JP5107406B2 - User equipment - Google Patents

Description

  The present invention relates to a mobile communication system to which orthogonal frequency division multiplexing OFDM (Orthogonal Frequency Division Multiplexing) is applied in the downlink, and more particularly to a base station apparatus.

  A communication method succeeding W-CDMA and HSDPA (generic name UMTS), that is, LTE (Long Term Evolution) has been studied by the UMTS standardization organization 3GPP. As for the uplink, SC-FDMA (Single-Carrier Frequency Multiple Access) has been studied (for example, see Non-Patent Document 1).

  LTE presupposes a maximum transmission rate of 100 Mbps on the downlink. In addition, it is demanded that optimization is performed for both low-speed moving terminals and high-speed moving terminals.

  In MIMO transmission, different signals are transmitted in parallel on a transmission path formed by a plurality of inputs (transmitting antennas) and a plurality of outputs (receiving antennas) (MIMO multiplexing). Despite using the same frequency, it is possible to increase the speed by the number of parallel transmission lines, which is considered to be an essential technology for LTE.

  As a radio access method, OFDM (Orthogonal Frequency Division Multiplexing) is suitable for high-speed transmission exceeding several tens of Mbps. OFDM utilizes frequency orthogonality and is arranged with high density so that subcarrier spectra overlap each other, thereby improving frequency utilization efficiency. Since the signal is divided into a plurality of subcarriers and conveyed, the symbol length is n times as long as transmission using n subcarriers (n is an integer of n> 0) compared to a system in which a signal is transmitted by one carrier. become.

  For example, as shown in FIG. 1, in a base station apparatus (eNB: eNodeB) having four antennas, a shared data channel (SDCH) is transmitted using four antennas, and an L1 / L2 control channel ( L1 / L2 control channel) is being studied for transmission with two antennas. In such a base station apparatus, a reference signal (RS: Reference Signal) specific to the antenna is transmitted from each antenna. The reference signal is a signal whose bit values transmitted and received on the transmission side and the reception side are known before communication, and is also called a known signal, pilot signal, reference signal, training signal, or the like.

  Further, in a base station apparatus having four antennas, as shown in FIG. 2, it is considered that a reference signal corresponding to each antenna is mapped to the first OFDM symbol of each transmission slot (for example, Non-patent document 2).

3GPP TR 25.814 (V7.0.0), "Physical Layer Aspects for Evolved UTRA," June 2006 3GPP TS 36.211 (V0.3.0), January 2007

  However, the background art described above has the following problems.

  In the base station apparatus, it is considered that the L1 / L2 control channel is mapped within 3 symbols (OFDM symbols) of each subframe and transmitted using two antennas. Broadcast channels (BCH: Broadcast Channel), paging channels (PCH: Paging Channel), and synchronization channels (SCH: Synchronization Channel) are considered to be transmitted from a maximum of two antennas.

  On the other hand, at least, the user terminal is required to receive the L1 / L2 control channel with one or two antennas. Therefore, when the reference signal corresponding to each antenna is mapped to the first OFDM symbol, the option of demodulation processing on the user terminal side increases. That is, it is necessary to prepare three types of demodulation processing patterns for transmission with one antenna, transmission with two antennas, and transmission with four antennas.

The present invention has been made to solve the above-described problems of the prior art, and it is an object of the present invention to reduce a demodulation processing pattern when a user apparatus receives an L1 / L2 control channel .

This user device
A user apparatus that communicates with a base station apparatus equipped with a plurality of antennas,
One subframe is composed of a plurality of slots, and one slot is composed of a plurality of basic time units.
L1 / L2 control that is a first reference signal used for demodulation of an L1 / L2 control channel and a data channel transmitted from a predetermined antenna and is mapped within a predetermined basic time unit from the head of each subframe A first receiver for receiving a channel and a first reference signal;
A second reference signal used for demodulation of a data channel transmitted from an antenna other than the predetermined antenna, and a basic time after a basic time unit to which the L1 / L2 control channel and the first reference signal are mapped A second receiver for receiving a second reference signal mapped to the unit;
Is provided.

According to the embodiment of the present invention, it is possible to reduce the demodulation processing pattern when the user apparatus receives the L1 / L2 control channel .

It is explanatory drawing which shows the transmission method of the L1 / L2 control channel and shared data channel in a base station apparatus provided with four antennas. It is explanatory drawing which shows an example of the mapping of a reference signal. It is a block diagram which shows the structure of the radio | wireless communications system based on the Example of this invention. It is a partial block diagram which shows the base station apparatus which concerns on one Example of this invention. It is a partial block diagram which shows the user apparatus which concerns on one Example of this invention. It is explanatory drawing which shows an example of the mapping of the reference signal which concerns on one Example of this invention. It is explanatory drawing which shows an example of the mapping of the reference signal which concerns on one Example of this invention.

Next, the best mode for carrying out the present invention will be described based on the following embodiments with reference to the drawings.
In all the drawings for explaining the embodiments, the same reference numerals are used for those having the same function, and repeated explanation is omitted.

  A radio communication system to which a base station apparatus according to an embodiment of the present invention is applied will be described with reference to FIG.

The wireless communication system 1000 is a system to which, for example, Evolved UTRA and UTRAN (also known as LTE (Long Term Evolution) or Super 3G) is applied, and a base station apparatus (eNB: eNode B) 200 and a plurality of user apparatuses ( UE: User Equipment) 100 _n (100 ₁ , 100 ₂ , 100 ₃ ,... 100 _n , where n is an integer of n> 0). Base station apparatus 200 is connected to an upper station, for example, access gateway apparatus 300, and access gateway apparatus 300 is connected to core network 400. Although only one antenna is illustrated in FIG. 3, the base station apparatus 200 includes a plurality of antennas. Here, the user apparatus 100 _n communicates with the base station apparatus 200 by the Evolved UTRA and UTRAN in the cell 50.

Hereinafter, since the user apparatus 100 _n (100 ₁ , 100 ₂ , 100 ₃ ,... 100 _n ) has the same configuration, function, and state, the following description is given as the user apparatus 100 _n unless otherwise specified. To proceed.

  Radio communication system 1000 employs OFDM (frequency division multiple access) for the downlink and SC-FDMA (single carrier frequency division multiple access) for the uplink as the radio access scheme. As described above, OFDM is a scheme in which a frequency band is divided into a plurality of narrow frequency bands (subcarriers) and data is transmitted on each frequency band. SC-FDMA is a transmission method that can reduce interference between terminals by dividing a frequency band and performing transmission using different frequency bands among a plurality of terminals.

  Here, a communication channel in LTE will be described.

For the downlink, a downlink shared physical channel (PDSCH) shared by each user apparatus 100 _n and a downlink control channel for LTE are used. In the downlink, the user information and transport format information mapped to the downlink shared physical channel, the user information mapped to the uplink shared physical channel, the transport format information, and the uplink shared by the downlink control channel for LTE The delivery confirmation information of the physical channel is notified, and user data is transmitted through the downlink shared physical channel.

For the uplink, an uplink shared physical channel (PUSCH) shared by each user apparatus 100 _n and an uplink control channel for LTE are used. There are two types of uplink control channels: channels that are time-multiplexed with uplink shared physical channels and channels that are frequency-multiplexed.

  In the uplink, downlink for use in scheduling of the shared physical channel in the downlink, adaptive modulation and coding (AMC: Adaptive Modulation and Coding), and transmission power control (TPC: Transmit Power Control) by the uplink control channel for LTE. Link quality information (CQI: Channel Quality Indicator) and downlink shared physical channel acknowledgment information (HARQ ACK information) are transmitted. Also, user data is transmitted through the uplink shared physical channel.

  Next, the base station apparatus 200 according to an embodiment of the present invention is described with reference to FIG. In the present embodiment, a case where the base station apparatus includes four antennas will be described, but the present invention can also be applied to a case where there are four or more antennas. In this embodiment, one subframe is composed of a plurality of slots, for example, two slots, and one slot is composed of a plurality of basic time units (basic time units), for example, seven basic time units. Although the case where it comprises is demonstrated, these conditions can be changed suitably. In the present embodiment, an area composed of one subcarrier and one basic time unit is referred to as one resource element.

The base station apparatus 200 according to the present embodiment includes a multiplexing unit (MUX) 202 ₁ , 202 ₂ , 202 ₃ and 202 ₄ , a fast inverse Fourier transform unit (IFFT) 204 ₁ , 204 ₂ , 204 ₃ and 204 ₄ , Guard interval insertion units (CP) 206 ₁ , 206 ₂ , 206 ₃ and 206 _4, and a scheduler 208 are provided.

Antenna # 1 L1 / L2 control channel # 1 transmitted from the data channel, for example, a shared data channel # 1 and the reference signal (RS) # 1 is input to the multiplexing unit 202 ₁ is multiplexed. Reference signal # 1 is used for demodulation of L1 / L2 control channel # 1 and data channel # 1. For example, as shown in FIG. 6, the L1 / L2 control channel # 1 is mapped within a predetermined OFDM symbol determined from the beginning in each subframe, for example, within the third basic time unit. In other words, the L1 / L2 control channel # 1 is mapped to a predetermined resource element determined in advance among the resource elements within the third from the head in each subframe.

Also, the reference signal # 1 is mapped within a predetermined OFDM symbol determined in advance from the top in each slot, for example, within the third basic time unit. For example, the reference signal # 1 is mapped to a predetermined resource element determined in advance among the top resource elements in each slot. Further, the reference signal # 1 is mapped to the fourth and subsequent OFDM symbols from the top in each slot. For example, the reference signal # 1 is mapped to a predetermined resource element determined in advance among the fifth resource elements from the top in each slot. From the viewpoint of improving channel estimation accuracy in the user apparatus 100 _n, the reference signal # 1 mapped to the fourth and subsequent OFDM symbols from the top in each slot may be mapped to resource elements near the center in each slot. preferable. For example, the reference signal # 1 is mapped to the 4-5th resource element from the top in each slot.

  The data channel # 1 is mapped to a resource element other than the resource element to which the L1 / L2 control channel # 1 and the reference signal # 1 are mapped.

In multiplexing section 202 _1, L1 / L2 control channel # 1, the reference signal # 1 and the data channel # 1 is mapped, multiplexed signal is input to the IFFT unit 204 _1, a fast inverse Fourier transform, the OFDM scheme Modulation is performed.

The modulated symbols is performed in the OFDM scheme, the guard interval insertion unit 206 ₁ attaches guard intervals is transmitted.

Antenna # 2 is the L1 / L2 control channel # 2 transmitted from the data channel, for example, a shared data channel # 2 and reference signal (RS) # 2 are input to the multiplexing unit 202 ₂ are multiplexed. Reference signal # 2 is used for demodulation of L1 / L2 control channel # 2 and data channel # 2. For example, as shown in FIG. 6, the L1 / L2 control channel # 2 is mapped within a predetermined OFDM symbol determined from the beginning in each subframe, for example, within the third basic time unit. In other words, the L1 / L2 control channel # 2 is mapped to a predetermined resource element determined in advance among resource elements within the third from the head in each subframe.

Further, the reference signal # 2 is mapped within a predetermined OFDM symbol determined in advance from the top in each slot, for example, within the third basic time unit. For example, the reference signal # 2 is mapped to a predetermined resource element determined in advance among the first resource elements in each slot. Further, the reference signal # 2 is mapped to the fourth and subsequent OFDM symbols from the top in each slot. For example, the reference signal # 2 is mapped to a predetermined resource element determined in advance among the fifth resource elements from the top in each slot. From the viewpoint of improving channel estimation accuracy in the user apparatus 100 _n, it is preferable that the reference signal # 2 mapped to the fourth and subsequent OFDM symbols from each head in each slot is mapped to a resource element near the center in each slot. . For example, the reference signal # 2 is mapped to the 4-5th resource element from the top in each slot.

  The data channel # 2 is mapped to a resource element other than the resource element to which the L1 / L2 control channel # 1 and the reference signal # 2 are mapped.

In multiplexing section 202 _2, L1 / L2 control channel # 2, the reference signal # 2 and the data channel # 2 is mapped, multiplexed signal is input to the IFFT unit _2042, the inverse fast Fourier transform, the OFDM scheme Modulation is performed.

The modulated symbols is performed in the OFDM scheme, the guard interval insertion unit 206 ₂ attaches guard intervals is transmitted.

Data channel transmitted from the antenna # 3, for example, a shared data channel # 3 and a reference signal (RS) # 3 are input to the multiplexing unit 202 _3, it is multiplexed. Reference signal # 3 is used for demodulation of data channel # 3. For example, as shown in FIG. 6, the reference signal # 3 each slot, basic to the L1 / L2 control channel # 1 and # 2 in the multiplexing unit 202 ₁ and 202 _2, the reference signal # 1 and # 2 are mapped It is mapped to the basic time unit after the time unit. That is, the L1 / L2 control channel is mapped to a region other than the region to which the L1 / L2 control channel is mapped, for example, the fourth and subsequent OFDM symbols from the top in each slot, that is, the basic time unit. For example, the reference signal # 3 is mapped to a predetermined resource element determined in advance among the fourth and subsequent resource elements from the top in each slot. From the viewpoint of improving the channel estimation accuracy in the user apparatus 100 _n, the reference signal # 3 mapped to the fourth and subsequent basic time units in each slot may be mapped to a resource element near the center in each slot. preferable. For example, the reference signal # 3 is mapped to the 4-5th resource element from the top in each slot.

  Data channel # 3 is mapped to a resource element other than the resource element to which resource block # 3 is mapped.

In multiplexing section _2023, the reference signal # 3 and the data channel # 3 is mapped, multiplexed signal is input to the IFFT unit 204 _3, a inverse fast Fourier transform, OFDM modulation is carried out.

The modulated symbols is performed in the OFDM scheme, the guard interval inserting unit 206 ₃ attaches guard intervals is transmitted.

Data channel transmitted from the antenna # 4, the shared data channel # 4 and a reference signal (RS) # 4 for example is input to the multiplexing unit 202 _4, are multiplexed. Reference signal # 4 is used for demodulation of data channel # 4. For example, as shown in FIG. 6, the reference signal # 4 is in each slot, basic to the L1 / L2 control channel # 1 and # 2 in the multiplexing unit 202 ₁ and 202 _2, the reference signal # 1 and # 2 are mapped It is mapped to the basic time unit after the time unit.

That is, the L1 / L2 control channel is mapped to a region other than the region to which the L1 / L2 control channel is mapped, for example, the fourth and subsequent OFDM symbols from the top in each slot, that is, the basic time unit. For example, the reference signal # 4 is mapped to a predetermined resource element determined in advance among the fourth and subsequent resource elements from the top in each slot. From the viewpoint of improving channel estimation accuracy in the user apparatus 100 _n, the reference signal # 4 mapped to the fourth and subsequent basic time units in each slot may be mapped to a resource element near the center in each slot. preferable. For example, the reference signal # 4 is mapped to the 4-5th resource element from the top in each slot.

  Data # 4 is mapped to a resource element other than the resource element to which resource block # 4 is mapped.

In multiplexing section 202 _4, mapped reference signal # 4 and data # 4 is multiplexed signal is input to the IFFT unit 204 _4, a inverse fast Fourier transform, OFDM modulation is carried out.

The modulated symbols is performed in the OFDM scheme, the guard interval insertion unit 206 ₄ attaches guard intervals is transmitted.

The scheduler 208 performs scheduling for the multiplexing units 202 ₃ and 202 _{4 so} that the reference signal # 3 and the reference signal # 4 are mapped to a region other than the region to which the L1 / L2 control channel is mapped in each slot. Do. For example, the scheduler 208 maps to the fourth and subsequent OFDM symbols from the top in each slot.

In the embodiment described above, the multiplexing units 202 ₁ , 202 ₂ , 202 ₃ and 202 ₄ map the L1 / L2 control channel and the reference signal to different resource elements with a predetermined period, for example, a subframe as a period. May be. For example, when the subframe changes, the multiplexing units 202 ₁ , 202 ₂ , 202 _3, and 202 ₄ cause the adjacent resource elements to hop and map to the adjacent resource elements.

Further, the multiplexing units 202 ₃ and 202 ₄ transmit the reference signals # 3 and # 4 for each resource block according to the number of antennas included in the user apparatus 100 _n , and the L1 / L2 control channel in the multiplexing units 202 ₁ and 202 ₂ . You may make it map to the basic time unit after the basic time unit to which # 1 and # 2 and reference signal # 1 and # 2 are mapped. For example, as illustrated in FIG. 7, when the user apparatus # 1 includes four antennas, the reference blocks # 1, # 2, # 3, and # 4 are used in the resource block allocated to the user apparatus # 1. Are mapped and the user apparatus # 2 includes two antennas, the reference signals # 1 and # 2 are mapped in the resource block allocated to the user apparatus # 2.

Next, the user apparatus 100 _n according to _an embodiment of the present invention will be described with reference to FIG.

The user apparatus 100 _{n according} to the present embodiment includes a CP removing unit 102, a fast Fourier transform (FFT) unit 104, an L1 / L2 control channel receiving unit 106, and a data receiving unit 118.

L1 / L2 control channel receiving unit 106 includes a switching unit 108 and 116, a separation unit (DEMUX) 110, a channel estimation unit 112 ₁ and 112 _2, and a demodulator 114.

The data receiving unit 118 includes switching units 120 and 128, a demultiplexing unit (DEMUX) 122, channel estimation units 124 ₁ , 124 ₂ , 124 ₃ and 124 _4, and a signal demultiplexing / demodulating unit 126.

  CP removing section 102 removes the guard interval from the received symbol and leaves the effective symbol portion.

  A fast Fourier transform unit (FFT) 104 performs fast Fourier transform on the input signal. The fast Fourier transformed signal is input to the switching unit 108 or 120. The L1 / L2 control channel is input to the switching unit 108 and the data channel is input to the switching unit 120.

Switching unit 108 determines whether base station apparatus 200 transmits the L1 / L2 control channel using one antenna or two antennas, that is, depending on the number of antennas transmitting the L1 / L2 control channel. Switch to demodulation processing or demodulation processing during 2-antenna transmission. For example, the user apparatus 100 _n notifies the number of antennas included in the own user apparatus 100 _n in the connection process with the base station apparatus 200.

Base station apparatus 200 determines the number of antennas that transmit the L1 / L2 control channel according to the notified number of antennas. For example, to determine that the number of antennas provided in the user apparatus 100 _n transmits on one antenna in the case of one, two, if the number of antennas provided in the user apparatus 100 _n is not less than two Decide to transmit by antenna. In addition, the switching unit 108 inputs the switching result to the demodulation process at the time of one antenna transmission or the demodulation process at the time of two antenna transmission to the switching unit 116.

When the base station apparatus 200 transmits the L1 / L2 control channel with one antenna, the fast Fourier transformed signal is input to the signal separation unit 110 (1). The signal separation unit 110, an input signal is separated into a reference signal (RS) # 1 and L1 / L2 control channel, inputs the RS # 1 to the channel estimation unit 112 _1, the L1 / L2 control channel demodulation unit 114 input. In the channel estimation unit 112 ₁ performs channel estimation based on the RS # 1, the result of the channel estimation is input to the demodulator 114. The demodulating unit 114 demodulates the L1 / L2 control channel using the input channel estimation result, and the demodulated L1 / L2 control channel is input to the switching unit 116.

When the base station apparatus 200 transmits the L1 / L2 control channel with two antennas, the fast Fourier transformed signal is input to the signal separation unit 110 (2). The signal separation unit 110 separates the input signal into a reference signal (RS) # 1, a reference signal (RS) # 2, and an L1 / L2 control channel, and RS # 1 and RS # 2 are respectively channel estimation units. 112 type ₁ and 112 _2, and inputs the L1 / L2 control channel demodulation unit 114. In the channel estimation unit 112 _1, is performed channel estimation using the RS # 1, the channel estimation unit 112 _2, is performed channel estimation using the RS # 2, the results of their channel estimation input to the demodulator 114 Is done. The demodulator 114 separates the input L1 / L2 control channel for each antenna, and uses the input channel estimation result to demodulate the L1 / L2 control channel. The demodulated L1 for each antenna is demodulated. The / L2 control channel is input to the switching unit 116.

  In accordance with the switching result input by the switching unit 108, the switching unit 116 receives the L1 / L2 control channel demodulated by the demodulation process at the time of one-antenna transmission or the antennas demodulated by the demodulation process at the time of two-antenna transmission. L1 / L2 control channels are output.

  Switching section 120 switches to demodulation processing at the time of one antenna transmission, demodulation processing at the time of two antenna transmission, or demodulation processing at the time of four antenna transmission according to the number of antennas that base station apparatus 200 transmits data channels. Further, the switching unit 108 inputs to the switching unit 128 the result of switching to demodulation processing at the time of 1 antenna transmission, demodulation processing at the time of 2 antenna transmission, or demodulation processing at the time of 4 antenna transmission.

When the base station apparatus 200 transmits the data channel with one antenna, the fast Fourier transformed signal is input to the signal separation unit 122 (1). The signal separation unit 122, an input signal is separated into a reference signal (RS) # 1 and the data channel, inputs the RS # 1 to the channel estimation unit 124 _1, inputs the data channel to the signal separating and modulating unit 126. Channel estimation section 124 ₁ performs channel estimation using RS # 1, and the channel estimation result is input to signal separation / demodulation section 126. The signal separation / demodulation unit 126 demodulates the data channel using the input channel estimation result, and the demodulated data channel is input to the switching unit 128.

When the base station apparatus 200 transmits a data channel with two antennas, the fast Fourier transformed signal is input to the signal separation unit 122 (2). The signal separation unit 122, an input signal, a reference signal (RS) # 1 and # 2, separates the data channel, RS # 1 and inputs to the channel estimation unit 124 _1, RS # 2 to the channel estimation unit 124 ₂ And the data channel is input to the signal separation / demodulation unit 126. Channel estimation section 124 ₁ performs channel estimation using RS # 1, and the channel estimation result is input to signal separation / demodulation section 126. The channel estimation unit 124 ₂ performs channel estimation based on the RS # 2, the result of the channel estimation is input to the signal separating and modulating unit 126. In the signal separation / demodulation unit 126, the input data channel is separated for each antenna, the data channel is demodulated using the input channel estimation result, and the demodulated data channel for each antenna is switched to the switching unit. 128 is input.

When the base station apparatus 200 transmits a data channel with four antennas, the fast Fourier transformed signal is input to the signal separation unit 122 (3). The signal separation unit 110, an input signal, the reference signal (RS) # 1, # 2, separated into # 3 and # 4 and the data channel, inputs the RS # 1 to the channel estimation unit 124 _1, the RS # 2 and input to the channel estimation unit 124 _2, and inputs the RS # 3 to the channel estimation unit 124 _3, enter the RS # 4 to the channel estimation unit 124 _4, and inputs the data channel to the signal separating and modulating unit 126.

Channel estimation section 124 ₁ performs channel estimation using RS # 1, and the channel estimation result is input to signal separation / demodulation section 126. The channel estimation unit 124 ₂ performs channel estimation based on the RS # 2, the result of the channel estimation is input to the signal separating and modulating unit 126. In the channel estimation unit 124 ₃ RS # 3 channel estimation using is performed, the result of the channel estimation is input to the signal separating and modulating unit 126. The channel estimation unit 124 ₄ performs channel estimation based on the RS # 4, the result of the channel estimation is input to the signal separating and modulating unit 126. In the signal separation / demodulation unit 126, the input data channel is separated for each antenna, the data channel is demodulated using the input channel estimation result, and the demodulated data channel for each antenna is switched to the switching unit. 128 is input.

  According to the switching result input by the switching unit 120, the switching unit 128 receives the data demodulated by the demodulation processing at the time of transmission of one antenna, the data for each antenna demodulated by the demodulation processing at the time of transmission of two antennas, or 4 Data for each antenna demodulated by demodulation processing at the time of antenna transmission is output.

  According to the embodiment of the present invention, since it is not necessary to prepare a demodulation processing pattern in the case of transmitting with four antennas to the user apparatus, the reception processing can be simplified.

  The following items are further disclosed regarding the embodiment including the above examples.

(1) A base station apparatus that includes a plurality of antennas and communicates with a user apparatus through the plurality of antennas:
One subframe is composed of a plurality of slots, and one slot is composed of a plurality of basic time units.
First mapping means for mapping a reference signal used for demodulation of an L1 / L2 control channel and a data channel transmitted from a predetermined antenna within a predetermined basic time unit from the head of each subframe;
A reference signal used for demodulation of a data channel transmitted from an antenna other than the predetermined antenna is a basic signal after a basic time unit to which a reference signal used for demodulation of the L1 / L2 control channel and the data channel is mapped. A second mapping means for mapping to time units;
Is provided.

  With this configuration, it is possible to reduce demodulating options on the user terminal side.

(2) In the base station apparatus described in (1):
The first mapping means maps the reference signals used for demodulation of the L1 / L2 control channel and the data channel transmitted from two antennas within 3 basic time units from the head of each subframe.

(3) In the base station apparatus described in (1) or (2):
The second mapping means maps a reference signal used for demodulation of a data channel transmitted from an antenna other than the predetermined antenna to a basic time unit near the center of each slot.

(4) In the base station apparatus according to any one of (1) to (3):
One resource element is composed of one subcarrier and one basic time unit,
The first mapping means transmits a reference signal used for demodulation of the L1 / L2 control channel and the data channel transmitted from two antennas among resource elements within three basic time units from the head of each subframe. , Map to a predetermined resource element,
The second mapping means maps a reference signal used for demodulation of a data channel transmitted from an antenna other than the predetermined antenna to a reference signal used for demodulation of the L1 / L2 control channel and the data channel. Among the resource elements included in the basic time unit after the basic time unit to be mapped to a predetermined resource element determined in advance.

(5) In the base station apparatus described in (4):
The first mapping means maps a reference signal used for demodulation of the L1 / L2 control channel and the data channel to different resource elements at a predetermined period;
The second mapping means maps a reference signal used for demodulation of the data channel to a different resource element at a predetermined period.

(6) In the base station apparatus described in (5):
The predetermined period is a subframe.

(7) In the base station apparatus according to any one of (1) to (6):
According to the number of antennas included in the user apparatus, the second mapping unit may convert, for each resource block, a reference signal used for demodulation of a data channel transmitted from an antenna other than the predetermined antenna to the L1 / L2 The reference signal used for demodulation of the control channel and the data channel is mapped to a basic time unit after the basic time unit to which the reference signal is mapped.

50 cells 100 _n , 100 ₁ , 100 ₂ , 100 ₃ User equipment 102 CP removing unit 104 Fast Fourier transform (FFT) unit 106 L1 / L2 control channel receiving unit 108, 116, 120, 128 Switching unit 110, 122 Separating unit ( DEMUX)
112 ₁ , 112 ₂ , 124 ₁ , 124 ₂ , 124 ₃ , 124 ₄ Channel estimation unit 114 Demodulation unit 126 Signal separation / demodulation unit 200 Base station apparatus 202, 202 ₁ , 202 ₂ , 202 ₃ , 202 ₄ multiplexing unit (MUX) )
204, 204 ₁ , 204 ₂ , 204 ₃ , 204 ₄ Fast inverse Fourier transform unit (IFFT)
206, 206 ₁ , 206 ₂ , 206 ₃ , 206 ₄ Guard interval insertion part (CP)
208 Scheduler 300 Access Gateway Device 400 Core Network 1000 Wireless Communication System

Claims (7)

A user apparatus that communicates with a base station apparatus equipped with a plurality of antennas,
One subframe is composed of a plurality of slots, and one slot is composed of a plurality of basic time units.
L1 / L2 control that is a first reference signal used for demodulation of an L1 / L2 control channel and a data channel transmitted from a predetermined antenna and is mapped within a predetermined basic time unit from the head of each subframe A first receiver for receiving a channel and a first reference signal;
A second reference signal used for demodulation of a data channel transmitted from an antenna other than the predetermined antenna, and a basic time after a basic time unit to which the L1 / L2 control channel and the first reference signal are mapped A second receiver for receiving a second reference signal mapped to the unit;
A user apparatus comprising:   The first receiving unit is an L1 / L2 control channel and a first reference signal transmitted from two antennas, and is mapped within three basic time units from the head of each subframe. The user apparatus according to claim 1, wherein the user apparatus receives the first reference signal.   3. The user apparatus according to claim 1, wherein the second reception unit receives a second reference signal mapped to a basic time unit near the center of each slot. One resource element is composed of one subcarrier and one basic time unit,
The first receiving unit is an L1 / L2 control channel and a first reference signal transmitted from two antennas, and is determined in advance among resource elements within three basic time units from the head of each subframe. Receiving the L1 / L2 control channel and the first reference signal mapped to the predetermined resource element,
The second receiving unit is mapped to a predetermined resource element determined in advance among resource elements included in a basic time unit after the basic time unit to which the L1 / L2 control channel and the first reference signal are mapped. The user apparatus according to claim 1, wherein the user apparatus receives a second reference signal. The first receiving unit receives an L1 / L2 control channel and a first reference signal mapped to different resource elements at a predetermined period,
The user apparatus according to claim 4, wherein the second receiving unit receives a second reference signal mapped to different resource elements at a predetermined period.   The user apparatus according to claim 5, wherein the predetermined period is a subframe. The second receiving unit maps the L1 / L2 control channel and the first reference signal for each resource block configured by a plurality of subcarriers and a plurality of basic time units according to the number of antennas provided in the user apparatus. The user apparatus according to claim 1, wherein the second reference signal mapped to a basic time unit after the basic time unit is received.

Images