JP4693866B2 - Terminal apparatus, base station, and communication method - Google Patents

Description

  The present invention relates to a terminal device, a base station, and a communication method that perform single carrier communication, for example.

Conventionally, a method in which a base station receives a single carrier signal with a cyclic prefix (Cyclic prefix: CP) transmitted from multiple terminal devices in a batch using Fast Fourier Transform (FFT) is known. . For collective reception, the transmission timing from each terminal device needs to be controlled to the FFT timing of the base station. However, in Patent Document 1, for example, timing is detected from the delay profile of each terminal device, On the other hand, timing control is realized by feeding back timing information.
JP 2007-96468

  However, when the signal bandwidth of a single carrier from a certain terminal device increases or decreases, for example, when the symbol rate changes, the optimal FFT timing (reception timing) at the base station will be different. In the method, there is a problem that it takes time to perform optimum timing control when the signal bandwidth of a single carrier from a certain terminal device increases or decreases.

  That is, when the signal bandwidth of the single carrier transmitted by the terminal device is changed in the method of Patent Document 1, the base station first receives the transmission signal of the terminal device, detects the timing error, and based on the result. Optimal timing control is possible only when timing information is generated and fed back to the terminal device. For this reason, it takes time until optimal timing control is performed, and the timing of the transmission signal from the terminal device during that time is not optimal, so that the reception characteristics at the base station deteriorate, and the adjacent channel is adversely affected. There was a problem.

  The present invention provides a terminal device, a base station, and a communication method capable of optimizing the FFT timing in a base station in a short time when the symbol rate is changed.

The terminal device as one aspect of the present invention is:
Block generating means for generating a block of a predetermined time length by adding a repetition symbol having the same waveform as a partial waveform including the other end of the plurality of symbols to one end of a plurality of temporally continuous symbols;
The higher timing earlier than the symbol rate symbol rate as a reference for the block and the lower the timing later than the symbol rate symbol rate is the reference of the blocks, by modifying the specified transmission timing of the block, Transmission timing determining means for determining a transmission timing for transmitting the block generated by the block generating means;
Transmission means for transmitting the block generated by the block generation means at the transmission timing determined by the transmission timing determination means,
Regardless of the symbol rate of each block generated by the block generation means, the time length of each block is the same, and the time length of the repetitive symbol included in each block is the same.

The base station as one aspect of the present invention is:
Receiving means for receiving, from a terminal device, a block of a predetermined time length in which a repetition symbol having the same waveform as a partial waveform including the other waveform of the plurality of symbols is added to one end of a plurality of temporally continuous symbols;
Fourier transform means for Fourier transforming the signal of the block received by the receiving means in a section corresponding to the length of the plurality of symbols;
Timing error detection means for detecting an error with respect to a desired timing of the Fourier transform of the signal of the block by the Fourier transform means;
Transmission timing calculation means for calculating a transmission timing for transmitting the block by the terminal device based on an error detected by the timing error detection means;
Symbol rate notification means for notifying the terminal device of a change in symbol rate;
When the symbol rate after the change is higher than the symbol rate of the block when the transmission timing is calculated by the transmission timing calculation means, the absolute value of the difference between the symbol rate after the change and the symbol rate of the block is large The transmission timing calculated by the transmission timing calculation means is corrected to an earlier timing,
When the symbol rate after the change is lower than the symbol rate of the block when the transmission timing is calculated by the transmission timing calculation means, the absolute value of the difference between the symbol rate after the change and the symbol rate of the block is large The transmission timing correction means for correcting the transmission timing calculated by the transmission timing calculation means to a later timing,
Timing information notifying means for notifying the terminal device of timing information representing the transmission timing corrected by the transmission timing correcting means;
With
Regardless of the change of the symbol rate of the terminal device, the time length of each block received from the terminal device by the receiving means is the same, and the time length of the repetitive symbol included in each block is respectively Are the same .

A communication method as one aspect of the present invention includes:
A block generation step of generating a block of a predetermined time length by adding a repetition symbol having the same waveform as a partial waveform including the other end of the plurality of symbols to one end of a plurality of symbols that are temporally continuous;
The higher timing earlier than the symbol rate symbol rate as a reference for the block and the lower the timing later than the symbol rate symbol rate is the reference of the blocks, by modifying the specified transmission timing of the block, A transmission timing determination step for determining a transmission timing for transmitting the block generated by the block generation step;
A transmission step of transmitting the block generated by the block generation step at the transmission timing determined by the transmission timing determination step;
With
Regardless of the symbol rate of each block generated in the block generation step, the time length of each block is the same, and the time length of the repeated symbols included in each block is the same.

  According to the present invention, it is possible to optimize the FFT timing in the base station in a short time when the symbol rate is changed.

  Hereinafter, the present embodiment will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a diagram showing a configuration example of a mobile communication system according to the first embodiment.

  In the mobile communication system according to the present embodiment, a base station CS1 and a plurality of terminal devices PS1, PS2,... That communicate with the base station CS1 belong. A plurality of terminal apparatuses PS1, PS2,... Transmit signals simultaneously at different frequencies f1, f2,..., And the base station CS1 receives these transmission signals all at once.

  Each terminal device encodes information bits, modulates the encoded bits, adds a CP (Cyclic Prefix) to generate a block, and transmits the generated block. The terminal device transmits a data block, a pilot block, a synchronization block, and the like as a block. Examples of data blocks are shown in FIGS. 2 (a) to 2 (c).

  The data block in FIG. 2 (a) includes eight data symbols (data portion) and a cyclic prefix (repeated symbol) that is copied from the rear end 1 symbol of the data portion and added to the front end. The data block shown in FIG. 2B includes 16 data symbols (data portion) and a cyclic prefix (repeated symbol) that is added to the front end by copying two rear end symbols of the data portion. The data block in FIG. 2 (c) includes 32 data symbols (data portion) and a cyclic prefix (repeated symbol) that is added to the front end by copying the rear end 4 symbols of the data portion. The time lengths of the data blocks in FIGS. 2A to 2C are the same. By adding a cyclic prefix as shown in Fig. 2 (a) to Fig. 2 (c), the received signal can be equalized in the frequency domain on the receiving side, and even in a multipath environment with relatively simple calculations. High reception quality can be maintained. In the example of FIG. 2, a part from the rear end of the data part is copied to the front end, but a part from the front end of the data part may be copied to the rear end. In this case, the symbol added to the rear end corresponds to a repeated symbol. In this way, the terminal device generates and transmits a block having a predetermined time length in which the same waveform as the partial waveform including the other end of the plurality of symbols is added to one end of the plurality of temporally continuous symbols.

  Each terminal apparatus in FIG. 1 can transmit a block by switching two or more different symbol rates. For example, the terminal device can transmit blocks by switching three different symbol rates shown in FIGS. 2 (a), 2 (b), and 2 (c). Of course, the terminal device can also transmit at a symbol rate other than the symbol rate shown in FIG.

  Each terminal apparatus in FIG. 1 communicates with a base station in units of slots composed of a plurality of blocks. An example of the slot format that defines the format of the slot transmitted by each terminal device is shown in FIG. In the example of FIG. 3, one synchronization block, two pilot blocks, and 16 data blocks constitute one slot. In addition, a guard time is provided between the temporally continuous slots.

  FIG. 4 is a block diagram illustrating a configuration of the terminal device.

  The upper layer unit 11 performs processing of layers higher than the MAC (Media Access Control) layer. The upper layer unit 11 outputs information obtained in the upper layer to the MAC unit 12 during transmission, and receives information from the MAC unit 12 to the upper layer during reception.

The MAC unit 12 performs MAC layer processing. The MAC unit 12 performs MAC layer processing on the information to be transmitted received from the upper layer unit 11 and outputs the processed information to the modulation unit 13. Further, the MAC unit 12 transmits symbol rate information indicating the current symbol rate, timing information (described later) notified from the base station indicating transmission timing designated by the base station, and transmitted to the base station during initial timing synchronization. Initial symbol rate information (described later) representing the symbol rate (initial symbol rate) of the block is received from the upper layer unit 11 and output to the timing calculation unit 14.
The current symbol rate corresponds to, for example, an example of a second symbol rate, and the initial symbol rate corresponds to, for example, an example of an Xth symbol rate, which is a symbol rate serving as a predetermined reference. Further, the MAC unit 12 receives demodulated data from a demodulating unit 28 described later, extracts data for the upper layer from the received demodulated data, and passes it to the upper layer unit 11.

  The modulation unit 13 generates a digital baseband modulation signal based on the information input from the MAC unit 12, and outputs the generated digital baseband modulation signal to the CP adding unit 15.

  The CP adding unit 15 generates a block by adding a cyclic prefix (CP) in block units to the digital baseband modulated signal input from the modulating unit 13, and sends the generated block signal to the FIR unit 16. Output. The MAC unit 12, the modulation unit 13, and the CP addition unit 15 form, for example, a block generation unit.

  The FIR unit 16 performs a filtering process on the block signal input from the CP adding unit 15 with a Root Raised Cosine Filter configured with a finite filter length to limit the signal band, and timing the filtered block signal Output to the adjustment unit 17.

  Based on the symbol rate information, timing information, and initial symbol rate information input from the MAC unit 12, the timing calculation unit 14 calculates transmission timing information that determines the transmission timing at which the block should be transmitted, and calculates the calculated transmission timing. Information is output to the timing adjustment unit 17. The timing calculation unit 14 corresponds to, for example, transmission timing determination means.

  The timing adjustment unit 17 sends the filtered block signal input from the FIR unit 16 to the DA (Digital-to-Analog) conversion unit 18 in accordance with the transmission timing indicated by the transmission timing information input from the timing calculation unit 14. Output. For example, the timing adjustment unit 17 may measure the output timing based on the timing at which the power of the symbol at the head of the block becomes maximum, or may measure the output timing based on other timings. The timing adjustment unit 17 corresponds to a transmission unit, for example.

  The DA conversion unit 18 converts the digital block signal input from the timing adjustment unit 17 into an analog block signal, and outputs the analog signal to an LPF (Low Pass Filter) unit 19.

  The LPF unit 19 performs a filtering process using an LPF (Low Pass Filter) to remove harmonic components from the analog signal input from the DA conversion unit 18, and converts the filtered baseband analog signal into a UC (Up- Converter) section 20 outputs.

  The UC unit 20 up-converts the analog baseband signal input from the LPF unit 19 to a desired RF (Radio Frequency) to generate an RF signal, and outputs the generated RF signal to a PA (Power Amplifier) unit 21. .

  The PA unit 21 power-amplifies the RF signal input from the UC unit 20 and outputs the power-amplified RF signal to the switch unit 22.

  The switch unit 22 switches the switch so that the power amplified RF signal input from the PA unit 21 is output to the antenna unit 23 during transmission, and the signal received by the antenna unit 23 is output to the LNA unit 24 during reception. .

  The antenna unit 23 radiates the RF signal input from the switch unit 22 to the space as a radio wave during transmission, and receives a signal transmitted from the base station during reception.

  The LNA (Low Noise Amplifier) unit performs low noise amplification processing on the RF signal from the base station input from the switch unit 23, and the low noise amplification processed RF signal is supplied to the DC (Down-Converter) unit 25. Output.

  The DC unit 25 down-converts the RF signal input from the LNA unit 24 into an analog baseband signal and outputs the analog baseband signal to an LPF (Low Pass Filter) unit 26.

  The LPF unit 26 performs a filtering process using an LPF (Low Pass Filter) in order to remove the harmonic component from the analog baseband signal input from the DC unit 25, and the analog signal from which the harmonic component is removed is converted to AD ( (Analog-to-Digital) output to the converter 27.

  The AD conversion unit 27 converts the analog signal input from the LPF unit 26 into a digital signal and outputs the digital signal to the demodulation unit 28.

  The demodulator 28 demodulates the digital signal input from the AD converter 27 and outputs demodulated data to the MAC unit 12.

  Hereinafter, a method of calculating transmission timing information in the timing calculation unit 14 will be described with reference to FIG. However, the following description is merely an example, and the present invention is not limited to the following method.

  FIG. 5 is a block diagram illustrating a configuration of the timing calculation unit 14.

  The base station notification timing information storage unit 31 receives from the MAC unit 12 timing information notified from the base station at the time of initial timing synchronization (initial connection), every fixed time period, or when it is determined that the base station is necessary. . The timing information is acquired as follows, for example. At the time of timing synchronization, a first signal for performing timing synchronization is transmitted from the terminal device to the base station. Here, it is assumed that the initial timing synchronization is assumed, and the first signal for performing the initial timing synchronization is notified by the block of the initial symbol rate. Based on the first signal included in the block signal, the base station that has received the first signal reports an error (eg, notifies the first signal) of the transmission timing of the block that has notified the first signal. Error for the desired timing of the FFT timing performed on the signal of the block), the transmission timing to be applied by the terminal device is determined based on the detected error, and the timing information indicating the determined transmission timing is determined by the terminal Notify the device.

となる。基地局通知タイミング情報記憶部３１は、この累積和Δt_CSをタイミング加減算部３４に出力する。 More specifically, this timing information represents a relative time difference with respect to the current transmission timing, and the base station notifies the timing information that the transmission timing is shifted by the relative time difference with respect to the current transmission timing. ing. The base station notification timing information storage unit 31 calculates and stores a cumulative sum of timing information notified from the base station and received from the MAC unit 12 after starting communication. That is, assuming that the relative time difference notified at the nth time after starting communication is Δt _n , the cumulative sum Δt _CS stored in the base station notification timing information storage unit 31 is:

It becomes. The base station notification timing information storage unit 31 outputs the accumulated sum Δt _CS to the timing addition / subtraction unit 34.

  The initial symbol rate storage unit 32 stores the initial symbol rate information input from the MAC unit 12. The initial symbol rate information defines the symbol rate used at the time of initial timing synchronization.

The symbol rate comparison unit 33 receives current symbol rate information from the MAC unit 12 and receives initial symbol rate information from the initial symbol rate storage unit 32, and compares these pieces of information. As a result of comparison, if the current symbol rate and the initial symbol rate are the same, 0 (zero) is output to the timing adder / subtractor 34, and if the current symbol rate is higher,
Δt _compO = _{−Δt compH} (Δt _compH > 0)
Is output to the timing addition / subtraction unit 34, and if the initial symbol rate is higher,
Δt _compO = Δt _compL (Δt _compL > 0)
Is output to the timing addition / subtraction unit 34. Δt _compO corresponds to a transmission timing time to be delayed. If Δt _compO <0, the absolute value of Δt _compO corresponds to the transmission timing time to be advanced.

Here, when the current symbol rate is higher than the initial symbol rate, the larger the absolute value of these differences, the larger the value of Δt _compH , and conversely, the initial symbol rate is higher than the current symbol rate. When the rate is higher than the rate, the larger the absolute value of these differences, the larger the value of Δt _compL . The values of Δt _{compH and} Δt _compL may be determined in advance according to, for example, each set of the initial symbol rate and the current symbol rate, or the initial symbol rate value and the current symbol rate value are used. You may calculate by calculation.

The timing addition / subtraction unit 34 adds the cumulative sum Δt _CS input from the base station notification timing information storage unit 31 and Δt _compO input from the symbol rate comparison unit 33, and the result Δt _out = Δt _CS + Δt _CompO is output to the timing adjustment unit 17 as transmission timing information.

Thus, when transmitting at a symbol rate higher than the initial symbol rate, the timing calculation unit 14 transmits at a timing that is relatively earlier by Δt _compH than the transmission timing specified by the base station, and at a symbol rate lower than the initial symbol rate. When transmitting, the transmission timing information is calculated so that transmission is performed at a timing relatively delayed by Δt _compL from the transmission timing designated by the base station. Hereinafter, this reason will be described with reference to FIG.

  FIG. 6A is a diagram for explaining optimum FFT timing of a block (see FIG. 2A) transmitted by the terminal device at the symbol rate r. The transmission waveform of the CP symbol and each of the first to eighth symbols is filtered in time by the FIR unit 16 of FIG. 4 and spreads in time. In this example, each symbol spreads to 6 symbols. When the base station receives the transmission waveform of this block as it is, the optimum FFT timing (reception timing) is the timing surrounded by a dotted line. Optimum in this case means that the desired signal energy contained in the block after CP removal on the receiving side is maximum. Originally, if the spread of the transmission waveform of each symbol is within the CP length, it is possible to perform FFT at the timing of picking up all of the spread of each transmission waveform. In this case, this timing is the optimum FFT timing. However, in FIG. 6A, since the spread of the transmission waveform by the filtering process exceeds the CP length, the desired signal energy included in the block after CP removal on the reception side is always smaller than the energy on the transmission side. . Therefore, in practice, the timing at which the energy loss is minimized is the optimum FFT timing.

  The optimum FFT timing will be described in more detail with reference to FIG.

  When the FFT timing shown in FIG. 6 (a) is made earlier by 2 symbols (the FFT timing is shifted by 2 symbols to the left side of FIG. 6 (a)), the CP symbol and the first one as shown in FIG. 7 (a). The energy of all the symbols can be received, but the sixth and seventh symbols cannot receive even their main lobes.

  As shown in Fig. 7 (b), when receiving at a timing one symbol later than Fig. 7 (a), all the energy of the 8th symbol corresponding to the CP symbol and the energy of the 1st symbol can be received. The received energy of the symbols in the latter half of the block, such as the 7th symbol and the 7th symbol, also increases compared to FIG. However, if reception is performed at a later FFT timing than in FIG. 7B, the reception energy of the first symbol starts to be lost. Since the eighth symbol is repeated for the first CP symbol and the rearmost symbol, there is no energy loss of the eighth symbol.

  On the other hand, as shown in FIG. 7 (c), if the FFT timing is delayed by 2 symbols from FIG. 6 (a), the energy of the 7th and 8th symbols in the latter half of the block can all be received, but the 1st symbol And the second symbol cannot receive even those main lobes.

  As shown in FIG. 7 (d), when receiving at a timing earlier by one symbol than in FIG. 7 (c), the energy of the eighth symbol and the seventh symbol corresponding to the CP symbol can all be received, and the first The received energy of the symbols in the first half of the block, such as the second symbol and the second symbol, also increases compared to FIG. However, when receiving at an FFT timing earlier than FIG. 7 (d), the reception energy of the seventh symbol starts to be lost.

Due to the symmetry, the timing that is intermediate between the FFT timing in FIG. 7B and the FFT timing in FIG. 7D is the optimum FFT timing that most suppresses energy loss. More generally, the leading timing t _first (see FIG. 7A) of the waveform spread of the leading symbol (first symbol) in the block excluding the CP symbol and the symbol in the block excluding the symbol repeated as the CP symbol. The timing of the center of the rear end symbol (for example, the seventh symbol) with respect to the rear end timing t _last (see FIG. 7A) of the waveform spread is the timing t _mid (see FIG. 7A), and the center of the FFT section the timing and t _rx (see FIG. 7 (a)), the timing of t _rx matches the t _mid is the optimal FFT timing. That is, the timing surrounded by the dotted line in FIG. 6 (a) is the optimum FFT timing.

  In the above, the optimum FFT timing has been shown by taking the symbol rate r in FIG. 6A as an example. However, the optimum FFT timing for other symbol rates is as follows.

FIG. 6B is a diagram for explaining optimum FFT timing of a block (see FIG. 2B) transmitted by the terminal device at the symbol rate 2r. When considered in the same manner as in FIG. _6A , it can be understood that the timing surrounded by the dotted line in FIG. 6B, that is, the timing later by Δt _compL than FIG. _6A is the optimum FFT timing.

FIG. 6C is a diagram for explaining optimum FFT timing of a block (see FIG. 2C) transmitted by the terminal device at the symbol rate 4r. Considering the same as in the case of FIG. _6A , the timing surrounded by the dotted line in FIG. 6C, that is, the timing later by Δt _compL + Δt _compH than FIG. _6A is the optimum FFT timing. Recognize.

  Here, the blocks of FIGS. 6 (a), 6 (b), and 6 (c) have the same CP length, the same block length, and only the symbol rate. When blocks with different symbol rates are transmitted at the same transmission timing, and the signals of each block are FFTed at the same timing via the same transmission path, even if the FFT is performed at the optimal timing for a block with a certain symbol rate, This is not the optimal FFT timing for a symbol rate block. Therefore, if the terminal device makes the transmission timing earlier or later according to the symbol rate, and the base station receives at the same timing regardless of the symbol rate, the base station It is possible to perform FFT at the optimal timing.

For example, it is assumed that the terminal device transmits a symbol rate 2r block to the base station at the first time, and the base station receives the block at the optimum FFT timing. Optimal FFT timing may be realized by notifying the terminal device of timing information (feedback information) related to timing in advance from the base station, and the terminal device adjusting the transmission timing based on this timing information. It may be realized by adjusting the FFT timing on the side. At the second time after the first time, when the terminal apparatus transmits the symbol rate r block to the base station, the terminal apparatus transmits it at a timing that is later by Δt _compL than the timing at which the symbol rate 2r block is transmitted. On the base station side, if the FFT is performed at the same timing as the symbol rate 2r block, the symbol rate r block can be FFTed at the optimum timing. Then, when the terminal device transmits the symbol rate 4r block to the base station at the third time after the second time, it is earlier by Δt _compL + Δt _compH than the timing of transmitting the symbol rate r block. If transmission is performed at the timing and FFT is performed at the same timing as the block of the symbol rate r on the base station side, the block of the symbol rate 4r can be FFTed at the optimal timing.

  FIG. 8 shows the optimal transmission timing when transmitting each block of symbol rate r, symbol rate 2r, and symbol rate 4r in the above example.

It is assumed that the terminal device transmits a symbol rate 2r block to the base station, and the base station performs FFT at the optimum timing. Block transmission period is assumed to be T _B. If the terminal continues to transmit remains symbol rate 2r, the base station can continue to receive a block of symbol rate 2r at the optimal FFT timing if continues to receive at block period T _B. On the other hand, if (at to r in this example) to which the terminal lower symbol rate, the terminal device to slow the transmission timing only Delta] t _COMPL, if the base station continues to receive at block period T _B, the optimal FFT timing Can continue to be received. Also, (to 4r in this example) to increase the symbol rate case, the transmission timing is earlier by Delta] t _COMPH, if the base station adopts continues received at block period T _B, it may continue to receive at an optimal FFT timing Is possible.

  The above description is based on the case where the transmission path is one wave, but the same can be said in a multipath environment. In the case of a multipath environment consisting of a plurality of n (n> 2) waves, when considering only the kth (1 = <k = <n) wave, the same thing can be said as when the transmission path is one wave, This is because the multipath environment can be expressed by linear addition from the first wave to the nth wave. Therefore, the above description holds in common for a general propagation environment.

  As described above, according to this embodiment, the higher the symbol rate of the block to be transmitted, the faster the transmission timing, and the lower the symbol rate, the slower the transmission timing, thereby changing the symbol rate. In this case, it is possible to shorten the time until the optimum FFT timing is realized in the base station.

(Second embodiment)
FIG. 9 is a block diagram illustrating a configuration of a terminal device according to the second embodiment. The difference from FIG. 4 is the operation of the MAC unit and the timing calculation unit, and the other blocks are the same as those in FIG.

  The MAC unit 41 performs processing of the MAC layer, outputs information to be transmitted to the modulation unit 13, symbol rate information indicating the current symbol rate, timing information notified from the base station, the current number of CP symbols, Initial symbol rate information indicating the symbol rate (initial symbol rate) of the block transmitted to the base station for initial timing synchronization, and the number of CP symbols in the block transmitted by the terminal device for initial timing synchronization (number of initial CP symbols) ) Is output to the timing calculation unit 42.

  The timing calculation unit 42 calculates transmission timing information based on these pieces of information input from the MAC unit 41 and outputs the calculated timing information to the timing adjustment unit 17.

  FIG. 10 is a block diagram illustrating a configuration of the timing calculation unit 42.

  Since the base station notification timing information storage unit 31, the initial symbol rate storage unit 32, and the timing addition / subtraction unit 34 are the same as those in FIG. 5, description thereof is omitted here.

  The initial CP symbol number storage unit 51 stores the initial CP symbol number input from the MAC unit 41.

The difference calculation unit 52 receives the initial CP symbol number from the initial CP symbol number storage unit 51 and receives initial symbol rate information from the initial symbol rate storage unit 32. The difference calculation unit 52 receives the current symbol rate information and the current number of CP symbols from the MAC unit 41. The initial CP symbol number is S _ini , the initial symbol rate is r _ini , the current symbol rate is r _now , and the current CP symbol number is S _now , and the difference calculation unit 52 calculates Δt _compO from these values according to the following formula _: And the calculated Δt _compO is output to the timing addition / subtraction unit 34.

となる。ただし、rはシンボルレート、S(r)はシンボルレートrのときのCPシンボル数、Fは帯域制限用フィルタ(図９のFIR部に相当する)による送信波形広がりの幅をシンボル数で表したものである。CPシンボルに繰り返されるシンボルを除くブロック内の後端シンボルの波形広がりの後端タイミングt_lastは、

となる。ただし、T_BdataはCP長を除くブロック長（すなわちFFT区間長）である。よってt_midは、

となる。FFTの開始タイミングt_sとt_rxの関係は、

である。t_rx=t_midとなるタイミングが最適なFFTタイミングであるから、

となる。シンボルレートr₁とシンボルレートr₂のそれぞれの場合における最適なFFTタイミングの差分Δt_sは以下のように算出できる。

The derivation of the above equation will be described. As described in the first embodiment, the optimum FFT timing is determined by the leading edge timing t _first of the waveform spread of the leading symbol in the block excluding the CP symbol and the trailing symbol in the block excluding the symbol repeated in the CP symbol. the timing of the center of the rear end timing t _last waveform spread the timing t _mid, when the center timing of the FFT interval was t _rx, timing t _rx matches the t _mid is the optimal FFT timing. The tip timing t _first of the waveform spread of the tip symbol in the block excluding the CP symbol is

It becomes. Where r is the symbol rate, S (r) is the number of CP symbols at the symbol rate r, and F is the width of the transmission waveform spread by the band limiting filter (corresponding to the FIR part in FIG. 9) in number of symbols. Is. The rear end timing t _last of the waveform spread of the rear end symbol in the block excluding the symbols repeated in the CP symbol is

It becomes. However, _TBdata is the block length excluding the CP length (that is, the FFT interval length). So t _mid is

It becomes. Relationship between the start timing t _s and t _rx of the FFT,

It is. The timing at which t _rx = t _mid is the optimal FFT timing.

It becomes. Difference Delta] t _s optimal FFT timing in each case the symbol rate r ₁ and the symbol rate r ₂ can be calculated as follows.

  The above derivation is a derivation in the case where the number of CP symbols is uniquely determined by the symbol rate, but can be similarly derived even when the number of CP symbols does not depend on the symbol rate.

In the above, the initial symbol rate r _ini corresponds to, for example, the X-th symbol rate value r _x which is a predetermined symbol rate, and the initial CP symbol number S _ini is, for example, the X-th symbol rate. This corresponds to the number of repetitive symbols S _x included in the block. The current symbol rate r _now corresponds to, for example, the second symbol rate value r ₂ that is the symbol rate after the change, and the current number of CP symbols S _now is, for example, a repeated symbol included in the block of the second symbol rate It corresponds to the number of S _2.

As is understood from the calculation formula of Δt _compO , the timing calculation unit 42 calculates the difference between these when (S _now −1) / r _now is larger than (S _ini −1) / r _ini . The transmission timing at the current (for example, changed) symbol rate is determined so that the larger the absolute value is, the earlier the transmission timing at the initial symbol rate, and (S _ini -1) / r _ini is (S _now -1) When larger than / r _now, the transmission timing at the current (for example, changed) symbol rate is determined so that the larger the absolute value of these differences is, the later the transmission timing at the initial symbol rate. When (S _now -1) / r _now and (S _ini -1) / r _ini are the same, the transmission timing is not changed.

(Third embodiment)
FIG. 11: has shown the block diagram which shows the structure of the terminal device concerning a 3rd Example. The difference from FIG. 9 is the operation of the MAC unit and the timing calculation unit, and the other blocks are the same as in FIG.

  The MAC unit 43 performs processing of the MAC layer, outputs information to be transmitted to the modulation unit 13, and calculates the current symbol rate information, timing information notified from the base station, and the current number of CP symbols. To the unit 44.

  The timing calculation unit 44 calculates transmission timing information based on the symbol rate information, timing information, and the number of CP symbols input from the MAC unit 43, and outputs the calculated transmission timing information to the timing adjustment unit 17.

  FIG. 12 is a block diagram illustrating a configuration of the timing calculation unit 44.

  The previous information storage unit 45 stores the symbol rate information and the number of CP symbols of the previous block (or the previous transmission slot). When the symbol rate information and the number of CP symbols are input from the MAC unit 43, the previous information storage unit 45 stores the previous block (or the previous transmission slot) stored in the memory in the previous information storage unit 45. ) Is output to the difference calculation unit 46, and the symbol rate information and the CP symbol number input from the MAC unit 43 are stored in the memory in the previous information storage unit 45.

The difference calculation unit 46 receives the symbol rate information and the CP symbol number S _now from the MAC unit 43, and receives the symbol rate information and CP of the previous block (or the previous transmission slot) from the previous information storage unit 45. The number of symbols S _pre is input. The difference calculating unit 46 calculates the current symbol rate r _now , the symbol rate r _pre of the previous block (or the previous transmission slot), the current CP symbol number S _now, and the previous block ( or from a CP symbol number S _pre of the preceding transmission slot), and calculates a Delta] t _COMPO by the following equation.

The difference calculation unit 46 outputs this Δt _compO to the timing addition / subtraction unit 47.

The timing addition / subtraction unit 47 adds the timing information Δt _CS input from the MAC unit 43 and Δt _compO input from the difference calculation unit 46, and _uses the result Δt _out1 = Δt _CS + Δt _compO as transmission timing information. The information is output to the base station notification timing information storage unit 48. Timing information Δt _CS is notified from the base station when initial timing is synchronized, every fixed period of time, or when the base station determines that it is necessary. When nothing is input, it is determined that Δt _CS = 0 is input. To do.

となる。基地局通知タイミング情報記憶部４８は、この記憶値Δt_out2を送信タイミング情報としてタイミング調整部１７に出力する。 The base station notification timing information storage unit 48 receives timing information Δt _out1 from the timing addition / subtraction unit 47 for each transmission slot, for example. The base station notification timing information storage unit 48 stores a cumulative sum of timing information Δt _out1 input after communication is started. That is, if the transmission timing input at the nth time after starting communication is Δt _out1 (n), the stored value Δt _out2 stored in the base station notification timing information storage unit 48 is

It becomes. The base station notification timing information storage unit 48 outputs the stored value Δt _out2 to the timing adjustment unit 17 as transmission timing information.

In the above, the symbol rate r _pre is, for example, the symbol rate immediately before being changed to the second symbol rate corresponds to a symbol rate r _x of the X, CP symbol number S _pre, for example symbol rate of the X This corresponds to the number of repetitive symbols S _x included in the block.
The current symbol rate r _now corresponds to, for example, the second symbol rate value r ₂ that is the symbol rate after the change, and the current number of CP symbols S _now is the repetition included in the second symbol rate block, for example. It corresponds to the number S ₂ symbols.

As can be understood from the calculation formula of Δt _compO , the timing calculation unit 44 calculates these differences when (S _now −1) / r _now is larger than (S _pre −1) / r _pre . The transmission timing at the changed symbol rate is determined so that the larger the absolute value is, the earlier the transmission timing of the previous symbol rate, and (S _pre -1) / r _pre is (S _now -1) / r _now Is larger, the transmission timing at the changed symbol rate is determined so that the larger the absolute value of these differences is, the slower the transmission timing at the immediately preceding symbol rate is. When (S _now -1) / r _now and (S _pre -1) / r _pre are the same, the transmission timing is not changed.

(Fourth embodiment)
FIG. 13 is a block diagram illustrating the configuration of the timing calculation unit of the terminal device according to the fourth embodiment.

  Since the base station notification timing information storage unit 31 and the timing addition / subtraction unit 34 are the same as those in FIG. 5, the description thereof is omitted here.

に相当する値を記憶する。ただし、初期タイミング同期に用いられる送信ブロックのCPシンボル数をS_ini、初期シンボルレートをr_iniとし、これらCPシンボル数S_iniと初期シンボルレートr_iniは予め決められた固定値であるとする。 The initial timing storage unit 61

The value corresponding to is stored. However, it is assumed that the number of CP symbols in the transmission block used for initial timing synchronization is S _ini , the initial symbol rate is r _ini, and these CP symbol numbers S _ini and initial symbol rate r _ini are predetermined fixed values.

The difference calculation unit 62 receives the current symbol rate information and the current CP symbol number S _now from the MAC unit, and the value t _pre from the initial timing storage unit 61. The difference calculation unit 62 calculates Δt _compO from the current symbol rate r _now , the current number of CP symbols S _now, and the value t _pre stored in the initial timing storage unit 61 by the following equation.

The difference calculation unit 62 outputs this Δt _compO to the timing addition / subtraction unit 34.

  Thus, when the number of CP symbols of the transmission block used for initial timing synchronization and the initial symbol rate are determined in advance, the calculation in the timing calculation unit can be simplified. The block diagram showing the configuration of the terminal device according to the present embodiment corresponds to the block diagram in FIG. 9 excluding the input of the initial symbol rate information and the initial CP symbol number from the MAC unit 41 to the timing calculation unit.

(Fifth embodiment)
FIG. 14 is a block diagram illustrating a configuration of the timing calculation unit of the terminal device according to the fifth embodiment.

  Since the base station notification timing information storage unit 31 and the timing addition / subtraction unit 34 are the same as those in FIG. 5, the description thereof is omitted here.

The timing table unit 71 has a table storing Δt _compO for all combinations of symbol rate and number of CP symbols. However, in this embodiment, it is assumed that the number of CP symbols S _ini and the initial symbol rate r _ini of the transmission block used for initial timing synchronization are fixed values predetermined by the system.

The timing table unit 71 reads Δt _compO by referring to the table using the symbol rate information input from the MAC unit and the number of CP symbols as parameters, and outputs the read Δt _compO to the timing addition / subtraction unit 34.

When the types of symbol rates employed in the transmission block and the number of CP symbols are finite, the combinations are also finite. Therefore, if Δt _compO is stored in _advance in the table for all combinations of each symbol rate and the number of each CP symbol, the calculation in the timing calculation unit can be simplified. As Δt _compO stored in the table, for example, a value obtained by the expression described in the second embodiment or the fourth embodiment may be used, but the value of the expression described in the second embodiment or the fourth embodiment is not necessarily used. However, in consideration of the reception timing margin and mounting error in the base station, a value in a range that does not greatly deviate from the value of the above equation may be applied.

In addition to the above, in the second embodiment, Δt _compO is calculated in advance according to each combination of the initial CP symbol number S _ini , the initial symbol rate r _ini , the current symbol rate r _now , and the current CP symbol number S _now. The calculated values are stored in the table in association with each combination, and the table is set with the initial CP symbol number S _ini , the initial symbol rate r _ini , the current symbol rate r _now , and the current CP symbol number S _now as parameters. Reference may be _made to read Δt _compO .

In the third embodiment, the current symbol rate r _now , the current number of CP symbols S _now , the symbol rate r _pre of the previous block (or the previous transmission slot), the previous block ( Alternatively, Δt _compO is calculated in advance in accordance with each combination of the number of CP symbols S _{pre in} the previous transmission slot), the calculated value is stored in a table in association with each combination, and the current symbol rate r _now The current CP symbol number S _now , the symbol rate r _{pre of} the previous block (or the previous transmission slot), and the CP symbol number S _pre of the previous block (or the previous transmission slot) Δt _compO may be read by referring to a table as a parameter.

(Sixth embodiment)
FIG. 15 is a diagram illustrating an example of transmission timing control when the terminal device transmits in slot units.

In the example of FIG. 15, one synchronization block (s), two pilot blocks (p), and 16 data blocks (d) constitute one slot. Each block is configured with a different number of symbols depending on the symbol rate, but the symbol rate of all the blocks included in one slot is the same. The terminal device transmits a _{slot at} every slot transmission cycle T _slot , and if the transmission symbol rate and CP length of each slot are the same, it transmits at the same slot timing, and either the transmission symbol rate or the CP length Alternatively, if both are changed, the transmission timing control described in the first to fifth embodiments is performed, and transmission is performed at the adjusted slot timing.

In addition, when the terminal apparatus is notified from the base station to change the transmission timing by Δt _Bs (not shown) between the transmission slots, for the slot timing after the transmission timing adjustment by the CP length or the symbol rate, Further, it is assumed that the transmission timing is changed by Δt _Bs .

(Seventh embodiment)
In this embodiment, transmission timing control when a so-called extended CP (extended repeated symbol) is included in a block will be described. In the following, the extended CP will be briefly described first, and then transmission timing control according to the present embodiment will be described in detail.

  FIG. 16 is a diagram for explaining the extended CP.

  The extended CP is a rear end symbol having the same waveform as the repetition symbol when a repetition symbol is added to the front end side in a block, or the rear end side when a repetition symbol is added to the rear end side. In the case where z symbols (z is an integer of 1 or more) preceding the repeated symbol are made the same as the symbols having the same waveform as the z symbols from the rear end symbol of the previous block. , These z symbols in the block.

  When the extended CP is adopted, the same effect as when the CP length is substantially extended can be expected. In this example, a case where two symbols are adopted as the extended CP is shown. For example, in data block 1 (data block 1), two symbols preceding the rear end side symbols 13 and 14 having the same waveform as the front end side repeated symbol (CP) are pilots immediately preceding data block 1. It is made the same as the two symbols c1 and c2 from the rear end of block 1 (pilot block 1), so these are extended CPs.

  If z extended CPs are used, for example, the z symbols immediately before the symbol repeated as the CP of each block depend on the previous block, so the extended CP is used for the known symbols like the pilot block. In the case of performing, the portion corresponding to the extended CP of the previous block (data block 2) (here, the last two blocks c15 and c16) as in pilot block 2 (pilot block 2) in FIG. It is necessary to adjust to 2.

  In addition, when a block composed of known symbols is transmitted continuously, such as when a synchronization block and a pilot block are transmitted continuously, the extended CP cannot normally be employed for the reasons described above. However, as shown in FIG. 16, a known symbol sequence consisting of symbols c1 to c16 is adopted as a synchronization symbol (sync block), and a sequence obtained by cyclically shifting the known symbol sequence is adopted as a pilot block (pilot block 1). This makes it possible to adopt an extended CP.

  Also, the synchronization block at the beginning of the slot may be transmitted without adopting the extended CP, or the CP length of the synchronization block may be simply extended. In the example of FIG. 16, transmission is performed without adopting the extended CP.

  FIG. 17 is a block diagram showing the configuration of the terminal device when the extended CP according to the seventh embodiment is used.

  The difference from FIG. 4 is the operation of the MAC unit 81, the timing calculation unit 82, and the modulation unit 83, and the other blocks are the same as those in FIG.

  The MAC unit 81 performs processing of the MAC layer, outputs information to be transmitted and information on the extended CP to the modulation unit 83, and calculates timing of symbol rate information, timing information notified from the base station, and the number of CP symbols To the unit 82.

  Modulation section 83 creates a digital baseband modulated signal including an extended CP based on the information input from MAC section 81 and outputs it to CP adding section 15 and outputs the number of extended CP symbols to timing calculation section 82. .

  The timing calculation unit 82 calculates and calculates transmission timing information based on the symbol rate information, timing information and the number of CP symbols input from the MAC unit 81 and the number of extended CP symbols input from the modulation unit 83. The transmission timing information is output to the timing adjustment unit 17.

  FIG. 18 is a block diagram illustrating a configuration of the timing calculation unit 82.

  Since the base station notification timing information storage unit 31 and the timing addition / subtraction unit 34 are the same as those in FIG. 5, description thereof is omitted here.

The timing table unit 91 has a table that stores Δt _compO for all combinations of the symbol rate, the number of CP symbols, and the number of extended CP symbols. The timing table unit 91 reads Δt _compO by referring to the table using the symbol rate information and the number of CP symbols input from the MAC unit 81 and the number of extended CP symbols input from the modulation unit 82 as parameters, and reads the read Δt _CompO is output to the timing addition / subtraction unit 34.

When the types of symbol rates employed in the transmission block, the number of CP symbols, and the number of extended CP symbols are finite, the combinations are also finite. Therefore, a value Δt _compO corresponding to all combinations of each symbol rate, each CP symbol number, and each extended CP symbol number is stored in the table in _advance . The value Δt _compO is obtained, for example, according to the following equation.

Here, S _ini is the number of CP symbols of the transmission block used for initial timing synchronization, S _Vini is the number of extended CP symbols of the transmission block used for initial timing synchronization, r _ini is the initial symbol rate of the transmission block used for initial timing synchronization, r Is the current symbol rate output from the MAC unit 81, S _now (r) is the current number of CP symbols output from the MAC unit 81, and S _Vnow (r) is the current extended CP symbol output from the MAC unit 81 Represents a number. However, the initial CP symbol number S _ini , the initial symbol rate r _ini , and the extended CP symbol number S _Vini are assumed to be fixed values predetermined by the system.

に置き換えることで求めることができる。 The derivation of this equation takes into account the extended CP for t _last described in the second embodiment,

Can be obtained by replacing

In this embodiment, Δt _compO is obtained by referring to the value of a table created in advance. However, the present invention is not limited to this method, and Δt _compO is calculated by directly calculating the above formula. May be. The value stored in the table does not necessarily match the value of the above formula, and a value within a range that does not greatly deviate from the value of the above formula is applied in consideration of the reception timing margin and mounting error in the base station. May be.

Here, in the above equation, r corresponds to the value r ₂ of the second symbol rate, S _now (r) corresponds to the number S _{2 of} repetitive symbols included in the block of the second symbol rate, and S _Vnow (r) corresponds to the number of extended repeated symbols S _v2 included in the block of the second symbol rate.
Also, r _ini corresponds to the value r _x of the Xth symbol rate, which is a predetermined reference symbol rate, and S _ini is the number of repetitive symbols S _x included in the block of the Xth symbol rate. S _Vini corresponds to the number of extended repeated symbols S _vx included in the block of the Xth symbol rate.

Then, as understood from the calculation formula of Δt _compO , the timing calculation unit 82 (S _now (r) -1- S _Vnow (r)) / r is (S _ini -1- S _Vini ) / r. When it is larger than _ini , the larger the absolute value of these differences is, the faster the transmission timing at the current (for example, the changed) symbol rate is earlier than the transmission timing at the initial symbol rate (for example, after the changing). Determine the transmission timing at the symbol rate,
When (S _ini -1- S _Vini ) / r _ini is greater than (S _now (r) -1- S _Vnow (r)) / r, the larger the absolute value of these differences, the more current (for example, after The transmission timing at the current (for example, changed) symbol rate is determined such that the transmission timing at the symbol rate is later than the transmission timing at the initial symbol rate.

In the calculation of Δt _compO , the CP symbol number S _{ini of} the transmission block used for initial timing synchronization, the extended CP symbol number S _{Vini of} the transmission block used for initial timing synchronization, and the initial symbol rate r _ini of the transmission block used for initial timing synchronization Instead, as in the third embodiment, the number of CP symbols, the number of extended CP symbols included in the block of the immediately preceding slot, and the symbol rate of the immediately preceding slot can be used.

Similarly to the fifth embodiment, the initial CP symbol number S _ini , the initial symbol rate r _ini , the extended CP symbol number S _Vini , the current symbol rate r, and the current CP symbol number S _now (r) Δt _compO is calculated in advance according to each combination of the extended CP symbol number Sv _now (r), and the calculated value is stored in a table in association with each combination, and the initial CP symbol number S _ini , the initial symbol rate Δt _compO is read by referring to the table using r _ini , extended CP symbol count S _Vini , current symbol rate r, current CP symbol count S _now (r), and extended CP symbol count Sv _now (r) as parameters. It may be.

Also, the current symbol rate r, the current number of CP symbols S _now (r), the number of extended CP symbols Sv _now (r), the symbol rate of the previous block (or the previous transmission slot), and the previous one Δt _compO was calculated in advance in accordance with each combination of the number of CP symbols of the previous block (or the previous transmission slot) and the number of extended CP symbols of the previous block (or the previous transmission slot). The values are stored in the table in association with each combination, and the current symbol rate r, the current number of CP symbols S _now (r), the number of extended CP symbols Sv _now (r), the previous block (or 1) The symbol rate of the previous transmission slot), the number of CP symbols in the previous block (or previous transmission slot), and the number of extended CP symbols in the previous block (or previous transmission slot) As table Referring may be read Delta] t _COMPO by.

(Eighth embodiment)
In this embodiment, the base station determines the transmission timing in consideration of the influence of the symbol rate in addition to the normal timing control, and notifies the terminal device of timing information (feedback information) indicating the determined transmission timing. It is characterized by. Hereinafter, this embodiment will be described in detail.

  FIG. 19 is a block diagram showing the configuration of the base station according to the eighth embodiment.

  The antenna unit 101 receives a signal transmitted from the terminal device at the time of reception, and radiates a signal input from the base station switch unit 102 to the space as a radio wave at the time of transmission. The antenna unit 101 corresponds to a receiving unit, for example.

  The switch unit 102 switches a switch so that a signal received by the antenna unit 101 is output to the LNA unit 103 during reception, and a signal input from the PA unit 122 is output to the antenna unit 101 during transmission.

  The LNA unit 103 performs low noise amplification processing on the signal input from the switch unit 102 and outputs the signal subjected to low noise amplification processing to the DC unit 104.

  The DC unit 104 down-converts the RF (Radio Frequency) signal input from the LNA unit 103 to generate an analog baseband signal, and outputs the generated analog baseband signal to the LPF unit 105.

  The LPF unit 105 performs filtering using an LPF (Low Pass Filter) to remove harmonic components from the signal input from the DC unit 104, and outputs the signal from which the harmonic components have been removed to the AD conversion unit 106. To do.

  The AD conversion unit 106 converts the analog signal input from the LPF unit 105 into a digital signal, and outputs the digital signal to the FFT unit 107.

  The FFT unit 107 performs FFT (Fast Fourier Transform) processing on the digital signal input from the AD conversion unit 106 to convert from the time domain to the frequency domain, and outputs the frequency domain signal 108 to the window function unit. The FFT unit 107 corresponds to, for example, a Fourier transform unit.

  The window function unit 108 performs window function processing on the frequency domain signal input from the FFT unit 107 to extract a signal of a desired frequency component, and the extracted desired frequency component signal is converted into an FDE (Frequency-Domain Equalization: frequency domain). (Equalization) unit 109.

  The FDE unit 109 performs frequency domain equalization processing on a desired frequency domain component signal input from the window function unit 108, and performs IFFT (Inverse Fast Fourier Transform) on the frequency domain equalized signal. Output to the unit 110.

  IFFT section 110 performs IFFT processing on the desired frequency domain component signal input from FDE section 109 to convert it into a time domain signal, and outputs the time domain signal to detection section 112 and timing error detection section 11.

  The timing error detection unit 111 detects a timing error for a desired FFT timing from the time domain signal input from the IFFT unit 110, and outputs timing error information representing the detected timing error to the detection unit 112 and the MAC unit 116. As a timing error detection method, a correlation between a known signal included in a received signal and an ideal known signal stored in advance in the timing error detection unit 111 is calculated, and the timing error is determined by the timing at which the peak of the correlation output appears. Can be detected. However, this timing error detection method is merely an example, and the present invention is not limited to this method.

  The detection unit 112 detects the time domain signal input from the IFFT unit 110 based on the timing error information input from the timing error detection unit 111, and outputs detection data to the demodulation unit 113.

  Demodulation section 113 performs demodulation processing such as soft decision processing and decoding processing on the detection data input from detection section 112 and outputs the demodulated data to MAC section 116.

  The MAC unit 116 performs processing of the MAC layer, extracts upper layer data from the demodulated data, and passes the extracted upper layer data to the upper layer unit 115. Further, the MAC unit 116 passes the timing error information received from the timing error detection unit 111 to the timing control signal generation unit 117.

  The upper layer unit 11 receives information from the MAC unit 116 at the time of reception, performs processing higher than the MAC layer, and outputs information obtained by processing at the upper layer to the MAC unit 116 at transmission.

The MAC unit 116 performs MAC layer processing on the information input from the upper layer unit 11 and outputs information to be transmitted to the modulation unit 118. Further, the MAC unit 116 outputs modulation information input from the higher layer unit 11 and notified to the terminal device to the timing control signal generation unit 117. The modulation information includes symbol rate information indicating the symbol rate to be transmitted to the terminal apparatus, CP symbol number information indicating the number of CP symbols in the block to be transmitted to the terminal apparatus, and the number of extended CP symbols in the block to be transmitted to the terminal apparatus. Information on the number of extended CP symbols.
Therefore, the upper layer unit 11 includes, for example, symbol rate notification means.

The timing control signal generation unit 117 generates timing information based on the modulation information and timing error information input from the MAC unit 116, and outputs the timing information to the modulation unit 118.
The timing control signal generation unit 117 has functions of, for example, transmission timing calculation means, transmission timing correction means, and timing information notification means.

  Modulation section 118 creates a modulation signal based on information input from MAC section 116 and timing information input from timing control signal generation section 117, and outputs the modulation signal to DA conversion section 119.

  The DA conversion unit 119 converts the digital modulation signal input from the modulation unit 118 into an analog signal, and outputs the analog signal to the LPF unit 120.

  The LPF unit 120 performs a filtering process using an LPF (Low Pass Filter) to remove the harmonic component from the analog signal input from the DA conversion unit 119, and the signal from which the harmonic component is removed is sent to the UC unit 121. Output.

  The UC unit 121 up-converts the analog baseband signal input from the LPF unit 120 to a desired RF and outputs the RF signal to the PA unit 122.

  The PA unit 122 amplifies the power of the RF signal input from the UC unit 121 and outputs the amplified signal to the switch unit 102.

  FIG. 20 is a block diagram illustrating a configuration of the timing control signal generation unit 117.

となる。ただし、S_iniは、基地局が今回のタイミング誤差検出に用いた端末装置からの送信信号のCPシンボル数、S_Viniは基地局が今回のタイミング誤差検出に用いた端末装置からの送信信号の拡張CPシンボル数、r_iniは今回のタイミング誤差検出に用いた端末装置からの送信信号のシンボルレートである。S_ini、S_Vini、r_iniと、今回入力された変調情報に基づいて差分算出部でΔt_compOを算出する。ここで得られたΔt_compOをタイミング加減算部１３２に出力する。 Difference calculation section 131 receives modulation information from MAC section 116, calculates transmission timing difference information, and outputs the calculated transmission timing difference information to timing addition / subtraction section 132. When the symbol rate to be transmitted to the terminal device is r, the number of CP symbols of the block to be transmitted to the terminal device is S _now (r), and the number of extended CP symbols of the block to be transmitted to the terminal device is S _Vnow (r), the difference calculation unit The output Δt _compO of 131 is

It becomes. Where S _ini is the number of CP symbols of the transmission signal from the terminal device used by the base station for the current timing error detection, and S _Vini is the extension of the transmission signal from the terminal device used by the base station for the current timing error detection The number of CP symbols, r _ini, is the symbol rate of the transmission signal from the terminal device used for the current timing error detection. Based on S _ini , S _Vini , r _ini and the modulation information input this time, Δt _compO is calculated by the difference calculation unit. The Δt _compO obtained here is output to the timing addition / subtraction unit 132.

The timing addition / subtraction unit 132 adds the timing error Δt _CS included in the timing error information input from the MAC unit 116 and Δt _compO input from the difference calculation unit 131, and the result Δt _out = Δt _CS + Δt _compO is output to the modulation unit 118 as timing information.

  In this way, when generating timing information to the terminal device, not only the measured timing error, but also correction considering the symbol rate update information, CP symbol count update information, and extended CP symbol count update information (for example, The transmission timing control of the terminal device can be performed efficiently by generating timing information by adding a correction according to the derivation formula.

In this embodiment, Δt _compO is calculated by the difference calculation unit 131 according to the derivation formula. However, the present invention is not limited to the calculation by the derivation formula, and for example, as described in the seventh embodiment, the derivation formula or the like is previously set The value Δt _compO calculated based on the above may be _stored in a table (memory), and Δt _compO may be obtained by referring to this table. In consideration of mounting errors and the like, a value in a range that does not deviate significantly from the value of the derived expression may be applied to the table value.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

The figure which shows the structural example of the mobile communication system which concerns on a 1st Example. The figure which shows the example of a data block. The figure which shows the example of the slot format which a terminal device transmits. The block diagram which shows the structure of a terminal device. The block diagram which shows the structure of a timing calculation part. The figure which shows the optimal FFT timing according to a symbol rate. The figure explaining the optimal FFT timing. The figure which shows transmission timing control according to a symbol rate. The block diagram which shows the structure of the terminal device which concerns on a 2nd Example. The block diagram which shows the structure of the timing calculation part which concerns on a 2nd Example. The block diagram which shows the structure of the terminal device concerning a 3rd Example. The block diagram which shows the structure of the timing calculation part concerning a 3rd Example. The block diagram which shows the structure of the timing calculation part of the terminal device which concerns on a 4th Example. The block diagram which shows the structure of the timing calculation part of the terminal device which concerns on a 5th Example. The figure explaining transmission timing control in case a terminal device transmits per slot. The figure which shows the example at the time of employ | adopting 2 symbols as extended CP. The block diagram which shows the structure of the terminal device at the time of using extended CP which concerns on a 7th Example. The block diagram which shows the structure of the timing calculation part which concerns on a 7th Example. The block diagram which shows the structure of the base station which concerns on an 8th Example. The block diagram which shows the structure of the timing control signal generation part which concerns on an 8th Example.

Explanation of symbols

PS1, PS2: Terminal equipment
CS1: Base station 11: Upper layer sections 12, 41, 43, 81: MAC section 13, 83: Modulation sections 14, 42, 44, 82: Timing calculation section 15: CP addition section 16: FIR section 17: Timing adjustment section 18: DA conversion unit 19: Low-pass filter 20: UC unit 21: PA unit 22: Switch unit 23: Antenna unit 24: LNA unit 25: DC unit 26: Low-pass filter 27: AD conversion unit 28: Demodulation units 31, 48: Base station notification timing information storage unit 32: initial symbol rate storage unit 33: symbol rate comparison units 34, 47, 132: timing addition / subtraction unit 45: previous information storage unit 51: CP symbol number storage units 46, 52, 62, 131: Difference calculation unit 61: initial timing storage unit 71, 91: timing table unit

Claims (9)

Block generating means for generating a block of a predetermined time length by adding a repetition symbol having the same waveform as a partial waveform including the other end of the plurality of symbols to one end of a plurality of temporally continuous symbols;
The higher timing earlier than the symbol rate symbol rate as a reference for the block and the lower the timing later than the symbol rate symbol rate is the reference of the blocks, by modifying the specified transmission timing of the block, Transmission timing determining means for determining a transmission timing for transmitting the block generated by the block generating means;
Transmission means for transmitting the block generated by the block generation means at the transmission timing determined by the transmission timing determination means,
Regardless of the symbol rate of each block generated by the block generation means, the time lengths of the blocks are the same, and the time lengths of the repeated symbols included in the blocks are the same. . Timing for transmitting a first signal for determining the transmission timing of the block generated by the block generation means in the base station to the base station, and acquiring timing information defining the transmission timing of the block from the base station An information acquisition means;
The transmission timing determination means determines a transmission timing earlier than the transmission timing determined by the timing information when transmitting a block having a symbol rate higher than the symbol rate of the block that transmitted the first signal, The transmission timing that is later than the transmission timing determined by the timing information is determined when a block having a symbol rate lower than the symbol rate of the block that has transmitted the first signal is transmitted. The terminal device described in 1.   The terminal apparatus according to claim 2, wherein the first signal is a dedicated signal for determining the transmission timing in the base station. When the symbol rate is changed to the second symbol rate, the transmission timing determination means is
r ₂ is the value of the second symbol rate,
S ₂ is the number of repetition symbols included in the block of the second symbol rate,
a value of the Xth symbol rate which is a symbol rate immediately before r _x is changed to the second symbol rate or a predetermined reference symbol rate;
S _x is the number of repetition symbols included in the block of the Xth symbol rate,
Then,
When (S ₂ -1) / r ₂ is larger than (S _x -1) / r _x, the transmission timing at the second symbol rate is transmitted at the symbol rate of X as the absolute value of these differences increases. Determining the transmission timing at the second symbol rate to be earlier than the timing;
When (S _x -1) / r _x is larger than (S ₂ -1) / r _2, the transmission timing at the second symbol rate increases as the absolute value of these differences increases. Determining the transmission timing at the second symbol rate to be later than the transmission timing;
The terminal device according to claim 1. Said transmission timing determining _{means, (S 2 -1) / r} 2 is (S _x -1) / r is greater than _{x is, ((S 2 -1) /} r 2 - (S x -1) / The transmission timing at which the transmission timing at the Xth symbol rate is advanced by a value based on r _x ) / 2 is determined as the transmission timing at the second symbol rate, and (S _x −1) / r _x is (S ₂ -1) / when r ₂ greater _{than, ((S x -1) /} r x - (S 2 -1) / r 2) / only value based on the second transmission at the symbol rate of the first X timing The terminal apparatus according to claim 4, wherein a transmission timing that is delayed is determined as a transmission timing at the second symbol rate. A first table that stores the S ₂ , the r _{2, the} S _x, and the r _{x in association} with the transmission timing time to be delayed or advanced;
The transmission timing determination means acquires a transmission timing time to be delayed or advanced by referring to the first table based on the S ₂ , the r _{2, the} S _x, and the r _x , and the acquired time The terminal apparatus according to claim 4, wherein the transmission timing of the block at the second symbol rate is calculated from the transmission timing at the Xth symbol rate. The Xth symbol rate is the predetermined reference symbol rate, and the S _x and the r _x are predetermined fixed values, respectively.
A second table that stores the S ₂ and the r _{2 in association} with the transmission timing time to be delayed or advanced;
The transmission timing determining means acquires the transmission timing time to be delayed or advanced by referring to the second table based on the S ₂ and the r ₂ , and acquires the acquired time and the reference transmission The terminal apparatus according to claim 4, wherein the transmission timing of the block of the second symbol rate is calculated from the timing. Receiving means for receiving, from a terminal device, a block of a predetermined time length in which a repetition symbol having the same waveform as a partial waveform including the other waveform of the plurality of symbols is added to one end of a plurality of temporally continuous symbols;
Fourier transform means for Fourier transforming the signal of the block received by the receiving means in a section corresponding to the length of the plurality of symbols;
Timing error detection means for detecting an error with respect to a desired timing of the Fourier transform of the signal of the block by the Fourier transform means;
Transmission timing calculation means for calculating a transmission timing for transmitting the block by the terminal device based on an error detected by the timing error detection means;
Symbol rate notification means for notifying the terminal device of a change in symbol rate;
When the symbol rate after the change is higher than the symbol rate of the block when the transmission timing is calculated by the transmission timing calculation means, the absolute value of the difference between the symbol rate after the change and the symbol rate of the block is large The transmission timing calculated by the transmission timing calculation means is corrected to an earlier timing,
When the symbol rate after the change is lower than the symbol rate of the block when the transmission timing is calculated by the transmission timing calculation means, the absolute value of the difference between the symbol rate after the change and the symbol rate of the block is large The transmission timing correction means for correcting the transmission timing calculated by the transmission timing calculation means to a later timing,
Timing information notifying means for notifying the terminal device of timing information representing the transmission timing corrected by the transmission timing correcting means;
With
Regardless of the change of the symbol rate of the terminal device, the time length of each block received from the terminal device by the receiving means is the same, and the time length of the repetitive symbol included in each block is respectively Base stations that are identical . A block generation step of generating a block of a predetermined time length by adding a repetition symbol having the same waveform as a partial waveform including the other end of the plurality of symbols to one end of a plurality of symbols that are temporally continuous;
The higher timing earlier than the symbol rate symbol rate as a reference for the block and the lower the timing later than the symbol rate symbol rate is the reference of the blocks, by modifying the specified transmission timing of the block, A transmission timing determination step for determining a transmission timing for transmitting the block generated by the block generation step;
A transmission step of transmitting the block generated by the block generation step at the transmission timing determined by the transmission timing determination step;
With
Regardless of the symbol rate of each block generated in the block generation step, the time length of each block is the same, and the time length of the repeated symbol included in each block is the same. .

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