JP2007159040A - Received frame synchronization method and receiving apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve a frequency pull-in characteristic and simultaneously to increase a detection speed of a frame timing without degradation of information transmission efficiency in a received frame synchronization method in a wireless communication system such as a spread spectrum communication system. <P>SOLUTION: On a transmitting side, a data frame 100 including a pilot symbol is constructed by using a code sequence, for example a comma-free code sequence or a prefix comma-free code sequence, which is repeated for each symbol group (slot) composed of M (M>1) number of symbols as a pilot symbol pattern and of which a timing of a separator between symbol groups can be recognized. In a receiving side, timing synchronization information which is the separator between symbol groups is recognized by the pilot symbol pattern. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a received frame synchronization method, and more particularly to a method and a receiving apparatus for establishing frame synchronization of a received signal in a wireless communication system such as a spread spectrum communication method that requires channel estimation in a transmission path.

  Conventionally, as a method of establishing frame synchronization of a received signal, a method of establishing frame synchronization by inserting a synchronization word composed of a known bit string into a transmission signal on the transmission side and detecting the synchronization word on the reception side is generally used. Is. As a method for improving the characteristics for establishing and maintaining the synchronization, there are a method for increasing the number of bits of the synchronization word, a method for using protection by continuously detecting a plurality of synchronization words, and the like.

  FIG. 6 shows a configuration of a general communication apparatus. In the communication apparatus 600 shown in FIG. 6, the received signal passes through the demodulating circuit 11, analog / digital converters (A / D) 12 and 13, and the signal reproducing circuit 14 of the receiving unit 1, and then to the synchronizing circuit 15 and the signal extracting circuit 16. Sent. The synchronization circuit 15 synchronizes slots and frames, and the decoder 2 decodes the signal extracted by the signal extraction circuit 16 to obtain received data. On the other hand, the transmission data is output as a transmission signal through the encoder 3, the frame mapping circuit 41 of the transmission unit 4, the waveform shaping filters 42 and 43, the digital / analog converters (D / A) 44 and 45, and the modulation circuit 46.

  In a cellular mobile CDMA radio system such as W / CDMA (Wideband Code Division Multiple Access) proposed as one of radio communication specifications in a third generation mobile communication system, a pilot channel is transmitted from a base station. The period of the spreading code of this channel matches the frame period. Therefore, the terminal (mobile station) on the receiving side can establish frame synchronization in a short time by synchronizing the spreading code of this pilot channel. The pilot channel symbol data is known, but the pilot channel symbol pattern is fixed at 0 or 1.

  In W / CDMA, a primary synchronization channel (PSCH: Primary Synchronization Channel) and a secondary synchronization channel (SSCH: Secondary Synchronization Channel) are multiplexed on the downlink as dedicated synchronization channels. The slot period is detected by, and the frame period is detected by SSCH. FIG. 7 shows a concept of a data frame configuration up to PSCH. As shown in FIG. 7, in a W / CDMA downlink data frame 700, a synchronization channel (synchronization word) for cell search is inserted in a part of broadcast information. The terminal on the receiving side detects the timing of each cellular using this synchronization channel.

  By the way, as a typical automatic frequency control (AFC) method used in the spread spectrum of the direct spread (DS) method used in CDMA or the like, the received spread spectrum signal is despread. There is a method using the relationship between the magnitude of the correlation value obtained in this way and the frequency deviation. The method of using the relationship between the magnitude of the correlation value and the frequency deviation is used for a receiver of a global positioning system (GPS), and the initial frequency deviation with respect to the transmission symbol rate and the carrier frequency. Effective when the fluctuation is large due to the Doppler shift.

  As another AFC method, there is a method of discriminating a phase variation of a reproduction symbol obtained by despreading a received spectrum spread signal. This method is used for W / CDMA terminals and the like, and the initial frequency deviation is small relative to the transmission symbol rate and the carrier frequency, but the residual after initial pull-in is required to be small. It is effective in the case.

  The following techniques are known for communication using the CDMA system using spread spectrum as described above. For example, after inserting pilot symbols in the transmission signal and detecting the correlation between the spreading code received on the receiving side and the replica of the spreading code prepared on the receiving side, the spreading codes are synchronized with each other An initial synchronization method for confirming whether or not synchronization between spreading codes is truly established depending on whether or not frame synchronization can be detected using pilot symbols is known (see, for example, Patent Document 1). In addition, the synchronization code is transmitted periodically, the synchronization code transmission period is made equal to the long code period of the downlink, and the synchronization code transmission position is made to coincide with the head of the long code, and the mobile station detects the correlation with the synchronization code. A spread-spectrum communication apparatus that performs the above-mentioned is known (for example, see Patent Document 2).

  Further, by inserting pilot symbols at regular intervals between information symbols, and by making a spreading code for spreading the pilot symbols in a plurality of code channels common among the code channels, mutual communication between the pilot symbols of each code channel is achieved. A direct spread CDMA transmission method in which the correlation is removed is known (for example, see Patent Document 3). Also, a direct spread CDMA transmission method is known in which a plurality of code channels are divided into several blocks, and frames with different pilot symbol insertion positions are used for each block to improve fading follow-up performance of channel estimation. (For example, refer to Patent Document 4).

Japanese Patent No. 2905907 Japanese Patent Laid-Open No. 9-307951 JP 2003-163650 A Japanese Patent No. 3623787

  However, in the conventional frame synchronization method described above, when the number of bits of the synchronization word is increased, redundant bits other than the information to be transmitted are increased, so that the actual information transmission efficiency is lowered. is there. In addition, when protection using continuous detection of a plurality of synchronization words is used, there is a problem that the time required for establishing synchronization increases. Further, in a system with a long frame period or a system with a small capacity of line capacity, there are problems that synchronization maintenance performance is deteriorated and synchronization acquisition time becomes long.

  Further, when it is necessary to achieve both frame synchronization and carrier frequency synchronization in the initial pull-in after power-on, if the pilot period is long, it is difficult to synchronize the carrier frequency first. In such a case, frame synchronization is established before synchronization of the carrier frequency, but there is a problem that sufficient frame synchronization performance cannot be obtained because the carrier frequency is not synchronized. Further, in the case of W / CDMA, there is a problem in that the presence of PSCH and SSCH synchronization channels disturbs orthogonality between channels in downlink code multiplexing, leading to performance degradation.

  The present invention provides a reception frame synchronization method and a reception apparatus that can improve both the frequency pull-in characteristics and the speed of frame timing detection without causing a decrease in information transmission efficiency in order to eliminate the above-described problems caused by the prior art. The purpose is to do.

  In order to solve the above-described problems and achieve the object, in the reception frame synchronization method according to the present invention, the transmission side repeats each symbol group consisting of M (M> 1) symbols as a pilot symbol pattern. A data frame including a pilot symbol is configured using a code sequence that can recognize the timing of separation between symbol groups. On the receiving side, timing synchronization information that is a delimiter of symbol groups is recognized by a pilot symbol pattern. Here, a data frame configuration in which a symbol group including M symbols is repeated in a slot period may be employed.

  In the reception frame synchronization method according to the present invention, on the transmission side, the data frame is composed of a small symbol group consisting of M symbols and a large symbol group consisting of N (N> 1) small symbol groups. . The pilot symbol pattern is repeated for each of the N small symbol groups so that the timing of separation between the large symbol groups can be recognized, and the pattern is different for each small symbol group belonging to the same large symbol group. A data frame including pilot symbols is configured using a code sequence that can recognize the timing of the break between each other. On the receiving side, the timing synchronization information that is a delimiter between the large symbol group and the small symbol group is recognized based on the pilot symbol pattern.

  In the reception frame synchronization method according to the present invention, when a data frame composed of the small symbol group and the large symbol group is configured on the transmission side, a small symbol is repeated as a pilot symbol pattern for each small symbol group. A first code sequence capable of recognizing the timing of separation between groups is used. Then, the code of the symbol obtained using the first code sequence is repeated for each large symbol group in units of small symbol groups to be a second code sequence that can recognize the timing of the separation between the large symbol groups. The data frame including the pilot symbols is constructed by changing based on it. On the receiving side, the timing synchronization information that is a delimiter between the large symbol group and the small symbol group is recognized based on the pilot symbol pattern. Here, a data frame configuration may be adopted in which a small symbol group composed of M symbols is repeated in a slot period, and a large symbol group composed of N small symbol groups is repeated in a frame period.

  In the received frame synchronization method according to the present invention, when a data frame is constructed on the transmission side, a synchronization word may be provided for a part or all of the multiplexed channels other than the pilot channel. In this case, on the receiving side, a synchronization word is detected after detecting a pilot symbol pattern, thereby obtaining timing synchronization as a symbol group delimiter. In the present invention, a plurality of synchronization words may be provided on the transmission side, and at least one synchronization word may be detected on the reception side to obtain timing synchronization as a symbol group delimiter.

  In the receiving apparatus according to the present invention, the pilot symbol pattern is repeated for each symbol group composed of M (M> 1) symbols as a data frame including pilot symbols, and the timing of the separation between the symbol groups is recognized. A signal using a possible code sequence may be configured to have synchronization means for recognizing timing synchronization information that becomes a delimiter of the symbol group by the pilot symbol pattern.

  In the above invention, a code sequence having a high autocorrelation, a comma-free code sequence, or a prefix comma-free code sequence that is repeated in a certain transmission time unit can be used as the code sequence. In addition, a PN sequence code including an M sequence or a Gold sequence code that is generally used as a synchronization word can be used. Further, if the code sequence is repetitive in a certain transmission time unit and can recognize the timing of the separation of a plurality of symbols, a part of the code of any of the comma-free code sequence, the prefix comma-free code sequence, the M sequence and the Gold sequence You can also use only.

  According to the present invention, the symbol period can be detected by the spreading code period by making the spreading code period equal to the pilot symbol length. Further, the slot period and frame period can be detected by the pilot symbol pattern. Here, although the spreading code length does not necessarily match the symbol period, the symbol timing can always be captured and the slot can be increased by setting the spreading code length to a few symbols that are sufficiently shorter than the slot or frame period. Timing and frame timing can be detected. Therefore, the time required for pulling in timing synchronization can be shortened.

  In W / CDMA, which is a cellular system, it is necessary to use a different spreading code in each base station in order to separate and combine a plurality of base stations when receiving at a terminal (mobile station). However, in applications such as so-called Hotspot (registered trademark) intended for communication within a single cell, it is not necessary to increase the number of types of spreading codes as in a cellular system. Therefore, no problem occurs even if the spreading code length is about several symbols.

  In addition, according to the present invention, the correlation value due to symbol despreading decreases when the frequency deviation is large and becomes maximum when there is no frequency deviation. A frequency search by comparing the magnitudes of correlations can be performed on all symbols. Therefore, automatic frequency control (AFC) before frame synchronization is possible, and frequency pull-in characteristics can be improved.

  Furthermore, according to the present invention, since PSCH and SSCH are unnecessary, orthogonality between channels can be maintained. Therefore, it is possible to avoid performance degradation due to disorder of orthogonality. Further, since a synchronization word as in the prior art is unnecessary or even when a synchronization word is provided, synchronization maintenance performance can be improved without increasing redundant bits, so that information transmission efficiency is improved. With the above operation or effect, the configuration of the synchronization circuit provided in the receiving unit of the communication device can be simplified.

  According to the present invention, there is an effect that it is possible to improve both the frequency pull-in characteristic and the speed of frame timing detection without causing a decrease in information transmission efficiency.

  Exemplary embodiments of a reception frame synchronization method and a reception apparatus according to the present invention will be explained below in detail with reference to the accompanying drawings.

(Embodiment 1)
FIG. 1 is a diagram for explaining a data frame configuration according to the first embodiment of the present invention. As shown in FIG. 1, in the data frame 100 of the first embodiment, as an example, a symbol group consisting of five symbols of symbol patterns 1 to 5 has a one-slot period. This is because, in order to simplify the explanation here, a binary comma-free code with a code length of 5 is used as a code sequence that can be repeated for each symbol group to recognize the timing of the separation between the symbol groups. is there. That is, the symbol patterns 1 to 5 correspond in order to any one symbol of “00001”, “10001”, “11001”, “00101”, or “10101”.

  For example, when “00001” is used, symbol pattern 1, symbol pattern 2, symbol pattern 3, symbol pattern 4 and symbol pattern 5 are “0”, “0”, “0”, “0” and “1”, respectively. " The spreading code length is about several symbols, and here is the same as the pilot symbol period. The spreading code is multiplied by each symbol pattern 1-5. In this case, for example, “0” and “1” of the code sequence are multiplied as “+1” and “−1”, respectively. Therefore, if the symbol pattern is “0”, the code of the spreading code remains as it is, and the symbol pattern remains unchanged. If “1” is “1”, the sign of the spreading code is inverted.

  By adopting such a data frame configuration, a delimiter between consecutive code sequences is uniquely determined, so that the position of each symbol in the slot period can be maintained even if the spreading code length is the pilot symbol period. As a result, since the autocorrelation peak for each symbol of the spread code is obtained for the replica of the same code on the receiving side, symbol timing can be extracted and frequency synchronization can be obtained in the synchronizing circuit on the receiving side. it can. Further, since it is possible to notify the slot period of other channels without using a synchronization word, slot timing can be extracted. Further, for example, the configuration of the synchronization circuit 15 provided in the receiving unit of the communication apparatus as shown in FIG. 6 can be simplified.

  Note that the same effect can be obtained by using a code other than a comma-free code having a code length of 5 as a code sequence that can be repeated for each symbol group to recognize the timing at which the symbol groups are separated. If the code length is an odd number, a comma-free code can be created. Also, a prefix comma-free code may be used instead of the comma-free code, and in that case, a code having an even code length can be created.

  Furthermore, as a code having an odd code length and suitable as a synchronization word, there is a PN sequence code including an M sequence. Even if this code is used, the same effect can be obtained. For example, when the slot period is composed of 7 symbols, a binary M-sequence code having a code length of 7 (for example, “1110100”) may be used. The same effect can be obtained by using a Gold code having a sharp peak in autocorrelation. The same effect can be obtained by cutting out a part of various codes to create a sequence having sufficiently high autocorrelation. In this case, a code with an even code length can be created. In addition to the above-described codes, the same effect can be obtained if the code sequence has a high autocorrelation that is repeated in a certain transmission time unit.

(Embodiment 2)
FIG. 2 is a diagram for explaining a data frame configuration according to the second embodiment of the present invention. As shown in FIG. 2, in the data frame 200 of the second embodiment, as an example, a small symbol group consisting of five symbols of symbol patterns 1 to 5 has a one-slot period. This is because a binary comma-free code having a code length of 5 is used as in the first embodiment. In addition, a large symbol group is formed by five small symbol groups, so that one frame period is formed by a 5-slot period. This is because there are five types of binary comma-free codes having a code length of “00001”, “10001”, “11001”, “00101”, and “10101”.

  The relationship between the symbol patterns 1 to 5 and the spreading code in one slot period is as described in the first embodiment. However, different codes are used among the five types of binary comma-free codes in the five slot periods constituting one frame period. For example, in one frame, “00001” is used as the symbol pattern group 1 including the symbol patterns 1 to 5 in the first slot. In each of the second, third, fourth, and fifth slots, “10001”, “11001” are represented as symbol pattern group 2, symbol pattern group 3, symbol pattern group 4, and symbol pattern group 5 each including symbol patterns 1 to 5, respectively. "," 00101 "and" 10101 "are used.

  By adopting such a data frame configuration, it is possible to notify the receiving side of a period of a plurality of symbol breaks longer than in the first embodiment. Therefore, the timing synchronization information that becomes a delimiter of a plurality of symbols longer than that in the first embodiment can be recognized on the receiving side. Further, the frame timing can be detected by detecting at least one slot symbol pattern on the receiving side. As in the first embodiment, a code other than a comma-free code having a code length of 5 may be used as the code sequence.

(Embodiment 3)
FIG. 3 is a diagram for explaining a data frame configuration according to the third embodiment of the present invention. As shown in FIG. 3, in the data frame 300 according to the third embodiment, as an example, a small symbol group consisting of 7 symbols of symbol patterns 1 to 7 has a one-slot period. This is because a binary M-sequence code having a code length of 7 (for example, “1110100”) is used as the first code sequence that can be repeated for each small symbol group to recognize the timing of separation between the small symbol groups. It is. In addition, a large symbol group is formed by five small symbol groups, so that one frame period is formed by a 5-slot period. This is because a binary comma-free code having a code length of 5 is used as the second code sequence that can be repeated for each large symbol group to recognize the timing of the separation between the large symbol groups.

  The relationship between the symbol patterns 1 to 7 and the spreading code in one slot is the same as the relationship between the symbol patterns 1 to 5 and the spreading code in one slot described in the first embodiment. That is, when “1110100” is used as a binary M-sequence code having a code length of 7, symbol pattern 1, symbol pattern 2, symbol pattern 3, symbol pattern 4, symbol pattern 5, symbol pattern 6 and symbol pattern 7 are: “1”, “1”, “1”, “0”, “1”, “0”, and “0”, respectively. Then, by multiplying each symbol pattern 1 to 7 by the spreading code, a symbol group of each slot is obtained.

  When “00001” is used as a binary comma-free code of code length 5, slot pattern 1 and slot pattern 2 corresponding to the first, second, third, fourth, and fifth slots in one frame. The slot pattern 3, the slot pattern 4, and the slot pattern 5 are “0”, “0”, “0”, “0”, and “1”, respectively. The sign of the symbol group of each slot is changed by multiplication with the corresponding slot patterns 1-5. If the slot pattern is “0”, the sign of the symbol group of the slot corresponding thereto is unchanged, and if the slot pattern is “1”, the sign of the symbol group of the slot corresponding thereto is inverted.

  By adopting such a data frame configuration, it is possible to notify the receiving side of a period of a plurality of symbol breaks longer than in the first embodiment. Therefore, the timing synchronization information that becomes a delimiter of a plurality of symbols longer than that in the first embodiment can be recognized on the receiving side. Further, the pattern of the second code sequence may be changed for each frame. For example, for the first frame period, “00001” is used as a binary comma-free code with a code length of 5, and for each of the second, third, fourth, and fifth frame periods, “10001”, “11001”, “00101”, and “10101” may be used. By doing so, the receiving side can be further notified of the period of the delimitation of a plurality of long symbols, and the receiving side can recognize the timing synchronization information that becomes the delimitation of a plurality of longer symbols. Note that, as each code sequence, a code other than a binary M-sequence code with a code length of 7 or a code other than a comma-free code with a code length of 5 may be used as in the first embodiment.

(Embodiment 4)
FIG. 4 is a diagram for explaining a data frame configuration according to the fourth embodiment of the present invention. As shown in FIG. 4, in addition to the configuration of the first embodiment, the data frame 400 of the fourth embodiment is obtained by assigning a synchronization word to one symbol of broadcast information. Here, a synchronization word is assigned to the head of the broadcast information slot. On the receiving side, as in the first embodiment, the symbol period is detected by the spreading code period, and the slot period is detected by the pilot symbol patterns 1 to 5, whereby the synchronization word insertion timing can be recognized. By adopting such a data frame configuration and using the same timing detection as in the first embodiment and synchronization confirmation by symbols assigned as synchronization words, the synchronization word allocation is increased even in a longer slot period. Without this, it is possible to improve the reliability of the establishment of timing synchronization and the synchronization maintenance performance. A synchronization word may be assigned to two or more symbols in one slot.

(Embodiment 5)
FIG. 5 is a diagram for explaining a data frame configuration according to the fifth embodiment of the present invention. As shown in FIG. 5, the data frame 500 of the fifth embodiment is obtained by assigning synchronization words to two or more slots of broadcast information in the fourth embodiment. That is, a synchronization word is provided in each of the plurality of slots. Here, synchronization word 1 is assigned to the first symbol of one slot of the broadcast information, and synchronization word 2 is assigned to the first symbol of the next slot. By adopting such a data frame configuration, the same effect as in the fourth embodiment can be obtained. Further, as in the second embodiment, it is possible to establish frame synchronization by detecting at least one synchronization word without receiving all symbols of the frame.

(Supplementary note 1) When a data frame including pilot symbols is constructed on the transmission side, the pilot symbol pattern is repeated for each symbol group consisting of M (M> 1) symbols, and the timing of the separation between the symbol groups is set. Using a recognizable code sequence,
A receiving frame synchronization method comprising: recognizing timing synchronization information as a delimiter of the symbol group by the pilot symbol pattern on a receiving side.

(Supplementary note 2) The received frame synchronization method according to supplementary note 1, wherein the symbol group is repeated at a slot period.

(Supplementary Note 3) When a data frame including pilot symbols is constructed on the transmission side, the data frame is divided into a small symbol group consisting of M (M> 1) symbols and N (N> 1) small symbols. A small symbol group composed of a large symbol group consisting of symbol groups, which is repeated for each of the N small symbol groups as a pilot symbol pattern, and the timing of delimitation between the large symbol groups can be recognized, and belongs to the same large symbol group Each pattern has a different pattern and uses a code sequence that can recognize the timing of the break between small symbol groups,
A reception frame synchronization method characterized in that, on the receiving side, timing synchronization information that is a delimiter for each of the large symbol group and the small symbol group is recognized by the pilot symbol pattern.

(Supplementary Note 4) When a data frame including pilot symbols is configured on the transmission side, the data frame is divided into a small symbol group consisting of M (M> 1) symbols and N (N> 1) small symbols. The first code sequence is composed of a large symbol group consisting of symbol groups, and is used as a pilot symbol pattern, which is repeated for each small symbol group and can recognize the timing of separation between the small symbol groups. Changing the sign of the symbol obtained by using the second code sequence that is repeated for each large symbol group in units of the small symbol group and can recognize the timing of the separation between the large symbol groups,
A receiving frame synchronization method, wherein timing synchronization information for separating each of the large symbol group and the small symbol group is recognized by the pilot symbol pattern on the receiving side.

(Supplementary note 5) The received frame synchronization method according to supplementary note 3 or 4, wherein the small symbol group is repeated at a slot period, and the large symbol group is repeated at a frame period.

(Supplementary note 6) A synchronization word is provided on a part or all of multiplexed channels other than the pilot channel on the transmission side,
The timing synchronization information serving as a delimiter of the symbol group is obtained by detecting the synchronization word after detecting the pilot symbol pattern on the receiving side. Receive frame synchronization method.

(Appendix 7) A plurality of the synchronization words are provided on the transmission side,
7. The reception frame synchronization method according to appendix 6, wherein timing synchronization information for delimiting the symbol group is obtained by detecting at least one synchronization word on the reception side.

(Supplementary note 8) The received frame synchronization method according to any one of supplementary notes 1 to 7, wherein the code sequence is a code sequence having high autocorrelation repeated in a certain transmission time unit.

(Supplementary note 9) The received frame synchronization method according to any one of supplementary notes 1 to 7, wherein the code sequence is a comma-free code sequence.

(Supplementary note 10) The received frame synchronization method according to any one of supplementary notes 1 to 7, wherein the code sequence is a prefix comma-free code sequence.

(Supplementary note 11) A communication apparatus comprising a synchronization circuit that synchronizes with the reception frame synchronization method according to any one of Supplementary notes 1 to 10.

(Supplementary note 12) A receiving device,
As a data frame including a pilot symbol, a signal using a code sequence in which a pilot symbol pattern is repeated for each symbol group composed of M (M> 1) symbols and the timing of the separation between the symbol groups can be recognized, A receiving apparatus, comprising: synchronization means for recognizing timing synchronization information that is a delimiter of the symbol group based on the pilot symbol pattern.

  As described above, the present invention is useful for a wireless communication system such as a spread spectrum communication system that requires channel estimation in a transmission path, and is particularly suitable for a direct spread system spread spectrum communication system such as CDMA. .

It is a figure for demonstrating the data frame structure concerning Embodiment 1 of this invention. It is a figure for demonstrating the data frame structure concerning Embodiment 2 of this invention. It is a figure for demonstrating the data frame structure concerning Embodiment 3 of this invention. It is a figure for demonstrating the data frame structure concerning Embodiment 4 of this invention. It is a figure for demonstrating the data frame structure concerning Embodiment 5 of this invention. It is a figure which shows the structure of a general communication apparatus. It is a figure for demonstrating the data frame structure of the downlink of W / CDMA.

Explanation of symbols

  100, 200, 300, 400, 500 data frames

Claims (5)

When a data frame including pilot symbols is constructed on the transmission side, a code sequence that can be repeated for each symbol group consisting of M (M> 1) symbols as a pilot symbol pattern to recognize the timing of the separation between the symbol groups Use
A receiving frame synchronization method comprising: recognizing timing synchronization information as a delimiter of the symbol group by the pilot symbol pattern on a receiving side. When constructing a data frame including pilot symbols on the transmitting side, the data frame is composed of a small symbol group consisting of M (M> 1) symbols and N (N> 1) small symbol groups. It is composed of large symbol groups, and is repeated for every N small symbol groups as pilot symbol patterns so that the timing of separation between large symbol groups can be recognized, and a pattern is provided for each small symbol group belonging to the same large symbol group. Unlike, using a code sequence that can recognize the timing of the break between small symbol groups,
A receiving frame synchronization method, wherein timing synchronization information for separating each of the large symbol group and the small symbol group is recognized by the pilot symbol pattern on the receiving side. When constructing a data frame including pilot symbols on the transmitting side, the data frame is composed of a small symbol group consisting of M (M> 1) symbols and N (N> 1) small symbol groups. A first symbol sequence which is composed of a large symbol group and is repeated for each small symbol group as a pilot symbol pattern and can recognize the timing of the separation between the small symbol groups is obtained using the first code sequence. Changing the sign of each symbol based on a second code sequence that can be repeated for each large symbol group in units of the small symbol group to recognize the timing of the separation between the large symbol groups,
A receiving frame synchronization method, wherein timing synchronization information for separating each of the large symbol group and the small symbol group is recognized by the pilot symbol pattern on the receiving side. A synchronization word is provided for some or all of the multiplexed channels other than the pilot channel on the transmission side,
The timing synchronization information serving as a delimiter of the symbol group is obtained by detecting the synchronization word after detecting the pilot symbol pattern on the receiving side. Received frame synchronization method. A receiving device,
As a data frame including a pilot symbol, a signal using a code sequence in which a pilot symbol pattern is repeated for each symbol group composed of M (M> 1) symbols and the timing of the separation between the symbol groups can be recognized, A receiving apparatus, comprising: synchronization means for recognizing timing synchronization information that is a delimiter of the symbol group based on the pilot symbol pattern.

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