Communication device and method

ES 2 396 470 T3

DESCRIPTION

SRS (Sound Reference Signals) reception

Technical field

The present invention relates to a radio communication base station apparatus and an association setting method.

Background of the technique

The LTE RAN 3GPP (Long Term Evolution) is studying the transmission of SRS (polling reference signals) for the estimation of channel quality (CQI estimation (channel quality indicator)) for frequency scheduling, uplink transmission power control and reception timing detection from a mobile radio communication station apparatus (hereinafter abbreviated as mobile station) to a radio communication base station apparatus (hereinafter abbreviated as base station) (for example, see NTT DoCoMo, Fujitsu, Mitsubishi Electric, NEC, Panasonic, Sharp, Toshiba Corporation, R1-072938, “Necessity of Multiple Bandwidths for Souding Reference Signals”, 3GPP TSG RAN WG1 Meeting # 49bis, Orlando, United States, June 25-29, 2007).

According to the LTE RAN 3GPP, for example, an SRS is formed with a LB (long block) and the time length of the SRS is 71.4 ps, including the CP (cyclic prefix) and the reference signal. Furthermore, the mobile station transmits SRSs periodically (eg, in 1-subframe = 1 ms intervals), according to the command from the base station. In addition, a plurality of bandwidths, such as 1.25 MHz, 5 MHz, and 10 MHz, are provided for the SRS transmission bandwidth, and a bandwidth corresponding to the propagation condition of the station is set. mobile. For example, a mobile station located in a dge cell where the propagation condition is poor and the transmission power is limited does not have the necessary power to transmit a wideband SRS, and for the mobile station to transmit a narrowband SRS (for example, 1.25 MHz). When using narrowband sRs, the wideband CQI estimation is carried out over a plurality of transmission time fields by performing frequency hopping.

In addition, the LTE RAN 3GPP is studying the use of random access preamble (hereinafter abbreviated as preamble) for the initial access of a mobile station, the transmission timing update and the estimation of the uplink CQI from a mobile station to a base station (for example, see Texas Instruments, R1-063213, "Improved Non-Synchronized Random Access structure for E-UTrA", 3gPP TSG RAN WG1 Meeting # 47bis, Riga, Latvia, November 6-10, 2006). A preamble is a signal that includes identifying information about a mobile station, and each mobile station randomly selects one of a plurality of code sequences established in advance by a base station or selects a code sequence according to command from the base station. Base station. Each mobile station transmits a preamble generated based on the selected code sequence to the base station. According to the LTE RAN 3GPP, the preamble is formed with a subframe, for example, and the time length of the preamble is 1 ms (= 14 LBs) including the CP, the preamble and the guard time, which is a non-transmission period. Furthermore, the mobile station transmits preambles periodically (eg at 10-subframe intervals = 10 ms intervals), according to the command from the base station as in the case of the SRS. Also, for the preamble transmission bandwidth, for example, 1.08 MHz is set (= 6 RBs (resource blocks)). In addition, when the preamble is transmitted, the frequency hopping is performed to provide a frequency diversity gain and improve the preamble detection performance, as in the case of SRS.

In addition, a preamble transmitted from a mobile station that has not established synchronization with an uplink base station involves a delay that matches the round trip propagation delay (RTD) time in the receive timing. reception on the base station. Therefore, a guard time is set in the preamble as described above to prevent the preamble from being delayed and causing interference with the signal of the next subframe.

When an SRS is transmitted, time domain and frequency domain resources can be assigned to it unique to other signals (for example, see NEC Group, NTT DoCoMo, R1-072824, "Discussion on Uplink Reference Signal", 3GPP TSG rAn WG1 Meeting # 49bis, Orlando, United States, June 25-29, 2007). Here, an SRS is assigned to the first I LB in a subframe (= 1 ms) of PUSCH (Physical Uplink Shared Channel), which is formed with 14 LBs and assigned transmission data from the mobile station, and transmitted to the base station.

Nokia et al: "UL sounding reference signal for EUTRA TDD" XP050106653 describes various aspects related to uplink in a time divisional duplex system. It is suggested that each uplink subframe should have an uplink sound capability, giving Node B the ability to adjust the periodicity of time. If the uplink S-RS is used to support the downlink transmission, the placement must be at the end of the subframe. This allows the use of a shorter delay channel in

ES 2 396 470 T3 the downlink.

Samsung: “Sounding RS Multiplexing in E-UTRA UL - Interaction with PUCCH” XP050106743 describes the transmission of downlink CQI or ACK / NAK from persistent programming, simultaneous transmissions with the SRS can be avoided due to the periodicity of this signaling. For the ACK / NAK associated with dynamic programming, there are two options. ACK / NAK transmission on a symbol is suspended, or SRS transmission is suspended. Between the two options, suspending ACK / NAK transmission on a one-slot symbol seems preferable due to the complete predictability and negligible impact of this effect.

Catt: "Uplink Souding Reference Signals for TDD with Alternative frame Structure" XP050111783 describes transmission of sound RS according to signaling from Node B for TDD with alternative frame structure and sound LB RS selection should provide more flexibility and adapt it to various application scenarios. For the sound RS bandwidth, it is proposed to support a smaller bandwidth to send sound RS for the exploitation of the channel reciprocity.

Description of the invention

Problems to be solved by the invention

However, with the conventional technique described above for performing transmission by assigning the SRS to the first LB in a subframe, the first LB in a subframe is more frequently used to transmit the SRS when the number of mobile stations in a cell increases. . That is, the proportion of the communication resources used to transmit the SRSs increases as the number of mobile stations in the cell increases. Therefore, according to the conventional technique described above, when the number of mobile stations within the cell increases, the communication resources available for data transmission decrease, and as a result, the efficiency of data transmission is reduced. reduces.

Therefore, it is an object of the present invention to provide a radio communication base station apparatus and association setting procedure capable of suppressing the amount of communication resources used for SRSs.

Means to solve the problem. This object is solved by the object of the independent claims.

According to a preferred example of the radio communication base station, it adopts a configuration that includes a reception section that receives a first signal that is provided with a guard time and that is transmitted periodically, and a second signal that is transmitted periodically. , a configuration section that establishes an association between the first signal and the second signal in such a way that a first transmission field for the first signal coincides with a second transmission field for the second signal, and a determining section that determines the second transmission field based on the first transmission field and association.

According to an embodiment of the present invention, a radio communication base station apparatus comprises a receiving section that receives a first signal that is provided with a guard time and that is periodically transmitted; a second signal that is transmitted periodically, a setting section that establishes an association between the first signal and the second signal in such a way that a first transmission field for the first signal coincides with a second transmission field for the second signal and a determining section determining the second transmission field based on the first transmission field and the association.

According to a further example of the radio communication base station apparatus, the first signal is a random access preamble and the second signal is a sound reference signal.

According to a further example, the configuration section establishes an association between a transmission interval of the first signal and a transmission interval for the second signal in such a way that the transmission time field for the first signal coincides with the time field transmission for the second signal.

According to a further example, the adjustment section establishes the association such that the transmission interval for the first signal multiplied by m (m is a positive integer) coincides with the transmission interval for the second signal multiplied by n (n is a positive integer).

According to a further example, the adjustment section establishes an association between a transmission band of the first signal and the transmission band of the second signal in such a way that the transmission band of the first signal coincides with the transmission band of the second signal.

ES 2 396 470 T3

According to a further example, the tuning section establishes the association such that a frequency hopping pattern of the first signal matches a frequency hopping pattern of the second signal in a transmission time field where the time field transmission time for the first signal matches the transmission time field for the second signal.

According to a further example, when there are a plurality of second signals in different frequency bands in the same transmission time field, the adjustment section establishes the association uniformly for each of the plurality of second signals.

According to a further example, when there are a plurality of second signals in different frequency bands in the same transmission time field, the adjustment section establishes the association for one of the plurality of second signals preferably.

According to a further example, when there are a plurality of second signals in different frequency bands of the same transmission time field, the adjustment section establishes the association for the second signal of the smallest transmission bandwidth in the plurality of second signals preferably.

According to a further example, the reception section receives the second signal arranged in the guard time in such a way that a time interval between the first signal and the second signal becomes maximum.

According to a further example, the reception section receives the second signal arranged at the beginning of the transmission time field for the first signal.

According to a further example, the reception section receives the second signal arranged at the tail end of the transmission time field of the first signal.

Furthermore, a mobile radio communication station apparatus comprises an arrangement section having a second signal that is periodically transmitted in a guard time for a first signal that is periodically transmitted in a first transmission field that coincides with a second signal transmission field and a second transmission section transmitting the second signal arranged in the guard time.

According to an example of a mobile radio communication station apparatus, the first signal is a random access preamble and the second signal is a sound reference signal.

According to an illustrative example, an association setting procedure for a radio communication base station apparatus receives a first signal that is provided with a guard time, which is transmitted periodically, and a second signal that is transmitted periodically, wherein the first signal and the second signal are associated in such a way that a transmission field for the first signal coincides with a transmission field for the second signal.

Advantageous effects of the invention

According to the present invention, the amount of communication resources used for SRSs can be reduced.

Brief Description of Drawings

Figure 1 is a block diagram illustrating a configuration of a base station according to Embodiment 1 of the present invention;

Figure 2 is a block diagram illustrating a configuration of a mobile station transmitting a preamble according to Embodiment 1 of the present invention;

Figure 3 is a block diagram illustrating a configuration of a mobile station transmitting an SRS in accordance with Embodiment 1 of the present invention;

Fig. 4 is a diagram illustrating an association of a transmission time field according to Embodiment 1 of the present invention;

Fig. 5 is a diagram illustrating a preamble transmission time field according to Embodiment 1 of the present invention;

Figure 6 is a sequence of operation of a mobile communication system according to Embodiment 1 of the present invention;

Fig. 7 is a diagram illustrating a preamble transmission time field in accordance with Embodiment 2 of the present invention;

Figure 8 is a block diagram illustrating a configuration of a base station according to Embodiment 3 of the present invention;

Fig. 9 is a diagram illustrating an association of a transmission time field in accordance with Embodiment 3 of the present invention;

Figure 10 is a diagram illustrating another association of a transmission time field of the present

ES 2 396 470 T3 invention (first association example); Y

Fig. 11 is a diagram illustrating a further association of a transmission time field of the present invention (second association example).

Best mode of carrying out the invention

Hereinafter, embodiments of the present invention will be explained in detail with reference to the accompanying drawings.

(Embodiment 1)

Figure 1 shows a configuration of base station 100 in accordance with the present embodiment. Base station 100 receives a preamble from mobile station 200 (FIG. 2), which will be described later, and receives an SRS from mobile station 300 (FIG. 3), which will be described later.

The transmission field determining section of the preamble 101 determines the time interval of the transmission time field (subframe) in which the mobile station can transmit a preamble. The preamble transmission field that determines the section 101 then produces the preamble transmission time interval determined for the section that determines the SRS transmission field 103, the control signal generation section 104 and the identification section time field 109.

The configuration section of the association rule 102 establishes rules for associating the transmission time slots for the preamble and the SRS. The association rule configuration section 102 then produces the established association rules, for the transmission field determination section of the SRS 103. The details of the association rule configuration in the rule configuration section association 102 will be described later.

The transmission field determination section of the SRS 103 determines the time interval of the transmission time field (subframe) in which the SRS can be transmitted, based on the transmission time interval of the preamble, entered from the section transmission field determination of the preamble 101 and the association rules, entered from the configuration section of the association rule 102. The SRS transmission field determination section 103 then sends the determined SRS transmission time interval for the control signal generation section 104 and the time field identification section 109. The details of the processing of the determination of the SRS transmission time field in the SRS transmission field determination section 103 will be described later.

The control signal generation section 104 generates a control signal including the preamble transmission time interval entered from the preamble transmission field determination section 101 and the SRS transmission time interval entered from the transmission field determination section of the SRS 103. The control signal generation section 104 then sends the generated control signal to the modulation section 105.

The modulation section 105 modulates the control signal 104 input from the control signal generation section and sends the modulated control signal to the radio transmission section 106.

Radio transmission section 106 performs radio processing such as D / A conversion, up to control signal conversion, and transmits the control signal to mobile station 200 and mobile station 300 through antenna 107.

On the other hand, the radio reception section 108 receives a signal transmitted from the mobile station 200 and the mobile station 300 through the antenna 107, performs radio processing such as downconversion, A / D conversion of the received signal and sends the received signal from the time field identification section 109.

The time field identification section 109 identifies the preamble transmission time field (subframe) and the SRS transmission time field (subframe) based on the preamble transmission time interval entered from the section determining the transmission field of the preamble 101 and the transmission time interval of the SRS entered from the section determining the transmission field of the SRS 103, outputs the received preamble to demodulation section 110 and the received SRS to demodulation section 112.

The demodulation section 110 demodulates the preamble input from the time field identification section 109 and outputs the demodulated preamble to the preamble detection section 111.

ES 2 396 470 T3

The preamble detection section 111 determines the correlation between the known preamble code sequence established in advance in the system and in the preamble input from the demodulation section 110, and detects the preamble. The preamble detection section 111 then outputs a preamble detection result indicating the detected preamble.

The demodulation section 112 demodulates the SRS input from the time field identification section 109 and outputs the demodulated SRS for the estimation section of the CQI 113.

The CQI estimation section 113 performs the CQI estimation based on the SRS input from the demodulation section 112. The CQI estimation section 113 then outputs the estimated value of the estimated CQI.

Next, FIG. 2 shows a configuration of mobile station 200 in accordance with the present embodiment. Mobile station 200 transmits a preamble to base station 100 (Figure 1).

Radio reception section 202 receives a control signal transmitted from base station 100 via antenna 201, performs radio processing such as down-conversion, A / D conversion on the control signal, and outputs the control signal. to demodulation section 203.

The demodulation section 203 demodulates the control signal and sends the demodulated control signal to the transmission time slot detection section 204.

The transmission time interval detection section 204 detects the preamble transmission time interval included in the control signal input from demodulation section 203 and sends the detected preamble transmission time interval to the monitoring section. generation of the preamble 205.

The preamble generation section 205 randomly selects a preamble code sequence from known preamble code sequences configured in advance in the system in the preamble transmission time field (subframe) obtained according to the time interval of preamble transmission input from transmission time slot detection section 204. The preamble generation section 205 then generates a preamble based on the selected code sequence. The preamble generation section 205 then outputs the generated preamble to the guard time aggregate section 206.

The guard time aggregate section 206 adds a guard time to a predetermined length of time to the preamble entered from the preamble generation section 205. The guard time aggregate section 206 then outputs the preamble with a guard time. to modulation section 207.

Modulation section 207 modulates the preamble and sends the modulated preamble to radio transmission section 208.

Radio transmission section 208 performs radio processing such as D / A conversion, up-conversion on the preamble input from modulation section 207, and transmits the preamble to base station 100 via antenna 201.

Next, FIG. 3 shows a mobile station 300 configuration in accordance with the present embodiment. Mobile station 300 transmits the SRS to base station 100 (Figure 1).

Radio reception section 302 receives a control signal transmitted from base station 100 via antenna 301, performs radio processing such as down-conversion and A / D conversion on the control signal, and outputs the control signal. control to demodulation section 303.

The demodulation section 303 demodulates the control signal and sends the demodulated control signal to the transmission time slot detection section 304.

The transmission time interval detection section 304 detects the transmission time interval of the SRS included in the control signal input from the demodulation section 303, and sends the transmission time interval of the detected SRS to the section. generation of the SRS 305.

The SRS generation section 305 generates a known SRS code sequence ordered from the base station 100 in advance, in the SRS transmission time field (subframe) obtained according to the transmission time interval of the SRS input from transmission time interval detection section 304. The SRS generation section 305 then sends the SRS generated by layout section 307.

ES 2 396 470 T3

The preamble transmission field information setting section 306 sets the positions and time lengths of the CP, preamble, and guard time in the preamble transmission time field. The preamble transmission field information configuration section 306 then sends the preamble transmission field information indicating the positions and time lengths of the CP, the preamble, and the guard time in the transmission time field of the preamble. preamble, to disposition section 307.

The layout section 307 sets the SRS in the preamble transmission time field (subframe) based on the preamble transmission field information input from the preamble transmission field information setting section 306. To be more specific , the layout section 307 sets the SRS at the guard time position in the preamble. For example, the layout section 307 sets the SRS at the guard time position in the preamble so that the time interval between the preamble and the SRS becomes maximum. The layout section 307 sends the arranged SRS to the modulation section 308. The details of the SRS layout that are processed in the layout section 307 will be described later.

The modulation section 308 modulates the SRS and sends the modulated SRS to the radio transmission section 309.

Radio transmission section 309 performs radio processing such as D / A conversion, upconversion into the SRS input from modulation section 308, and transmits the SRS to base station 100 via antenna 301.

Next, the details of the association rule configuration by the association rule 102 configuration section of the base station 100 (Fig. 1), the processing of determining the transmission time interval of the SRS will be explained. in the transmission field determination section of the SRS 103 and the processing of the SRS arrangement in the arrangement section 307 of the mobile station 300 (Figure

3).

To be more specific, a configuration section of the association rule 102 establishes rules according to the following equation 1.

mx (preamble transmission time interval) = nx (SRS transmission time interval) ... (Equation 1) where m and n are positive integers. That is, the configuration section of the association rule 102 configures de m and n. Hereby, the transmission time field of the preamble and the transmission time field of the SRS coincide in a transmission time field that satisfies Equation 1. That is, the preamble and the SRS use the same transmission time field.

Next, the SRS transmission field determination section 103 determines the SRS transmission time field interval according to the preamble transmission time interval input from the preamble transmission field determination section. 101 and the rules (m and n) set in the configuration section of the association rule 102. That is, the transmission field determination section of the SRS 103 determines the transmission time interval of the SRS from (m / n) x (preamble transmission time interval) based on equation 1.

This will be explained more specifically below. Here, assuming that the preamble transmission time interval determined in the preamble transmission field determination section 101 is 10 subframes, the association rule setting section 102 sets m = 1 and n = 2. On the other hand, suppose the system bandwidth is 24 RBs, the bandwidth for the preamble layout is 6 RBs, and the bandwidth for the SRS layout is 24 RBs. Also, suppose that the preamble time length is 1 subframe, and 1 subframe is 14 LBs. On the other hand, suppose the SRS duration time is 1 LB.

Hereby, the transmission field determination section field of the SRS 103 determines that the transmission time interval of the SRS is 5 subframes from (1/2) x (10 subframes).

Thus, as shown in Fig. 4, while the time interval of the preamble transmission time field is 10 subframes, the time interval of the SRS transmission time field is 5 subframes. Furthermore, the preamble transmission time field, which requires a longer SRS transmission time interval, constantly coincides with the SRS transmission time field. That is, since part of the SRS transmission time field (half of the whole in Figure 4) is transmitted using the same transmission time field as the preamble transmission time field, the communication resources used for SRS can be reduced.

ES 2 396 470 T3

When one of m and n is 1 in the above equation, the preamble transmission time field constantly matches the transmission time field of the SRS in the transmission time field for one of the preamble and the SRS having the interval of longest time of transmission time field. On the other hand, when m = n = 1, the preamble transmission time field constantly coincides with the SRS transmission time field, and consequently, the preamble transmission time field is the only resource of communication used for SRS.

On the other hand, the layout section 307 of the mobile station 300 (FIG. 3) organizes the generated SRS at the guard time position in the preamble transmission time field in such a way that the time interval between the preamble and SRS is maxed out.

To be more specific, the layout section 307 commands the SRS on the guard time of a subframe including the CP, the preamble, and the guard time, as shown in Figure 5. Here, the layout section 307 sets the SRS at the far end of the subframe such that the time interval between the preamble and the SRS becomes maximum, as shown in Figure 5.

In this case, the preamble and SRS shown in Figure 5 are transmitted from different mobile stations, mobile station 200 (Figure 2) and mobile station 300 (Figure 3). Furthermore, the uplink synchronization is established between the mobile station 300 transmitting the SRS and the base station 100, while the uplink synchronization is not established between the mobile station 200 transmitting the preamble and the base station 100. That is, since the mobile station 300 transmits the SRS taking into account the RTD between the mobile station 300 and the base station 100, the reception timing of the SRS at the base station 100 is not delayed. On the other hand, since the mobile station 200 transmits the preamble, regardless of the RTD, the reception timing of the preamble at the base station 100 is delayed by the RTD.

However, since the mobile station 300 layout section 307 arranges the SRS at the end end of the subframe in such a way that the time interval between the preamble and the SRS is maximized, even if the reception timing of the preamble that shown in Fig. 5 delay guard time, base station 100 can minimize interference between preamble and SRS. Especially when the RTD satisfies the following equation 2, there is no interference between the preamble and the SRS.

RTD <GT - (CP + SRS) ... (Equation 2) where GT is the time length of the guard time of the preamble transmission time field (subframe), CP is the CP time length of the SRS (value corresponding to delay propagation) and SRS is the time length of the SRS.

When, for example, the values ​​determined in the LTE RAN 3GPP are applied to equation 2, IDT <26 ps. In this case, suppose GT = 97.4 ps, CP = 4.8 ps, and SRS = 66.6 ps. In addition, the RTD increases by 6.67 ps each time the distance between base station 100 and mobile station 200 increases by 1 km. That is, when the distance between base station 100 and mobile station 200 is equal to or less than about 3.9 (= 26 / 6.67) kilometers, there is no interference between the preamble and the SRS shown in the figure 5.

Next, the operation of a mobile communication system formed with the base station 100, the mobile station 200 and the mobile station 300 will be explained. Fig. 6 shows an operation sequence of the mobile communication system according to the present embodiment.

In ST 101 (stage), the preamble 101 transmission field determination section of the base station 100 determines the transmission time interval of the preamble (for example, 10 sub-frames shown in Fig. 4) first and the first. SRS transmission field determination section 103 determines the SRS transmission time interval (eg, 5 subframes shown in Fig. 4). Base station 100 then transmits the preamble transmission time slot, the SRS transmission time slot to mobile station 200 and mobile station 300, respectively.

In ST 102, in the mobile station 200 that has received the preamble transmission time interval and the SRS transmission time interval, the transmission interval time detection section 204 detects the transmission time interval of the preamble and the preamble generation section 205 calculates the transmission time field of the preamble and generates a preamble. Mobile station 200 then transmits the preamble to base station 100.

Similarly, in ST 103, in the mobile station 300 that has received the preamble transmission time slot and the SRS transmission time slot, the transmission time slot detection section 304 detects the transmission time slot. SRS transmission time, and the SRS generation section 305 calculates the SRS transmission time field and generates an SRS. In addition, the layout section 307 sets the SRS at the guard time position in the transmission time field of the preamble. Mobile station 300 then transmits the SRS to base station 100.

ES 2 396 470 T3

Next, in ST 104, the base station 100 receives the preamble from the mobile station 200 and the SRS from the mobile station 300 according to the preamble transmission time interval and the SRS transmission time interval reported to mobile station 200 and mobile station 300.

Here, assuming that the transmission time interval of the SRS (transmission time interval T shown in Figure 6) is 5 subframes and the transmission time interval of the preamble (transmission time interval 2T that is shown in Figure 6) is 10 subframes, the relational equation of equation 1 above satisfies (preamble transmission time interval) = 2 χ (SRS transmission time interval). That is, while the base station receives a preamble from the mobile station 200 once, the base station receives an SRS from the mobile station 300 twice. Furthermore, the preamble transmission time field from mobile station 200 constantly coincides with the SRS transmission time field from mobile station 300. To be more specific, in the transmission time interval T (5 subframes) after the base station 100 receives the preamble from the mobile station 200 and the SRS from the mobile station 300 in ST 104, the base station 100 receives only the SRS from mobile station 300 at ST 105. Furthermore, in the additional transmission time interval T (5 subframes) after ST 105, that is, in the transmission time interval 2T (10 subframes) after ST 104, the base station 100 receives the preamble from the station mobile 200 and SRS from mobile station 300 at ST 106.

Thus, in the preamble transmission time field, not only the preamble, but also the SRS is constantly received, and therefore it is possible to reduce the communication resources to be ensured by the SRS transmission time field.

Thus, according to the present embodiment, the SRS transmission time slot is associated with the preamble transmission time slot. This allows the transmission time field of the SRS to coincide with the transmission time field of the preamble, and therefore it is possible to suppress the amount of communication resources used to transmit the SRS. Furthermore, when the SRS is arranged in the transmission time field of the preamble, the SRS is arranged in the guard time so that the time interval between the preamble and the SRS becomes maximum, and thus even When the preamble reception timing is delayed, it is possible to minimize the interference between the preamble and the SRS.

A case has been described with the present embodiment where the transmission bandwidth of the preamble (24 RBs) is different from the transmission bandwidth of the SRS (6 RBs) as shown in figure 4, but the width transmission bandwidth of the preamble can be equal to the transmission bandwidth of the SRS.

Furthermore, a case that has been described with the present embodiment where the base station transmits a control signal that includes a transmission time interval of the SRS for each mobile station, but it is not necessary to report the transmission time interval from the SRS into a control signal to each mobile station. For example, instead of reporting the SRS transmission time interval in a control signal to each mobile station, the base station may report the association rules to each mobile station. Hereby, each mobile station can calculate the transmission time interval of the SRS based on the transmission time interval of the preamble and the association rules. Furthermore, according to the present embodiment, the entire system can set the association rules in advance. Thus, the base station must report only the preamble transmission time interval to each mobile station, and thus can reduce the amount of information to report the transmission time interval of the SRS and the association rules.

Furthermore, a case with the present embodiment has been described where the preamble generation section 205 of the mobile station 200 (Figure 2) generates a preamble based on a randomly selected preamble code sequence from sequences preamble code numbers previously established by the system. However, the preamble generation section 205 may also generate a preamble based on a preamble code sequence given from the base station 100 (FIG. 1). Therefore, the base station 100 indicates the preamble code sequence to the mobile station 200, so that the preamble of the mobile station 200 does not collide with the preambles of the other mobile stations, and therefore it is possible to avoid the collision between preambles based on the same preamble code sequence.

Furthermore, the modulation section 105 (FIG. 1) of the base station 100 of the present embodiment, the modulation section 207 (FIG. 2) of the mobile station 200 and the modulation section 308 (FIG. 3) of the mobile station 300 They can perform DFT (Discrete Fourier Transform) processing, transmission and IFFT (Fast Inverse Fourier Transform) processing band allocation processing. Here, DFT processing transforms the signal from a time domain signal to a frequency domain signal. Furthermore, the transmission band allocation processing organizes the signal transformed to a frequency domain signal through the DFT processing into a predetermined transmission band. Furthermore, IFFT processing applies IFFT to the signal subjected to transmission processing band allocation to transform the signal from a frequency domain signal to a time domain signal.

Similarly, demodulation section 110 and demodulation section 112 of base station 100, demodulation section 203 of mobile station 200, and demodulation section 303 of mobile station 300

ES 2 396 470 T3 can perform FFT (Fast Fourier Transform) processing, IDFT (Inverse Discrete Fourier Transform) transmission band deallocation processing. Here, FFT processing applies FFT to the received signal to transform the signal from a time domain signal to a frequency domain signal. In addition, the transmission band deallocation processing extracts a predetermined transmission band that includes the transmitted signal from the frequency domain transformed signal. Furthermore, IDFT processing applies IDFT processing to the signal undergoing transmission band deallocation processing to transform the signal from a frequency domain signal to a time domain signal.

(Embodiment 2)

In the present embodiment, an SRS is arranged at the beginning of a preamble transmission time field.

The guard time addition section 206 (FIG. 2) of the mobile station 200 according to the present embodiment adds a guard time of equal length of time to the length of the SRS before the preamble entered from the preamble generation section 205 and also adds a guard time of a time length corresponding to (1 frame length - preamble length - SRS length) after the preamble.

On the other hand, when an SRS is set in a preamble (subframe) transmission time field, the arrangement section 307 (Fig. 3) of the mobile station 300 according to the present embodiment sets the SRS at the beginning of the transmission time field of the preamble (subframe).

This will be explained more specifically below. In this case, suppose that the preamble transmission time field is formed with 14 LBs and the SRS time duration is 1 LB as with the realization

1.

Therefore, as shown in FIG. 7, the layout section 307 sets the generated SRS at the beginning of the preamble (subframe) transmission time field. On the other hand, the mobile station 200 sets the CP and the preamble directly after the position where the SRS is set. That is, as shown in Figure 7, in mobile station 200, the CP and preamble are placed in this order from position 1 LB (i.e., the length of the SRS) from the beginning of the time field of transmission of the preamble (subframe). Furthermore, as shown in figure 7, in subframe 1, the remainder of the transmission time field other than the transmission time field in which the SRS and preamble (including the CP) are arranged, constitutes the time guard.

As described above, hereby, the SRS from the mobile station 300 is not delayed at the base station 100. Therefore, even when the base station 100 receives a signal with an interval between the SRS and the preamble as shown in Fig. 7, the SRS never slides to the rear, where the preamble is arranged, and therefore the SRS and the preamble do not interfere with each other in the same transmission time field. On the other hand, at base station 100, the preamble is delayed by the RTD. However, as shown in Figure 7, the present embodiment eliminates the interval between the SRS and the preamble and ensures a maximum guard time after the preamble. Therefore, when the RTD satisfies Equation 1, the base station 100 can avoid interference between the preamble and the next transmission time field signal (subframe) as in the case of Embodiment 1.

Thus, according to the present embodiment, the SRS is arranged at the beginning of the transmission time field of the preamble. This makes it possible to provide similar effects to Embodiment 1 and completely avoid interference between the SRS and the preamble.

(Embodiment 3)

A case has been described with Embodiment 1 where the preamble and SRS transmission time fields are made to match each other, but a case will now be explained with the present embodiment where the transmission time fields of the Preamble and SRS and transmit band are made to match each other.

This will be explained more specifically below. In the following explanations, let's assume that the preambles and SRSs are transmitted using frequency hopping.

FIG. 8 shows a base station configuration 400 in accordance with the present embodiment. In Figure 8, the same components as those in Embodiment 1 (Figure 1) will be assigned the same reference numerals, and their explanations will be omitted.

The preamble transmission field determination section 401 of the base station 400 according to the present embodiment determines a time interval (subframe) in which each mobile station can

ES 2 396 470 T3 transmit the preamble and a transmission band in which the preamble can be transmitted.

The association rule configuration section 402 establishes a rule for associating the preamble and transmission time slots of the SRS with their transmission bands. The details of the association rule configuration in the association rule configuration section 402 will be described later.

The SRS transmission field determination section 403 determines a time interval (subframe) in which the SRS can be transmitted and a transmission band in which the SRS can be transmitted, based on the preamble interval, the transmission time and the preamble transmission band entered from the preamble transmission field determination section 401 and the association rules entered from the association rule configuration section 402.

The control signal generation section 404 generates a control signal including the preamble transmission time interval and the preamble transmission band input from the preamble transmission field determining section 401 and the preamble time interval. SRS transmission and SRS transmission band input from the transmission field determination section of the SRS 403.

Besides, The time domain / frequency domain identification section 405 identifies the transmission time field and the transmission band of the preamble and the SRS based on the transmission time interval of the preamble and the preamble transmission band entered from the transmission field determination section of the preamble 401 and the transmission time interval of the SRS and the transmission band of the SRS input from the determination section of the transmission field of the SRS 403, sends the received preamble to the demodulation section 110 and the received SRS to the demodulation section 112.

Next, the details of the configuration of the association rule in the configuration section of the association rule 402 of the base station 400 (Fig. 8) and the processing of the determination of the transmission field of the SRS in the section will be explained. for determining the transmission field of the SRS 403.

In this case, the preamble transmission time interval determined in the preamble transmission field determination section 401 is assumed to be 5 subframes and the association rule configuration section 402 sets m = 1 and n = 5 On the other hand, suppose the system bandwidth is 24 RBs, the preamble transmission bandwidth is 6 RBs, and the transmission bandwidth is 6 RBs. On the other hand, the different mobile stations transmit SRS 1 and SRS 2, respectively. Also, both the preamble and the SRS are subject to frequency hopping whereby the transmission band is changed by the transmission time field.

As shown in Figure 9, the association rule configuration section 402 establishes association rules such that the preamble transmission band coincides with the SRS transmission band in a transmission time field that satisfies 1 χ (interval preamble transmission time) = 5 χ (SRS transmission time interval).

Since the preamble transmission time interval entered from the transmission field determination section of the preamble 401 is 5 subframes, the transmission field determination section of the SRS 403 determines that the transmission time interval of the SRS is 1 subframe from (m / n) x (preamble transmission time interval), based on equation 1. In addition, the SRS transmission field determination section 403 determines the transmission band in which the SRS transmission band and the preamble transmission band coincide, in a transmission time field that satisfies equation 1 .

That is, as shown in Fig. 9, the SRS is included in the preamble part in the preamble transmission time field. Hereby, the preamble transmission band can include the preamble and the SRS in the preamble transmission time field, and therefore it is possible to allocate the remaining transmission band, for example, to PUSCH, for the transmission of data.

Thus, according to the present embodiment, when a preamble and an SRS are frequency hopped, the transmission band of the preamble and the transmission band of the SRS are made to coincide with each other. This makes it possible to maintain the effect of frequency diversity through frequency hopping and to transmit an SRS in the same transmission time field and in the same transmission band as those of a preamble. Therefore, the present embodiment can reduce the communication resources used for SRS.

A case with the present embodiment has been described, where the transmission band of the SRS is determined in such a way that the frequency hopping pattern of the SRS coincides with the frequency hopping pattern of the preamble in a time field. in which the preamble and the SRS coincide with each other. However, according to the present invention, the transmission band of the preamble can be determined such that the frequency hopping pattern of the preamble matches the frequency hopping pattern of the SRS.

ES 2 396 470 T3

Furthermore, a case that has been described with the present embodiment where there is an SRS in the transmission time field in which the preamble and the SRS coincide with each other, but the present invention is also applicable to a case of a where there are a plurality of SRSs in the transmission time field in which the preamble and the SRS coincide with each other. For example, as shown in Figure 10, when SRS 1 and SRS 2 are arranged in different transmission bands in the same transmission time field, a transmission band that coincides with that of the preamble can be given to the SRS 1 and sRs 2 uniformly. To be more specific, as shown in Fig. 10, in the preamble transmission time field, both SRS 1 and SRS 2 transmission bands are made to pair two different preamble transmission bands, respectively. This allows the effect of the present invention resulting from the coincidence between the transmission fields of the preamble and the SRS to be given to a plurality of SRSs uniformly. On the other hand, the interference influence resulting from the coincidence between the transmission fields of the preamble and the SRS can also be uniformly distributed over a plurality of SRSs.

Furthermore, when there are a plurality of SRSs in the transmission time field in which the preamble and the SRS coincide with each other, a transmission field that coincides with that of the preamble can preferably be assigned only to a specific SRS. For example, as shown in figure 11, the SRS having the smallest transmission bandwidth (SRS 1 is shown in figure 11) of a plurality of SRSs (SRS 1 and SRS 2 shown in figure 11) can be designated as a specific SRS. Thus, for an SRS having a small transmission bandwidth (narrow band SRS), it is possible to improve the precision of the CQI estimation by using a preamble as an SRS. For example, SRS 1 can be assigned to a mobile station located at a cell edge, which has a small system bandwidth and requires an improvement in the precision of the CQI estimation. Here, when a preamble is used as an SRS, the base station indicates the code sequence that is used as a preamble to the mobile station in advance. This eliminates collision between the preambles of different mobile stations at the base station and allows the base station to use preambles in the same way as SRSs to be subjected to CQI estimation.

The embodiments of the present invention have been explained so far.

In the above embodiments, a preamble is associated with an SRS using equation 1. However, with the present invention it is equally possible to associate a preamble with an SRS by making m and n in the following equation 1 unequal. For example, the relationship m <n can assume between m and n in equation 1. That is, a preamble and the SRS can be associated to constantly satisfy the relationship: preamble transmission time interval> SRS transmission time interval.

Furthermore, the association rules in the above embodiments can be changed according to the bandwidth of the system. For example, the LTE RAN 3GPP is studying 1.25 / 2.5 / 5/10/15/20 MHz for the system bandwidth. Therefore, the SRS preamble and association rules can be changed for each of the system bandwidths described above. This allows the speed at which the preamble and SRS transmission fields coincide with each other to be set to an optimal speed for each system bandwidth. Here, the lower the bandwidth of the system, the smaller the amount of communication resources available. Therefore, by increasing the speed at which the preamble and SRS transmission time fields coincide with each other when the system bandwidth decreases, it is possible to provide a greater effect of reducing communication resources. of the SRS.

Furthermore, the above embodiments may adopt a configuration to determine whether or not to transmit the SRS in the transmission field of the preamble according to the radius of the cell and the frequency with which the SRS is transmitted. Especially, the application of the present invention is only a case where the cell radius is small which allows transmission and reception without interference between the preambles and the SRSs. Here, the cell of a small cell radius refers to a cell that satisfies the following equation 3.

Max. RTD &lt;GT - (CP + SRS) (Equation 3) where Max. RTD denotes the maximum RTD of the cell.

Furthermore, the above embodiments may also adopt a configuration in which the mobile station determines whether or not an SRS is transmitted in the preamble transmission time field according to the distance between the base station and the mobile station estimated from a level of path loss of a received signal. For example, when the distance between the base station and the mobile station is small, the mobile station transmits an SRS in the transmission time field of the preamble. This allows the base station to avoid interference between the preamble and the SRS. On the other hand, when the distance between the base station and the mobile station is large, the mobile station does not transmit any SRS in the transmission time field of the preamble. This allows the preamble to be transmitted without interference in the preamble transmission time field. In this case, even if the mobile station does not transmit any SRS, the base station may judge that the channel quality (CQI) is very low because the distance between the base station and the mobile station is large. This makes the CQI estimation unnecessary, preventing the frequency scheduling using the estimated CQI values ​​from being affected.

ES 2 396 470 T3

Furthermore, a case has been described above in which the above embodiments where a preamble and an SRS are transmitted from different mobile stations, but when the preamble and the SRS have the same time transmission field from a mobile station, the preamble and the SRS can be broadcast simultaneously. For example, the mobile station can arrange an SRS in a guard time of a preamble to be transmitted in the preamble transmission field that coincides with the transmission field of the SRS and simultaneously transmit the preamble and the SRS arranged in time. guardian of the preamble.

Furthermore, in the above embodiments, code sequences that have a small cross-correlation between a code sequence that is used as a preamble and a code sequence that is used as an SRS can be used. This allows the base station to reduce interference between the preamble and the SRS caused by a delay in the reception timing of the preamble.

Furthermore, a case that has been described with the present embodiment where a preamble is transmitted, but similar effects can also be obtained by applying the present invention to a signal with a guard time setting in the time field of transmitted and periodically transmitted by the mobile station to the base station.

Furthermore, a case that has been described with the present embodiment where an SRS is transmitted, but similar effects can also be obtained by applying the present invention to the signals periodically transmitted from the mobile station to the base station.

Furthermore, although cases with the above embodiments have been described, where the present invention is configured by hardware, the present invention can be implemented by software.

Each function block employed in the description of the aforementioned embodiments can typically be implemented as an LSI made up of an integrated circuit. These can be individual chips or partially or totally contained in a single chip. LSI has been adopted here, but this can also be referred to as IC, system LSI, super LSI or ultra LSI depending on the different extensions of the integration.

Furthermore, the circuit integration procedure is not limited to LSI, and the application using a dedicated circuit or general-purpose processors is also possible. After LSI manufacturing, the use of an FPGA (Field Programmable Gate Array) or a reconfigurable processor where connections and cell configurations within an LSI circuit can be reconfigured is also possible.

Furthermore, if integrated circuit technology comes to replace LSI as a result of the advancement of semiconductor technology or a derivative of other technology, it is naturally also possible to carry out block function integration using this technology. The application of biotechnology is also possible.

Industrial applicability

The present invention is applicable to a mobile communication system or the like.