JPH11261662A - Information processing device and method and supply medium thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To establish carrier reproduction with higher accuracy and to establish the receiving synchronization with higher assurance. SOLUTION: A carrier reproduction part 35 performs carrier reproduction by the use of the receiving signal corresponding to a unique word (w2), and the reproduced carrier is multiplied by the receiving signal corresponding to the word (w2) delayed by a delay part 31 and the receiving signal corresponding to a unique word (w1) delayed by a delay part 42 by the multiplication parts 36 and 43 respectively. In other words, the frequencies of both words (w1) and (w2) are corrected into their original frequencies. A carrier reproduction part 47 performs the carrier reproduction by the use of the receiving signal corresponding to the word (w1) having its corrected frequency. A multiplication part 49 multiplies the receiving signal of the word (w1) having its corrected frequency by the reproduced carrier to correct the phase of the word (w1).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information processing apparatus and method, and a providing medium. More particularly, the present invention relates to a more accurate carrier reproduction using a unique word arranged in a synchronous burst signal. The present invention relates to an information processing apparatus and method, and a providing medium that can more reliably establish reception synchronization.

[0002]

2. Description of the Related Art Communication satellites (hereinafter referred to as CS)
A variety of services have been started in digital multi-channel broadcasting using (described as). In addition, broadcast satellites (hereinafter,
B), which is scheduled to be launched in the future
It has been reported by the Radio Control Council that digital broadcasting services will be provided by S4 latecomers.

[0003] As a satellite communication system using BS or CS, for example, time division multiple access (TDMA) is used.
n Multiple Access) system is known. In the TDMA system, a transmission signal is configured in a frame unit of a predetermined cycle,
Further, each frame is divided into a plurality of time slots called bursts, and these signals are called burst signals.

The burst signal includes a data burst signal and a synchronous burst signal (reference burst signal). The role of the synchronous burst signal is mainly to provide a time reference for the data burst to each station accessing the network. Generally, a carrier (carrier) recovery code (Carrier Recovery), a clock recovery code (Symbol Timing Recovery), a unique word (Unique Word), and the like are arranged in the reference burst signal. On the receiving side, using the carrier recovery code and the clock recovery code,
By performing carrier recovery and clock recovery and detecting a unique word, a time reference for a received frame can be obtained.

As such a synchronous burst signal, FIG.
A configuration as shown in FIG. This synchronization burst signal is the first one of a total of 96 bits.
6 bits (TAB1) and last 16 bits (TAB2)
, A unique word W1 and a unique word W2 (or W3) are arranged as shown in FIG. Of the superframe composed of eight frames, the unique word W2 is arranged only in TAB2 of the synchronization burst signal included in the first frame,
A unique word W3 having an inversion relationship with the unique word W2 is arranged in TAB2 of the synchronous burst signal of the remaining seven frames. The 64-bit data includes, for example, TM which is transmission information such as a modulation scheme and a coding rate.
CC (Transmission Multiplexing Configuration Control)
l) is arranged.

In this example, the value (1B95) is used as the unique word W1, the value (A340) is used as the unique word W2, and the value (5C) is used as the unique word W3.
BF) are respectively set (all in hexadecimal notation). FIG. 6C shows the synchronous burst signal after the convolutional code processing of the code rate 1/2 has been performed. However, the first four bits are the last four bits of the burst signal of the preceding stage. The synchronous burst signal excluding the 4 bits is convolutionally coded to be a signal of 192 bits in total. Of these, the first 12 bits of each of the portions (32 bits) corresponding to the unique word W1 and the unique word W2 (W3) are coded together with the preceding bits at the time of the convolutional code, and thus are used as unique words. Can not do. Therefore, the remaining 20 bits are used as the unique word.
Note that the first bit of the unique word w1 and the first bit of the unique word w2 (or w3) are 160
Bits are separated.

[0007]

Conventionally, when carrier synchronization and clock synchronization are performed using a carrier recovery code and a clock recovery code, or carrier synchronization and clock synchronization are performed using a synchronization burst signal shown in FIG. If so, carrier reproduction and clock reproduction must be completed just before the unique word. However, when the processing speed of reproduction is increased, phase jitter increases, and conversely, when the processing speed is reduced, synchronization cannot be obtained.

Further, a method of performing carrier recovery and clock recovery by receiving and storing all of the synchronous burst signals shown in FIG. 6 can be considered. In this case, however, a storage unit such as a memory is required. In addition, there is a problem that a longer processing time is required.

The present invention has been made in view of such a situation, and it is possible to perform carrier reproduction with higher accuracy by using a plurality of unique words, and thereby to establish reception synchronization more reliably. To make it possible.

[0010]

An information processing apparatus according to claim 1 comprises: first carrier reproducing means for reproducing a carrier using a frequency of a first received signal corresponding to a second unique word; First correcting means for correcting the frequency of the first received signal and the frequency of the second received signal corresponding to the second unique word using the carrier reproduced by the first reproducing means; The second carrier regenerating means for regenerating a carrier using the first received signal the frequency of which is corrected by the first correcting means, and the frequency is corrected using the carrier reproduced by the second carrier regenerating means. A second correction unit for correcting the phase of the first reception signal.

According to a third aspect of the present invention, there is provided an information processing method comprising: a first carrier reproducing step of reproducing a carrier using a frequency of a first received signal corresponding to a second unique word; A first correcting step of correcting the frequency of the first received signal and the frequency of the second received signal corresponding to the second unique word using the reproduced carrier; A second carrier regeneration step of regenerating a carrier using the first received signal whose frequency has been corrected, and a first frequency of the first received signal whose frequency has been corrected using the carrier reproduced in the second carrier reproduction step. And a second correction step of correcting the phase.

According to a fourth aspect of the present invention, there is provided the medium, wherein the carrier is reproduced using a frequency of the first received signal corresponding to the second unique word, and the carrier is reproduced in the first reproducing step. A first correction step for correcting the frequency of the first received signal and the frequency of the second received signal corresponding to the second unique word using the obtained carrier; A second carrier regenerating step for regenerating a carrier using the corrected first received signal, and a phase of the frequency-corrected first received signal using the carrier regenerated in the second carrier regenerating step And a second correction step of correcting the following.

[0013] The information processing apparatus according to claim 1, and claim 3.
In the information processing method according to the aspect, the carrier is reproduced using the frequency of the first reception signal corresponding to the second unique word, and the first carrier is reproduced using the carrier. The frequency of the received signal and the frequency of the second received signal corresponding to the second unique word are corrected. In addition, a carrier is reproduced using the first reception signal whose frequency has been corrected, and the phase of the first reception signal whose frequency has been corrected is corrected using the carrier.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below. In order to clarify the correspondence between each means of the invention described in the claims and the following embodiments, each means is described. When the features of the present invention are described by adding the corresponding embodiment (however, an example) in parentheses after the parentheses, the result is as follows. However, of course, this description does not mean that each means is limited to those described.

[0015] The information processing apparatus according to the first aspect of the present invention provides a first carrier reproducing means (for example, a carrier reproducing section 35 shown in the figure) for reproducing a carrier using a frequency of a first received signal corresponding to a second unique word. ) And first correction means for correcting the frequency of the first received signal and the frequency of the second received signal corresponding to the second unique word using the carrier reproduced by the first reproducing means. (For example, the multiplication unit 36 in FIG. 3) and the first frequency-corrected frequency by the correction means.
A carrier recovery unit (for example, the carrier recovery unit 47 in FIG. 3) that recovers the carrier using the received signal of the second carrier, and a second carrier whose frequency has been corrected using the carrier recovered by the second carrier recovery unit. A second correction unit (for example, the multiplication unit 49 in FIG. 3) for correcting the phase of one received signal is provided.

FIG. 1 is a block diagram showing an example of the configuration of a transmission device 1 constituting a transmission / reception system to which the present invention is applied. In this example, the signal to be transmitted (input data)
Are supplied to the switch 10. The unique word generation unit 11 generates a unique word W1 to be arranged in the synchronization burst signal and supplies the unique word W1 to the switch 10. After the switch 10, the switch 12
The switch 12 is supplied with the unique word W2 generated by the unique word generator 13.

The convolutional code unit 14 applies a convolutional code with a code rate of に 対 し て to the data supplied from the switch 12, and outputs a QASK (Quadrature Amplitude Shift Keyin).
g) Output to the mapping unit 15. Q
The ASK mapping unit 15 performs mapping on a predetermined signal point according to the data supplied from the convolutional coding unit 14, and converts the in-phase component (I) and the quadrature component (Q) into QAM (Q
uadrature Amplitude Modulation). The in-phase component and the quadrature component of the transmission signal are further QAM-modulated by the QAM modulator 16 so that BPSK (Binary Phase Shift Keying) modulation is consequently performed. Thereafter, the BPSK-modulated transmission signal is supplied to a Nyquist filter (raised cosine roll-off filter) 17, where the waveform is shaped, and then output to the transmission path 2.

Here, assuming that the signal to be transmitted (input data) is, for example, TMCC in the transmitting apparatus 1, the switch 10
, And at the same time, the switch 12 switches to select the data from the switch 10. That is, first, the unique word W generated by the unique word generator 11
1 will be supplied to the convolutional encoder 14. Next, the switch 10 switches so that TMCC as input data continues after the unique word W1. Then, after that, the switch 12 is switched so that the unique word w2 from the unique word generation unit 13 continues after TMCC. Then, from the convolutional code unit 14, FIG.
The synchronous burst signal shown in (C) is output. Thereafter, the signal is subjected to BPSK modulation and the waveform is shaped, and then output to the transmission path 2.

Although the above description has been made on the assumption that the synchronization burst signal is a transmission signal, if the transmission signal is a data burst, the transmission signal is transmitted to the QASK mapping section 15 and the QAM modulation section 16 by, for example, 8PSK.
The data is modulated and transmitted.

FIG. 2 schematically shows a transmission line such as a satellite line. In this transmission line 2,
The signal transmitted from the transmitting device 1 (in this case, a synchronous burst signal) is supplied to the receiving device 3 after being multiplied by noise or added with a frequency offset.

FIG. 3 is a block diagram showing a configuration example of the transmission device 3 constituting the transmission / reception system to which the present invention is applied. In this example, a signal transmitted from the receiving device 1 via the transmission path 2 is supplied to the delay unit 31, the separation unit 32, and the delay unit 42. The delay unit 31 delays the supplied received signal and supplies the received signal to the multiplier 36. The separating unit 32 separates the supplied received signal into an in-phase component and a quadrature component. The in-phase component and the quadrature component output from the separation unit 32 are subjected to waveform shaping by a Nyquist filter 33 and a Nyquist filter 34, respectively.
Supplied to The carrier reproducing unit 35 reproduces a carrier in response to the supplied received signal (details will be described later with reference to FIG. 4).
3 is output. The delay unit 42 delays the supplied received signal by a predetermined delay amount, and outputs the received signal to the multiplication unit 43.

The multiplication unit 36 multiplies the reception signal supplied from the delay unit 31 by the carrier reproduced by the carrier reproduction unit 35, and outputs the result to the separation unit 37. Separating section 37 separates the received signal supplied from multiplying section 36 into an in-phase component and a quadrature component, and outputs the signals to Nyquist filter 38 and Nyquist filter 39, respectively. The in-phase component and the quadrature component output from the separation unit 37 are
After the waveform is shaped by the Nyquist filter 38 and the Nyquist filter 39, respectively, the QASK demapping unit 40
Is demapped by The demapped reception signal is supplied to the unique word detection unit 41.

The multiplication section 43 multiplies the reception signal output from the delay section 42 by the carrier signal reproduced by the carrier reproduction section 35 and outputs the result to the separation section 44 and the delay section 48.
The separating unit 44 separates the received signal supplied from the multiplying unit 43 into an in-phase component and a quadrature component, and outputs the signals to the Nyquist filter 45 and the Nyquist filter 46, respectively. The in-phase component and the quadrature component filtered by the Nyquist filter 45 and the Nyquist filter 46 are supplied to a carrier reproducing unit 47. The carrier regenerating section 47 regenerates the carrier in accordance with the outputs of the Nyquist filter 45 and the Nyquist filter 46 (this point will be described later with reference to FIG. 5).

The received signal delayed by the delay unit 48 is
The output is output to the multiplier 49. The multiplication unit 49 multiplies the reception signal supplied from the delay unit 48 by the carrier reproduced by the carrier reproduction unit 47, and outputs the result to the separation unit 50.
The separation unit 50 separates the received signal supplied from the multiplication unit 50 into an in-phase component and a quadrature component. The in-phase component and the quadrature component output from the separating unit 50 are supplied to a QASK demapping unit 53 after their waveforms are shaped by a Nyquist filter 51 and a Nyquist filter 52, respectively, and are demapped. The output of the QASK demapping unit 53 is supplied to a unique word detection unit 54.

The unique word detecting section 41 has a value of the unique word w2 set in advance.
The correlation with the received signal output from the demapping unit 40 is obtained every 20 bits, and the correlation value is output to the correlation value synthesizing unit 55. Similarly, the unique word detection unit 54 sets the value of the unique word w1 and outputs a correlation value between the value and the received signal supplied from the QASK demapping unit 53 to the correlation value synthesis unit 55.
The correlation value synthesizing unit 55 synthesizes (adds) the correlation values from the unique word detecting unit 41 and the unique word detecting unit 54,
When the value exceeds a predetermined threshold, a detection signal is output. That is, when the unique word detection unit 41 and the unique word detection unit 54 detect the unique word w2 and the unique word w1, respectively, a detection signal is output. Note that the correlation value synthesizing unit 55 is reset when the detection signal is output.

FIG. 4 is a block diagram showing a detailed configuration example of the carrier reproducing unit 35. The in-phase component (I) and the quadrature component (Q) from the Nyquist filter 33 and the Nyquist filter 34 in FIG. 3 are supplied to a synthesizing unit 81, synthesized as a complex signal, and then squared by a multiplying unit 82. This means that the modulation component has been removed. Multiplication unit 83
Compares the phase of the output of the multiplication unit 82 with the phase of the output of the phase inversion unit 99, and outputs the complex signal corresponding to the error to the phase
4 is output. The phase extraction unit 84 extracts a phase signal from the complex signal supplied from the multiplication unit 83, and
To the amplifier 87.

The amplifying section 86 and the amplifying section 87 amplify the supplied phase signal and output the amplified signals to the adding section 90 and the adding section 88, respectively. The addition unit 88 adds the phase signal supplied from the amplification unit 87 and the phase signal delayed by the delay unit 89, and outputs the result to the delay unit 89 and the addition unit 90. The delay unit 89 outputs the phase signal supplied from the adder 88 to the adder 88 after delaying the phase signal. Adder 90
Is the phase signal supplied from the amplification unit 86 and the addition unit 88
The supplied phase signals are added and output to the adding unit 92. A lag-lead type loop filter 85 is constituted by the amplification unit 86 to the addition unit 90.

The adder 92 adds the output of the loop filter 85 (the output of the adder 90) and the output of the delay unit 94, and outputs the result to the modulo [mod] [0, 2π] unit 93. The modulo [0, 2π] unit 93 converts the output of the addition unit 92 into a value in the range of 0 to 2π, and outputs the values to the delay unit 94 and the delay unit 9.
5 is output. The delay unit 94 and the delay unit 95 delay the phase signal output from the modulo [0, 2π] unit 93, and then output the delayed signal to the addition unit 92 and the conversion unit 96, respectively. The conversion unit 96 converts the phase signal supplied from the delay unit 95 into a complex signal, and then converts the phase inversion unit 97 and the multiplication unit 98
Output.

The phase inverting section 97 includes a converting section 96 of the VCO 91.
The output phase signal is inverted and output to the multipliers 36 and 43 in FIG. Multiplication unit 98
Squares the output of the conversion unit 96 of the VCO 91 and outputs it to the phase inversion unit 99. The phase inverter 99 inverts the phase signal supplied from the multiplier 98 and outputs the inverted signal to the multiplier 83. As a result, the PLL of the reception signal (reception carrier) is configured.

FIG. 5 is a block diagram showing a detailed configuration example of the carrier reproducing section 47. This carrier reproducing unit 47
Form a primary loop. The in-phase component (I) and the quadrature component (Q) from the Nyquist filter 45 and the Nyquist filter 46 in FIG.
After being synthesized as a complex signal, the signal is squared by the multiplication unit 102 to remove a modulation component. The multiplication unit 103 compares the phase of the output of the multiplication unit 102 with the phase of the output of the phase inversion unit 113, and outputs a complex signal corresponding to the error to the phase extraction unit 104. The phase extraction unit 104 extracts a phase signal from the complex signal supplied from the multiplication unit 103, and
5 is output.

The amplifying section 105 amplifies the supplied phase signal and outputs the amplified signal to the adding section 106. The adding unit 106
A phase signal supplied from the amplification unit 105 and a delay unit 108
And add the modulo [0,2]
π] unit 107. Modulo [0, 2π] section 107 converts the output of adder section 106 to a value in the range of 0 to 2π and outputs the result to delay section 108 and delay section 109. The delay unit 108 is a modulo [0, 2π] unit 107
Is output to the adding unit 106 after the delay of the output.

The delay unit 109 delays the phase signal output from the modulo [0, 2π] unit 107,
10 is output. The conversion unit 110 converts the phase signal supplied from the delay unit 109 into a complex signal, and then outputs the complex signal to the phase inversion unit 111 and the multiplication unit 112. The phase inverting unit 111 inverts the phase signal output from the converting unit 110 and outputs the inverted signal to the multiplying unit 49 in FIG. The multiplier 112 squares the output of the converter 110 and outputs the result to the phase inverter 113. The phase inverter 113 inverts the phase signal supplied from the multiplier 112 and outputs the inverted signal to the multiplier 103.

Next, the operation of the receiver 3 will be described assuming that the synchronous burst signal shown in FIG. 6C is received. First, the received signal of the unique word w1 is
, The unique word w
2 is received and supplied to the delay unit 31 and the separation unit 32. Then, the received signal of the unique word W2 is supplied to the carrier reproducing unit 35 via the separating unit 32 and the Nyquist filters 33 and 34, and the received carrier is reproduced. Next, the unique word w delayed by the delay unit 31
The received signal of the unique word w1 delayed by the delay unit 42 is received by the multiplication unit 43.
In addition, the carrier reproduced by the carrier reproducing unit 35 (the carrier reproduced using the received signal of the unique word w2) is supplied to the multiplying unit 36 and the multiplying unit 45 at the same timing. Thereby, the unique word w2 output from the delay unit 31 at the same timing
And the received signal of the unique word w1 output from the delay unit 42 are synchronized with the carrier reproduced by the carrier reproducing unit 35. As a result, the frequency of the received signal of the unique word w1 and the frequency of the received signal of the unique word w2 are matched (corrected).

The received signal of the unique word w1 whose frequency has been corrected is then applied to the carrier (unique word w1) reproduced by the carrier reproducing unit 47 by the multiplier 49.
Is multiplied by the carrier corresponding to the received signal of (i), and the phase is corrected.

As described above, in the receiving device 3, at the timing when the unique word w1 and the unique word w2 are received (accurately, when the unique word w2 is received), the synchronization of the frequency and the phase is established. can do.

After the received signal of the unique word w1 and the received signal of the unique word w2 are subjected to waveform shaping and demodulation processing, the unique word detection unit 41 and the unique word detection unit 54 use the unique word w1 and the unique word detection unit 54, respectively.
The correlation value is detected as a unique word w2 (correlation value is obtained), and each correlation value is output to the correlation value synthesizing unit 55. Then, the correlation value synthesizing section 55 outputs a detection signal indicating that the unique word has been detected. As a result, a time reference for reception synchronization is obtained.

In the above description, the unique word w
Although the case of 1 and the unique word w2 has been described, the same operation is performed in the case of the unique word w1 and the unique word w3.

As a providing medium for providing a user with a computer program for performing the above-described various processes, a recording medium such as a magnetic disk, a CD-ROM, a solid-state memory, and a communication medium such as a network and a satellite may be used. Can be.

[0039]

As described above, in the information processing apparatus according to claim 1, the information processing method according to claim 3, and the providing medium according to claim 4, the first information corresponding to the second unique word is provided. Regenerate the carrier using the frequency of the received signal of
Using the carrier, the frequency of the first received signal and the frequency of the second received signal corresponding to the second unique word are corrected, and the carrier is changed using the frequency-corrected first received signal. The carrier is reproduced, and the carrier is used to correct the phase of the first received signal whose frequency has been corrected. Therefore, the carrier can be reproduced with less phase jitter, so that the reception synchronization is more reliably established. It becomes possible.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration example of a transmission device configuring a transmission / reception system to which the present invention has been applied.

FIG. 2 is a diagram schematically showing a transmission path.

FIG. 3 is a block diagram illustrating a configuration example of a reception device configuring a transmission / reception system to which the present invention has been applied.

FIG. 4 is a block diagram illustrating a configuration example of a carrier reproducing unit 35 of FIG. 3;

FIG. 5 is a block diagram illustrating a configuration example of a carrier reproducing unit 47 of FIG. 3;

FIG. 6 is a diagram illustrating a configuration example of a synchronization burst signal.

[Explanation of symbols]

31, 42, 48 delay unit, 32, 37, 44, 50
Separation part, 33, 34, 38, 39, 45, 46, 5
1,52 Nyquist filter, 35,47 carrier regenerating unit, 36,43,49 multiplying unit, 40,53
QASK demapping unit, 41, 54 unique word detection unit, 55 correlation value synthesis unit 55

Claims (4)

[Claims] A first unique word, predetermined data,
And an information processing apparatus for establishing reception synchronization using a signal composed of a second unique word, wherein a first carrier for reproducing a carrier using a frequency of a first reception signal corresponding to the second unique word is provided. Using the carrier reproduced by the carrier reproducing unit, correcting the frequency of the first received signal and the frequency of the second received signal corresponding to the second unique word using the carrier reproduced by the first reproducing unit. A first correction unit that performs frequency correction by the first correction unit.
Second carrier regenerating means for regenerating a carrier using the received signal of the above, and correcting the phase of the frequency-corrected first received signal using the carrier reproduced by the second carrier regenerating means. An information processing apparatus comprising: a second correction unit. 2. The information processing apparatus according to claim 1, wherein the predetermined data is TMCC. 3. A first unique word, predetermined data,
And an information processing method for establishing reception synchronization using a signal constituted by a second unique word, comprising: a first step of reproducing a carrier using a frequency of a first reception signal corresponding to the second unique word; Correcting the frequency of the first received signal and the frequency of the second received signal corresponding to the second unique word by using the carrier reproduced in the carrier reproducing step and the first reproducing step A first correction step of performing the frequency correction in the first correction step.
A second carrier reproducing step of reproducing a carrier by using the received signal of step (c), and correcting the phase of the frequency-corrected first received signal by using the carrier reproduced in the second carrier reproducing step. A second correction step. 4. The first unique word, predetermined data,
And an information processing apparatus that establishes reception synchronization using a signal composed of a second unique word, and a first carrier that reproduces a carrier using a frequency of a first reception signal corresponding to the second unique word. Correcting the frequency of the first received signal and the frequency of the second received signal corresponding to the second unique word by using the carrier reproduced in the carrier reproducing step and the first reproducing step A first correction step of performing the frequency correction in the first correction step.
A second carrier reproducing step of reproducing a carrier by using the received signal of step (c), and correcting the phase of the frequency-corrected first received signal by using the carrier reproduced in the second carrier reproducing step. Providing a computer-readable program including a second correction step.