detection step of multiplying the received signal by the first and second template pulses, respectively, to obtain a detection signal for each of the I axis and the Q axis;
A despreading step of performing despreading by multiplying each of the I-axis and Q-axis detection signals by the spreading code;
The first and second template pulses are generated based on each correlation reception result obtained by integrating the despread signal of the Q axis while sequentially shifting the generation timing of the second template pulse at predetermined intervals. A synchronization processing step for adjusting the occurrence timing of
A synchronization processing method comprising: In the synchronization processing step, the chip interval T _c is equally divided into M, the template pulse generation timing is shifted by Δt (= T _c / M) per time, and M times of timing for each code phase are obtained. Shift and perform M × K correlation reception (where K is the code length),
The synchronization processing method according to claim 7. A synchronization that maintains synchronization by adjusting the shift amount of the generation timing of the first and second template pulses on the basis of an error signal obtained by integrating the inversely expanded signal of the Q-axis after acquiring the synchronization. Further comprising a holding step;
The synchronization processing method according to claim 7. A receiving device for receiving a transmission signal transmitted using a wideband,
Receiving means for receiving a transmission signal;
An oscillator that oscillates a fixed frequency;
Carrier generation means for generating a carrier by multiplying the oscillation frequency output from the oscillator;
Phase shift means for shifting the generation timing of the carrier wave at predetermined intervals;
Pulse generating means for generating a first template pulse having a pulse generation interval substantially the same as a transmission signal and a second template pulse having a phase shift of 90 deg using a carrier wave whose generation timing is shifted;
First and second multipliers for multiplying the received signal by the first and second template pulses, respectively, to obtain I-axis and Q-axis detection signals;
Third and fourth multipliers for performing despreading by multiplying the detection signals of the I axis and Q axis by the spreading code, respectively;
Received data processing means for integrating the I-axis despread signal to extract received data;
Synchronization processing means for adjusting the generation timing of the template pulse by the phase shift means based on a correlation reception result obtained by integrating the despread signal on the Q axis;
Equipped with,
The synchronization processing means acquires the synchronization of the received signal based on each correlation reception result when the timing of generating the first and second template pulses is sequentially shifted by the phase shift means at predetermined intervals. ,
A receiving apparatus.

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