MXPA06009602A - Mobile station device and transmission antenna selection method in the mobile station device - Google Patents

Abstract

There is provided a mobile station device capable of increasing the communication system capacity when performing a high-speed packet transmission of an uplink line. The mobile station has a plurality of antennas:antenna 1 and antenna 2. Among the signals received from a base station 2 of the adjacent cell, the mobile station compares a reception power of signal r21 received by the antenna 1 to a reception power of signal r22 received by the antenna 2. When“the reception power r21=the reception of r22”, the antenna 2 is selected as a transmission antenna. The uplink line signal is transmitted from the selected antenna to the base station 1, thereby reducing interference given to the base station 2 of the adjacent cell.

Description

MOBILE STATION DEVICE AND METHOD OF SELECTION OF TRANSMISSION ANTENNA IN THE MOBILE STATION DEVICE Field of the Invention The present invention relates to a mobile station apparatus and to a method of selecting transmission antenna in the mobile station apparatus. Background of the Invention In a TDD scheme in a mobile communication system, frames are separated in uplink frames (transmission frames in a mobile station, reception frames in a base station) and downlink frames (reception frames) in the mobile station, transmission frames in the base station). Additionally, in the TDD scheme, an uplink signal and a downlink signal are communicated to the same frequency band, and therefore the propagation path of the uplink signal and the link signal is the same falling. Using this property of the TDD scheme, there is a technique that performs the diversity of antenna selection transmission in which a downlink signal is transmitted from an antenna with higher reception power and an uplink signal (i.e. with a better state of the propagation path) in a base station having two antennas (see, for example, Patent Document 1). REF: 174950 If a plurality of antennas are provided with the mobile station, it is also possible to realize this antenna selection transmission diversity in the mobile station as in the base station. As a next-generation communication scheme, several techniques have been studied to implement the transmission of higher-speed packets in the cellular environment. Currently, the transmission of high-speed downlink paging has been studied mainly actively, but to improve the transmission efficiency in the complete communication system, it is essential to increase not only the transmission of high-speed pages in the downlink , but also a higher capacity and high speed in the uplink. In this uplink high-speed pay transmission, a high-speed payoff transmitted from a mobile station that moves near a cell boundary becomes a cause of interference that occurs in an adjacent cell. In particular, when the transmission power control is performed in the uplink, the transmission power of a high-speed packet transmitted from a mobile station becomes high, and causes extremely high interference in the adjacent cell, decreasing from this mode the capacity of the complete communication system. Accordingly, in order to implement the transmission of high-speed uplink paging in a cellular system, it is necessary to reduce the interference in an adjacent cell caused by a mobile station near a cell boundary. Patent Document 1: Patent Application Japanese Revealed No. 2000-353994. BRIEF DESCRIPTION OF THE INVENTION Problems to be solved by the invention However, when conventional diversity of antenna selection transmission is applied to a mobile station without change, transmission antennas are selected based on the states of the propagation routes between a plurality of antennas of the mobile station and a base station (i.e., the base station communicating with the mobile station) of a cell where the mobile station is located. Therefore, when a state in the propagation path between a selected antenna and a base station of an adjacent cell is also good, the interference caused in the adjacent cell becomes high. Under these circumstances, an increase in the system's capacity to implement high-speed uplink paging can not be expected. It is an object of the present invention to provide a mobile station apparatus and transmission antenna selection method in the mobile station apparatus to enable increases in communication system capacity when performing high-speed uplink packets and the like. Means for solving the problem A mobile station apparatus of the invention adopts a configuration provided with a plurality of antennas that receive both a signal transmitted from a first base station and another signal transmitted from a second base station of an adjacent cell that is adjacent to a cell of the first "base station", a selection section that selects an antenna that causes the least interference in the adjacent cell among the plurality of. antennas that the mobile station has, and a transmission section that transmits a signal to the first base station from the selected antenna. Advantageous effect of the invention According to the invention, in the case of performing high-speed uplink packets and the like, it is possible to reduce the interference caused in an adjacent cell and increase the capacity of the communication system. Brief Description of the Figures Figure 1 is a configuration diagram of a mobile communication system according to the modality 1 of the present invention; Figure 2 is a block diagram illustrating a configuration of a mobile station according to the mode 1 of the present invention; Figure 3 is a blog diagram illustrating a configuration of a mobile station according to mode 2 of the present invention; Figure 4 is a simulation result of interference power versus cumulative distribution function according to mode 2 of the present invention; Figure 5 is a configuration diagram of a mobile communication system according to the mode 3 of the present invention; Figure 6 is a block diagram illustrating a configuration of a mobile station according to mode 3 of the present invention; Figure 7 is a blog diagram illustrating a configuration of a mobile station according to the mode 4 of the present invention; Figure 8 is a blog diagram illustrating a configuration of a mobile station according to the mode 5 of the present invention; Figure 9 is a table showing a correspondence between an MCS level and the reception power according to the mode 5 of the present invention; Figure 10 is a flow diagram illustrating the operation of the mobile station according to the mode 5 of the present invention; Figure 11 is a block diagram illustrating a configuration of a mobile station according to the mode 6 of the present invention; and Figure 12 is a block diagram illustrating another configuration of the mobile station according to the mode 6 of the present invention. Detailed Description of the Invention Specifically described below, with reference to the appended figures, the embodiments of the present invention. Modality 1 Figure 1 is a configuration diagram of a mobile communication system according to mode 1 of the present invention. The mobile communication system includes a mobile station, and base station 1 and base station 2, and communications between the mobile station and each base station are performed in a TDD scheme. The mobile station 1 has two antennas, and each of the base station 1 and the base station 2 has an individual antenna. It is assumed that the mobile station receives a downlink signal with both the antenna 1 and the antenna 2, and transmits an uplink signal from one of the antenna 1 and the antenna 2. Additionally, the mobile station is currently held in a cell of the base station 1, and the base station 1 communicates commonly with the mobile station and a destination of transmission of the uplink signal of the mobile station. Additionally, the base station 2 is a base station of a cell adjacent to the cell of the base station 1. In this embodiment, the mobile station selects an antenna that causes less interference in the cell (adjacent cell) of the base station 2 of the antenna 1 and the antenna 2 as a transmission antenna, and transmits an uplink signal to the base station 1 from the selected antenna. Here, the uplink signal transmitted to the base station 1 is, for example, high-speed packet data. furthermore, in Figure 1, rn denotes a downlink signal that is transmitted from the base station 1 and is received at the antenna 1 of the mobile station, r? 2 denotes a downlink signal that is transmitted from the base station 1 and is received at antenna 2 of the mobile station, r21 denotes a downlink signal that is transmitted from base station 2 and is received at antenna 1 of the mobile station, and r22 denotes a downlink signal that is transmits from the base station 2 and is received at the antenna 2 of the mobile station. Although a plurality of adjacent cells exist around the cell of the base station 1, the adjacent cell is a cell that provides the highest reception power except the cell of the base station 1, and it is detected by a cell search. Figure 2 is a blog diagram illustrating a configuration of a mobile station according to mode 1 of the present invention. Each antenna 1 and antenna 2 receives both a downlink signal transmitted from the base station 1 and another downlink signal transmitted from the base station 2. The transmit / receive switch section 101, the radio reception processing section 102 , the adjacent cell pilot signal extraction section 103, the reception power measurement section 104, the pilot signal extraction section 105, the channel estimation section 106, and the demodulation section 107 are provided in association with the antenna 1. In the meantime, the transmit / receive switch section 201, radio reception processing 202, the adjacent cell pilot signal extraction section 203, the reception power measurement section 204, the section 205 for extracting the pilot signal, the channel estimation section 206 and the demodulation section 207 are provided in association with the an 2. The transmission / reception switching section 101 switches the transmission and reception of the antenna 1, and introduces a downlink signal received at the antenna 1 to the reception processing section 102 in a reception frame, and transmits an uplink signal inputted from the radio transmission processing section 403 to the base station 1 from the antenna 1 in a transmission frame. The radio reception processing section 102 performs the predetermined processing radius such as downconversion and the like of the received signals ru and r21 and input to the adjacent cell pilot signal extraction section 103, the signal extraction section 105 pilot and section 107 of demodulation. The section 103 of extraction of pilot signal from adjacent cell extracts a pilot signal P21 contained in the received signal r2? (ie, a pilot signal that is transmitted from the base station 2 of the adjacent cell and is received at the antenna 1 of the mobile station), and inputs the extracted pilot signal p2? to section 104 of reception power measurement. Is this extraction done in a CDMA scheme by discarding r2? with an extension code assigned to the pilot signal p2 ?, while it is performed in an OFDM scheme when extracting a sub-carrier assigned to the pilot signal p ?. The reception power measurement section 104 measures the reception power | p2? | of the pilot signal p2 ?, and introduces the result of the measurement to the transmission antenna selection section 404. The pilot signal extraction section 105 extracts a pilot signal n contained in the received signal rxl (ie a pilot signal that is transmitted from the base station and is received at the antenna 1 of the mobile station), and introduces the pilot signal pn extracted to section 106 of channel estimation. Using the pu pilot signal, the channel estimation section 106 obtains a channel estimation value between the antenna 1 and the base station 1 and introduces it to the demodulation section 107. The demodulation section 107 demodulates the received signal ru insofar as it performs compensation for phase rotation and the like based on the entered channel estimation value. In the demodulation section 107, in the CDMA scheme, the received signal ru is ignored, and then, it is demodulated in QPSK or the like, and the reception symbols are generated. In the OFDM block, the received signal ru is transformed to a frequency domain signal by FFT, and then, the reception symbols are generated for each sub-carrier. The generated reception symbols are entered into the combination section 301. Meanwhile, the transmission / reception switching section 201 switches the transmission and reception of the antenna 2, and introduces a downlink signal received in the antenna 2 to the receiving radio processing section 202 in a reception frame, and transmits an uplink signal inputted from the radio transmission processing section 403 to the base station 1 of the antenna 2 in a transmission frame. The radio reception processing section 202 performs the predetermined radio processing such as downward and similar conversion on the received signals ri2 and r22 and inputs them to the adjacent cell pilot signal extraction section 203, the extraction section 205 of pilot signal and demodulation section 207. The adjacent cell pilot signal extraction section 203 extracts a pilot signal p22 contained in the received signal r22 (ie, a pilot signal that is transmitted from the base station of the adjacent cell and antenna 2 of the station is received mobile) and introduces the extracted pilot signal p22 to the reception power measurement section 204. This extraction is performed in the CDMA scheme to the unzip r22 with an extension code assigned to the pilot signal p22, while it is performed in the OFDM scheme when extracting a sub-carrier assigned to the pilot signal p22 • L section 204 of reception power measurement measures the reception power | p22 | of the pilot signal p22, and introduces the measurement result to the transmission antenna selection section 404. The extraction section 205 of the pilot signal extracts a pilot signal p? 2 contained in the received signal r? 2 (ie a pilot signal that is transmitted from the base station and is received in the antenna 2 of the mobile station), and introduces the extracted pilot signal pi2 to channel estimation section 206. Using the pilot signal p? 2, the channel estimation section 206 obtains a channel estimation value between the antenna 2 and the base station 1, and introduces it to the demodulation section 207. The demodulation section 207 demodulates the received signal r12 insofar as it performs the compensation for phase rotation and the like based on the entered channel estimation value. In the demodulation section 207, in the CDMA scheme, the received signal ri2 is ignored, and then it is demodulated in QPSK or the like, and the reception symbols are generated. In the OFDM mode, the received signal r? 2 is transformed to a frequency domain signal by FFT, and then, for each sub-carrier, the reception symbols are generated. The generated reception symbols are entered into the combination section 301. In the combination section 301, the received reception symbols of the demodulation section 107 and the received reception symbols of the demodulation section 207 are combined, and the combined symbols are decoded in the decoding section 302. In this way reception data is obtained. In the meantime, the transmission data is encoded in the coding section 401, modulated in the modulation section 402, subjected to predetermined processing radius such as upconversion and the like, and then, entered into the selection section 404. transmit antenna "as an uplink signal The transmit antenna selection section 404 selects an antenna 1 and antenna 2 as a transmit antenna to transmit the uplink signal to the base station 1. When | p2? | <; | P22 |, the transmit antenna selection section 404 selects the antenna 1 as the transmitting antenna, and inputs the uplink signal inputted from the radio transmission processing section 403 to the transmission switching section 101. reception. Therefore, when | p2? | < | p22 |, the uplink signal submitted to the processing radio in the radio processing section "Transmission 403 is transmitted to the base station 1 from the antenna 1. On the contrary, when | P2I | = | P22 | A section 404 of transmission antenna selection selects antenna 2 as the transmission antenna, and inputs the uplink signal inputted from radio transmission processing section 403 to transmission / reception switching section 201. Accordingly, when / the uplink signal subjected to the processing radius in the radio transmission processing section 403 is transmitted to the base station 1 from the antenna 2. Thus, in this section, an antenna with lower transmit power of a transmitted pilot signal from the base station 2 is selected as an antenna for transmitting an uplink signal to the base station 1. In other words, in this mode, that communications are made in the TDD scheme, the transmit antenna selection section 404 selects an antenna as a worst state of the propagation path to the base station 2. of the adjacent cell as a transmit antenna of a signal of uplink. Accordingly, the uplink signal transmitted from the selected antenna such as the above is not easier to reach the base station 2 of the adjacent cell, i.e., causes less interference in the adjacent cell. Thus, in this embodiment, the transmit antenna selection section 404 selects an antenna that causes the least interference in the adjacent cell from the antenna 1 and the antenna 2, as a transmit antenna of an uplink signal. In addition, for convenience in the description, the number of antennas that the mobile station has is two in this mode, but three or more can also be used. In this case, the transmission antenna selection section 404 selects an antenna csn the lowest reception power of a pilot signal transmitted from the base station 2 from among a plurality of antennas that the mobile station has, such as a transmit antenna. an uplink signal to the base station 1. In other words, the transmit antenna selection section 404 selects an antenna that causes the least interference in the adjacent cell among a plurality of antennas, such as a signal transmitting antenna uplink. In this way, in this mode, an uplink signal is transmitted from an antenna with the worst state of the propagation path to the base station of the adjacent cell from among a plurality of antennas that the mobile station has, in this way the interference caused by the adjacent cell can be reduced, and as a result, it is possible to increase the capacity of the communication system. Modality 2 This mode describes the case that a mobile station performs transmission power control in an uplink signal. In the aforementioned embodiment 1, an antenna with the lowest reception power of a pilot signal transmitted from the base station 2 of the adjacent cell is selected as a transmission antenna of an uplink signal. In this selection, it is possible to securely select an antenna that causes the least interference from the adjacent cell as a transmission antenna. However, since a state of the propagation path to the base station 1 is not taken into consideration in the selection of the antenna, it is considered that the uplink signal does not meet the required reception quality in the base station 1 depending on the state the propagation route. Thus, in this embodiment, transmission power control is performed on an uplink signal to meet the required reception quality of the uplink signal in the base station 1, while selecting a transmission antenna with a state of the propagation path between each antenna and base station 1 taken into consideration. Figure 3 is a blog diagram illustrating a configuration of a mobile station according to mode 2 of the present invention. In addition, the same sections as modality 1 (Figure 2) are assigned to the same reference numbers and descriptions of them will be omitted. In Figure 3, the reception power measurement section 108 and the power ratio calculation section 109 is provided in association with the antenna 1. A pilot signal pn extracted in the pilot signal extraction section 105 is introduced to the reception power measurement section 108. The reception power measurement section 108 measures the reception power | pn | of the pilot signal pii, and introduces the measurement result to the power ratio calculation section 109 and the transmission power control section 405. Additionally, the reception power | p2i | measured in section 104 of reception power measurement is entered into section 109 of power ratio calculation. Then, the power ratio calculation section 109 calculates a relation of the reception power | p2? to the reception power | pu | (| P22 | / | Pii |) / enter the result of the calculation to the transmission antenna selection section 404. Meanwhile, the reception power measurement section 208 and the power ratio calculation section 209 are provided in association with the antenna 2. A pilot signal p? 2 extracted in the pilot signal extraction section 205 is input to the reception power measurement section 208. The reception power measurement section 208 measures the reception power | p? 2 | of the pilot signal p? , and introduces the measurement result to the power ratio calculation section 209 and the transmission power control section 405. Additionally, the reception power | p22 | Measured in the reception power measurement section 204 is entered into the power ratio calculation section 209. Then, the power ratio calculation section 209 calculates a relation of the reception power | p22 | to the reception power | p? 2 | (IP22 | / | pi2 |) and enter the result of the calculation to the transmission antenna selection section 404. The transmission antenna selection section 404 selects an antenna 1 and antenna 2 as a transmission antenna to transmit an uplink signal to the base station 1. When | p211 / | pu | <; | p22 | / | P12 | / the transmission antenna selection section 404 selects the antenna 1 as the transmission antenna, and introduces an uplink signal introduced in the radio transmission processing section 403 to the transmission / reception switching section 101. Therefore, when IP211 / IP111 < IP22 I / IP12 I, the uplink signal subjected to the processing radius in the radio transmission processing section 403 is transmitted to the base station 1 from the antenna 1. On the contrary, when | p2i | / | Pu | = | p22 | / | P12 | the transmission antenna selection section 404 selects the antenna 2 as the transmission antenna, and introduces the uplink signal introduced in the radio transmission processing section 403 to the transmission / reception switching section 201. Accordingly, when IP211 / 1P111 = IP22 I / IP12 I, the uplink signal subjected to the processing radius in the radio transmission processing section 403 is transmitted to the base station 1 from the antenna 2. In other words, in this selection, an antenna with a more sticky relationship, is selected as a transmit antenna of an uplink signal to the base station 1, where the ratio is of the reception power of a pilot signal transmitted from the base station to the power of receiving a pilot signal transmitted from the base station 1. The selection result is input to the transmission power control section 405. In addition, the reason for this selection will be described later. Additionally, when the transmit antenna selection section 404 selects the antenna 1, the transmission power control section 405 determines the transmission power Pti of an uplink signal according to the following equation (1), to fulfill with the required quality of reception of the uplink signal in the base station 1 Pti = aii x targetSIR x IBTs ... (1) Here, the amount of attenuation in the propagation path between antenna 1 and the station base 1, IBTs is the amount of interference to which the base station 1 is subjected, and targetSIR is target SIR in the base station 1. In addition, IBts and targetSIR are reported in the base station 1 in the 'mobile station with the information of control . Additionally, since a transmit power value of the pu pilot signal is also reported in the base station, from the base station 1 to the mobile station as the control information, the transmission power control section 405 can obtain or N by dividing the reported value of the transmission power by the reception power Ipul.

Meanwhile, when the transmit antenna selection section 404 selects the antenna 2, the transmit power control section 405 determines the transmit power Pt2 of the uplink signal according to the following equation (2),. to fulfill the required quality of reception of the uplink signal in the base station 1. Pt2 =? 2 x SIR target x IBts ... (2) Agui, ai2 is the amount of attenuation in the propagation path between the antenna 2- and the base station 1. Since a transmission power value of the pilot signal P12 in the base station is also reported from the base station 1, to the mobile station as control information, the power control section 405 of transmission can obtain a2 by dividing the reported value of the transmit power by the reception power | p? 2 | - The transmission power control section 405 controls the transmission power of the uplink signal subjected to the processing radius in the radio transmission processing section 403 to be the transmission power value obtained in equation (1) or (2) mentioned above. This transmission power control is generally referred to as open circuit transmission power control. Next, the reason why the transmit antenna selection section 404 performs the antenna selection as described above will be described. The transmission power Pti required when the uplink signal is transmitted from the antenna 1 of the mobile station is as in equation (1) above, while the transmitting power Pt2 is required when transmitting an uplink signal from antenna 2 of the mobile station is like in the equation (2) mentioned above. Additionally, the IY interference imposed on the base station 2 of the adjacent cell is as in the equation (3) when transmitting the uplink signal from antenna 1 to transmission power Pti of equation (1) mentioned above. To uí, 2? represents the amount of attenuation in the propagation path between antenna 1 and base station 2. Equation (3) mentioned above results in equation (4) from equation (1) mentioned above. Iti = (a ?? oí2i) x SIR target x IBts • • • (4) Meanwhile, the interference It2 imposed on the base station 2 of the adjacent cell is as in equation (5) when the uplink signal is transmitted from antenna 2 to the transmission power Pt2 of equation (2) mentioned above. Here, a22 represents the amount of attenuation in the propagation path between antenna 2 and base station 2. It2 = Pt2 / 22 • .. (5) Equation (5) mentioned above results in equation (6) ) of equation (2) mentioned above. It2 = (or £? 2 /? £ 22) x targetSIR x IBts ... (6) Here, in this mode, as in mode 1 described above, the transmitting antenna selection section 404 selects an antenna that causes the least interference "in the adjacent cell from the antenna 1 and the antenna 2, as an antenna for transmitting an uplink signal In other words, when It? <It2, the antenna 1 is selected as the antenna In contrast, when It? = It2, antenna 2 is selected as the transmission antenna. (cf ?? / a2?) < (a? 2 / a22), antenna 1 is selected as the transmission antenna. On the other hand, when (oin / a2?) = (012/022) antenna 2 is selected as the transmission antenna. Additionally, since the amount of attenuation to the propagation path is an inverse proportion to the reception power, when selecting 1 as the transmission antenna 1 when | p2? | / | Pn | < | P22 | / | P12 | as long as antenna 2 is selected as the transmission antenna when | p2i | / f Pii [= IP22 I / I P12 I, the transmit antenna selection station 404 selects an antenna that causes the lowest - interference in the adjacent cell from antenna 1 and antenna 2 as an antenna. transmission of an uplink signal. Thus, in this embodiment, when an uplink signal is transmitted to the base station 1 from the mobile station to the required transmission power Pti or Pt2 such that the signal is received in the target SIR in the base station 1, it is selects an antenna that causes the least interference at the base station 2 of the adjacent cell. Here, a computer simulation result is described to estimate the performance of this modality. Figure 4 shows a cumulative distribution function (CDF) of the interference power 'in the base station 2 of the adjacent cell. This average interference power on the horizontal axis is normalized by the maximum value. It is understood from the simulation result that in the selection method • of a transmission antenna according to this mode, the interference power can be reduced by ldB compared to the conventional selection method (where antenna 1 is selected when | pp | - IP12I / while antenna 2 is selected when | Pn | < | P12 |) • Also, for convenience in the description, the number of antennas that the mobile station has is two in this mode, but You can also use three or more antennas. In this case, as an antenna transmitting an uplink signal to the base station 1, the transmit antenna selection section 404 selects an antenna with the smallest ratio of the transmission power of a pilot signal transmitted from the base station 2 to the reception power of a "pilot signal transmitted from the base station 1, from a plurality of antennas that the mobile station has In other words, the transmit antenna selection section 404 selects an antenna that causes the lower interference in the adjacent cell between a plurality of antennas, such as an antenna for transmitting an uplink signal, In this way, in this mode, when transmission power control is performed on an uplink signal, that an antenna for transmitting the uplink signal is selected based on the power ratio of reception of the pilot signals as described above, the interference caused in the adjacent cell can be reduced, while meeting the required reception quality in the base station receiving the uplink signal. As a result, it is also possible to increase the capacity of the communication system even when the transmission power control is performed on the uplink signal. Modality 3 This mode describes the case where the base station 1 and the base station 2 have a plurality of antennas. Figure 5 is a configuration diagram of a mobile communication system according to the mode 3 of the present invention. This mobile communication system differs from that in mode 1 in the following aspects. That is, each of the base station 1 and the base station 2 has two antennas, and transmits a downlink signal from both the antenna 1 and the antenna 2 to a mobile station. In Figure 5, ri; jk denotes a downlink signal that is transmitted from an antenna j of a base station i and is received in an antenna k of a mobile station. Therefore, r? 2? denotes a downlink signal that is transmitted from the antenna 2 of the base station 1 and is received at the antenna 1 of the mobile station. In the case where a base station has a plurality of antennas in this way, it is necessary to consider that the base station performs a combination of maximum relationship in the uplink signals of the antennas. In other words, the reception power | p2? | and j P121 in mode 1 are replaced respectively with V (| 2i? | 2+ IP221] 2) and V (| P2X2 J 2+ IP22212) • Here, Pijk is a pilot signal contained in a received signal rijk, and | Pij | is the reception power of the pilot signal pij - Figure 6 is a block diagram illustrating a configuration of a mobile station according to the mode 3 of the present invention. In addition, the same configurations as mode 1 (Figure 2) are assigned to the same reference numbers, and descriptions of them will be omitted. In Figure 6, N configurations 10 are provided each with a combination of adjacent cell pilot signal extraction section 103, reception power measurement section 104, pilot signal extraction section 105, channel estimation section 106 and demodulation section 107, where N is the same number as the number of antennas that the base station has. Similarly, N configurations 20 are provided each with a combination of adjacent cell pilot signal extraction section 203, reception power measurement section 204, pilot signal extraction section 205, channel estimation section 206, and demodulation section 207, where N is the same number as the number of antennas that the base station has. Here, as shown in Figure 5, since each of the base station 1 and base station 2 has two antennas, N of the mobile station is two. The adjacent cell pilot signal extraction section 103 of N = l extracts a pilot signal p2u contained in a received signal r2u (i.e., a pilot signal that is transmitted from the antenna 1 of the base station 2 of the adjacent cell and it is received on antenna 1 of the mobile station), and enters the pilot signal p2 ?? extracted to the reception power measurement section 104 of N = l. The reception power measurement section 104 of N = l measures the reception power | p2i? | or the pilot signal P211, and input the measurement result to the combination section 110. Additionally, the adjacent cell pilot signal extraction section 103 of? = 2 extracts a pilot signal p22? contained in a received signal r22i (i.e., a pilot signal that is transmitted from the antenna 2 of the base station 2 and the adjacent cell is received in the antenna 1 of the mobile station), and introduces the pilot signal P221 extracted to the section 104 of power measurement of the section of? = 2. The reception power measurement section 104 of N = 2 measures the reception power | p22i | of the pilot signal P221, and introduces the measurement result to the combination section 110. The combining section 110 obtains the combined reception power (IP2111 ++ IP22112) in the antenna 1 of the mobile station and introduces it to the transmission antenna selection section 404. Meanwhile, the adjacent cell pilot signal extraction section 203 of N = l extracts a pilot signal p2 2 2 contained in a received signal r2i2 (i.e., a pilot signal that is transmitted from the antenna 1 of the base station 2) of the adjacent cell and is received at antenna 2 of the mobile station) and introduces the extracted pilot signal p2i2 to the receiving power measurement section 204 of N = 1. The reception power measurement section 204 of N = l measures the reception power | P2121 of the pilot signal P212, and enter the measurement result to the combination section 210. Additionally, the adjacent cell pilot signal extraction section 203 of N = 2 extracts a pilot signal p222 contained in a received signal r22 (i.e., a pilot signal that is transmitted from the antenna 2 of the base station 2 of the cell adjacent and received at antenna 2 of the mobile station), and introduces the extracted pilot signal P222 to the receiving power measurement section 204 of N = 2. The reception power measurement section 204 of N = 2 measures the reception power | P22 1 of the pilot signal P222, and introduces the measurement result to the combination section 210. The combining section 210 obtains the combined reception power (| P212 | 2+ [P222 | 2) in the antenna 2 of the mobile station and enters it into the transmission antenna selection section 404. The transmission antenna selection section 404 selects one of the antenna 1 and antenna 2 as a transmit antenna to transmit an uplink signal to the base station 1. When (| P21112 + | P22112) <; (| p2? 212+ | P222 | 2), the transmission antenna selection section 404 selects the antenna 1 as the transmission antenna, and inputs the uplink signal introduced in the radio transmission processing section 403 to the transmission switching section 101 of reception. Therefore, when (| p2n 12+ | p22i | 2) < V (| p2i212 + IP222 | 2), the uplink signal subjected to the processing radius in the radio transmission processing section 403 is transmitted in the base station 1 from the antenna 1. On the contrary, when (] P21112 + IP22112) = ^ / (IP212 I 2+ 1 P22212) / the transmission antenna selection section 404 selects the antenna 2 as the transmission antenna, and inputs the uplink signal inputted from the radio transmission processing section 403 to the section 201 of transmission / reception switching. Accordingly, when (P21112 + IP22112) = (I 21212+ IP222 I 2), the uplink signal subjected to the processing radius in the radio transmission processing unit 403 is transmitted to the base station 1 from the antenna 2. this way, in this selection, an antenna with lower combined reception power of the pilot signals transmitted from a plurality of antennas of the base station 2 is selected as a transmit antenna of an uplink signal to the base station 1. As in the aforementioned embodiment 1, the uplink signal transmitted from the antenna selected in this way causes less interference in the adjacent cell. Thus, in this embodiment, the transmission antenna selection section 404 selects an antenna that causes less interference in the adjacent cell of the antenna 1 and antenna 2, as a transmit antenna of an uplink signal. In addition, to simplify the calculation in the mobile station, the calculation can be performed as V approaches (| p2i? | 2+ | p22i | 2) in | P211 1 + | P221 1 and V ([P212 I 2+ I P222 I 2) in Additionally, for convenience in the description, the number of antennas that the mobile station has is two in this mode, but also three or more antennas can be used. In this case, as in the above, the transmission antenna selection section 404 selects an antenna with the lowest combined reception selection of the pilot signals transmitted from a plurality of antennas of the base station 2 from among a plurality of antennas The mobile station has, as an antenna for transmitting an uplink signal to the base station 1. In other words, the transmission antenna selection section 404 selects an antenna that causes the least interference in the adjacent cell between a plurality of antennas, such as a transmission antenna of an uplink signal.

In this way, in this embodiment, since a transmitting antenna is selected based on the combined reception power in each antenna of the mobile station, even when the base station has a plurality of antennas and performs a maximum radio combination in the uplink signals of the antennas, it is possible to reduce the interference caused in the adjacent cell, and as a result, the capacity of the communication system can be increased. Modality 4 This embodiment describes the case where the base station 1 and the base station 2 have a plurality of antennas such as mode 3, and the transmission power control is performed on uplink signals such as mode 2. A configuration of a mobile communication system according to this embodiment is the same as in Figure 5. Therefore, it also needs to be considered that the base station performs the maximum radio combination, and the uplink signals of the antennas. In other words, the reception power (p2? |, | P221 | P ?? | and IP12"J in mode 2 is replaced respectively with V (| p2u | 2+ | p22i | 2), V (| p2? 2 | 2+ IP222I2), (| pm | 2+ | p? 2? | 2) and (| pu2 | 2 + I P122 I 2). Figure 7 is a blog diagram illustrating a configuration of a mobile station according to the embodiment 4 of the invention. In addition, the same configurations as in modality 2 (Figure 3) or modality 3 (Figure 6) are assigned the same reference numbers, and descriptions of the ismas will be omitted. In Figure 7, N configurations 30 are provided each with a combination of adjacent cell pilot signal extraction section 103, reception power measurement section 104, pilot signal extraction section 105, channel estimation section 106 and demodulation section 107, where N is the same number as the number of antennas that the base station has. Similarly, N configurations 40 are provided each with a combination of adjacent cell pilot signal extraction section 203, receiving power measurement section 204, pilot signal extraction section 205, channel estimation section 206, and demodulation section 207, where N is the same number as the number of antennas that the base station has. Here, as shown in Figure 5, since each of the base station 1 and base station 2 has two antennas, N of the mobile station is two. The pilot signal extraction section 105 of N = 1 extracts a plu pilot signal contained in a received signal riu (ie, a pilot signal that is transmitted from the antenna 1 of the base station 1 and is received in the antenna 1 of the mobile station), and introduces the pilot signal extracted pul to the reception power measurement section 108 of N = l. The reception power measurement section 108 of N = l measures the reception power | pm | of the pilot signal plu, and introduces the measurement result to the combination section 111 and the transmission power control section 405. Additionally, the pilot signal extraction section 105 of N = 2 extracts a pilot signal P121 contained in a received signal ri2? (ie a pilot signal that is transmitted from the antenna 2 of the base station 1 and is received in the antenna 1 of the mobile station), and introduces the extracted pilot signal p12? to section 108 of reception power measurement of? = 2. The reception power measurement section 108 of? = 2 measures the reception power | pi2i | of the pilot signal P121, and introduces the measurement result to the combination section 111 and the transmission power control section 405. The combining section 111 obtains the combined reception power (| pm | 2+ | pi2i | 2) in the antenna 1 of the mobile station, and introduces it to the section 109 for calculating the transmission ratio. Additionally (| 211 i 2+ | p22i | 2) obtained in the combination section 110 is also entered into the power ratio calculation section 109. The power ratio calculation section 109 calculates a relation (V (| p2u | 2+ | p22i | 2) / (| Pm | 2+ | pi2i | 2)) d the combined reception power (| P21112 + | P221! 2) to the combined reception power V (| pm | 2+ | pi2i | 2) / and input the measurement result to the transmission antenna selection section 404. Meanwhile, the pilot signal extraction section 205 of N = l extracts a pilot signal pu2 contained in a received signal ru2 (ie, a pilot signal which is transmitted from the antenna 1 of the base station 1 and is received in the antenna 2 of the mobile station), and introduces the extracted pilot signal pu2 to the reception power measurement section 208 of N = l. The reception power measurement section 208 of N = l measures the reception power IP112I of the pilot signal pu2, and introduces the measurement result to the combination section 211 and the transmission power control section 405. Additionally, the pilot signal extraction section N = 2 extracts a pilot signal pi22 contained in a received signal ri22 (i.e. a pilot signal that is transmitted from the antenna 2 of the base station 1 and is received in the antenna 2 of the mobile station), and introduces the extracted pilot signal P122 to the receiving power measurement section 208 of N = 2. The reception power measurement section 208 of? = 2 measures the reception power P1221 shows the pilot signal P122 and introduces the measurement result to the combination section 211 and the transmit power control section 405. The combining section 211 obtains the combined reception power (| P11212 + [122 j 2) in the antenna 2 of the mobile station, and introduces it to the transmission ratio calculation section 209. Additionally, ([P21212 + 1 P222 | 2) obtained in the combination section 210 is also entered into the power ratio calculation section 209. Section 209 of power ratio calculations calculates a V (IP212 I2 + IP222 I 2) / V (| p2 2 | 2+ | pi22 | 2)) ratio of the combined reception power (| P212 | 2 + 1 222 | 2) at the combined reception power (I P112 I 2+ I P122 I 2) - introduces the measurement result to the transmission antenna selection section 404. The transmission antenna selection section 404 selects one from the antenna 1 and the antenna 2 as a transmission antenna for transmitting an uplink signal to the base station 1. When (| p21l | 2+ | P22l | 2) / ? Í (| p ??? | 2+ | pi2l | 2) < (| p212 | 2+ | p222) / (| p? l2 | 2+ | pi22 |), the transmission antenna selection section 404 selects antenna 1 as the transmission antenna, and introduces the uplink signal introduced of the radio transmission processing section 403 to the transmission / reception switching section 101. Therefore, when V (| p2 ?? | 2+ | p22? | 2 / (| Pm | 2+ IP12112) < V (| p2? 2 | 2 + I P22212) / (I P112 I 2+ I P122 I 2) The uplink signal subjected to the processing radius in the radio transmission processing section 403 is transmitted to the base station 1 from the antenna 1. On the contrary, when (| P2i? 12+ IP2211 / (I Pin 12+ IP2211) = (IP21212 + 1 P22212) / V (| pn212 + IP12212 ), the transmission antenna selection section 404 selects the antenna 2 as the transmission antenna, and inputs the uplink signal inputted from the radio transmission processing section 403 to the transmission transmission switching section 201. Therefore, when (I P21112 + 1 P22112) / (I pm 12+ 1 P12112) =? / (I p2i212 + 1 P22212) / (I P11212 + 1 P1221 2), the uplink signal subjected to the processing radius in section 403 The radio transmission processing is transmitted to the base station 1 from the antenna 2. The selection result is input to the transmission power selection section 405. When the transmit antenna selection section 404 is antenna selection 1, the transmission power control section 405 determines the transmission power Pti of the uplink signal according to the following equation (7), to comply with the required quality of reception of the uplink signal in the base station 1. Here, it is considered that the uplink signals of the two antennas are combined in the base station 1. Pti = l /. { . { l / a) + (l / i2i)} x targetSIR x IB S ... (7) Here, OIIIII is the amount of attenuation in the propagation path between antenna 1 of the mobile station and antenna 1 of base station 1, a? 2? is the amount of attenuation of the propagation path between the antenna 1 of the mobile station and the antenna 2 of the base station 1, IBTS is the amount of interference to which the base station 1 is subjected, and target SIR is target SIR in the base station 1. In addition, IBTS and targetSIR is notified from the base station 1 to the mobile station as control information. Additionally, the transmission power values of the pilot signals p and p? 2? at the base station, the mobile station 1 is also notified as the control information from the base station 1, and therefore, the transmit power control section 405 can obtain m and OI I 2 respectively when dividing the reported transmit power value by the reception power | p | or | p? 2i | . Meanwhile, when the transmit antenna selection section 404 selects an antenna 2, the transmission power control section 405 determines the transmission power Pt2 of the uplink signal according to the following equation (8), to comply with the required reception quality of the uplink signal in the base station 1. Here, it is considered that the uplink signals of the two antennas are combined in the base station 1. Pt2 = l /. { (l /? £ 2) + (1 / Q / i22)} x targetSIR x IBTS ... (8) Here, "U2 is the amount of attenuation in the propagation path between antenna 2 of the mobile station and antenna 1 of base station 1, and c? 22 is the amount of attenuation in the propagation path between the antenna 2 of the mobile station and the antenna 2 of the base station 1. Since the values of the transmit powers of the pilot signals pU2 and P122 are also reported in the base station, from the base station 1 to the mobile station as control information, the transmission power control section 405 can have o2u2 and i22 respectively by dividing the multiplied value of the transmission power by the transmission power | pu2 | o [P1221 - In addition, to simplify the calculation in the mobile station, the calculation can be made as long as it approaches V (| p2ll | 2+ | P22l | 2) a (| P21l | 2+ | P22l | 2), (j P212 | 2+ | P222 | 2) a IP2121 + I 22212, V (| pm | 2+ | p22i | 2) to (| Pin | + 1 P1211, y (I P11212 + 1 P12212) to I 1121 + 1 Px221 - Additionally, for convenience in the description, the number of antennas that the mobile station has in this mode, but also three or more antennas can be used In this case, as in the previous one, the transmitting antenna selection section 404 selects an antenna having the smallest power ratio of combined reception of the pilot signals from a plurality of antennas that the mobile station has, such as an antenna for transmitting an uplink signal to the base station 1. In other words, the transmission antenna selection section 404 it selects an antenna that causes the lowest interference in the adjacent cell from a plurality of antennas, such as an antenna for transmitting an uplink signal, in this way, when the transmission power control is performed In the uplink signals, a transmit antenna is selected based on the ratio of the combined reception power in each antenna of the mobile station. Therefore, even when the base station has a plurality of antennas and performs the combination of maximum ratio in the uplink signals of the antennas, the interference caused in the adjacent cell can be reduced, as long as the quality is met required reception at the base station receiving the uplink signal. As a result, it is also possible to increase the capacity of the communication system when controlling the transmission power in the uplink signal. Modality 5 This modality describes the case where a mobile station performs adaptive modulation and coding. Figure 8 is a blog diagram illustrating a configuration of a mobile station according to the mode 5 of the present invention. In addition, the same configurations as in mode 1 (Figure 2) or mode 2 (Figure 3) are assigned to the same reference numbers, and descriptions thereof will be omitted.

The reception power | pn | Measured in the reception power measurement section 108 is input to the MCS determination section 112. Additionally, the reception power | pi2¡ measured in the reception power measurement section 208 is input to the MCS determination section 212. Based on the reception power] pn |, the MCS determination section 112 determines a useful level of MCS (Modulation Coding Scheme) when an uplink signal is transmitted from the antenna 1. Additionally, based on the reception power] P121, the MCS determination section 212 determines a useful level of MCS when an uplink signal is transmitted from the antenna 2. The determination of the MCS level is made as follows. Figure 9 is a table showing a correspondence between the MCS level and the reception power. In the table, a plurality of modulation coding schemes indicated by a plurality of MCS levels are prepared in association with the reception power. Additionally, in this table, as the MCS level is increased, the modulation coding scheme has a higher transmission speed. With reference to the table, the MCS determination sections 112 and 212 determine the useful levels of MCS for each antenna. In general, the SNR level in the base station is used in the determination of MCS in the mobile station. In the TDD scheme, since the uplink signal and the downlink signal have the same propagation path, and have almost the same characteristics of the propagation path, in this mode, the determination is made using the power of reception | pouf and | P121 in the mobile station. In other words, this mode causes the reception level S? R in the base station to be in a proportional relationship with the reception power level in the mobile station. More specifically, the MCS determination section 112 determines the level = 1 of MCS (scheme of - modulation: QPSK, coding speed R = 1/3) as a usable level of MCS when the reception power | pu | is less than -100 dBm, level = 2 of MCS (modulation scheme), QPSK, coding rate R = 1/2) as a usable level of MCS when the reception power (pu | is -100 dBm or more) less than -96 dBm, level = 3 MCS (modulation scheme: 16 QAM, coding rate R = 1/2) as a usable level of MCS when the reception power | Pu | is -96 dBm or more and less than -90 dBm, and level = 4 MCS (modulation scheme: 16 QAM, coding speed R = 3/4) as a usable level of MCS when the reception power | pn | is -90 dBm or more and less than -84 dBm. The determination is also made in the MCS determination section 212 as the MCS determination section 112 based on the reception power | P121 • The respective determination results in the MCS determination sections 112 and 212 are both input to section 406 of MCS comparison. Comparison section 406 of MCS compares the level of MCS (level of MCS usable in antenna 1) determined in section 112 of determination of MCS with MCS level (level of MCS usable in antenna 2) determined in the section 212 of determination of MCS. In other words, MCS levels are compared between the antennas. Then, when the level of MCS usable in antenna 1 differs from the level of MCS usable in antenna 2, in order to 'obtain maximum performance, MCS comparison section 406 selects a higher level of MCS, insofar as it gives instructions to the transmission antenna selection section 404 to select an antenna with the highest level of MCS. For example, the MCS comparison section 406 inputs "1" to the transmit antenna selection section 404 instructs to select the antenna 1, while entering "2" to the transmission antenna selection section 404 to giving instructions for selecting the antenna 2. According to this instruction, the transmission antenna section 404 selects an antenna with a higher level of MCS from antenna 1 and antenna 2, as an antenna for transmitting the uplink signal . Additionally, the MCS comparison section 406 transfers the selected MCS level to the coding section 401 and the modulation section 402. The coding section 401 and the modulation section 402 perform the coding and modulation with a modulation scheme coding rate corresponding to the level of MCS transferred from the MCS comparison section 406, respectively. In the meantime, when the level of MCS usable in antenna 1 is the same as the MCS level usable in antenna 2, put, that the same performance is obtained when an uplink signal is transmitted from any of the antennas, the MCS comparison section 406 instructs the transmission antenna selection section 404 to select an antenna that causes the least interference from the adjacent cell as an antenna for transmitting the uplink signal. When the MCS levels are the same as each other, for example, the MCS comparison section 406 enters "0" into the transmission antenna selection section 404. According to this instruction, the transmission antenna selection section 404 selects the antenna that causes the least interference in the adjacent cell from the antenna 1 and the antenna 2, as an antenna for transmitting the uplink signal. A method for selecting a transmission antenna in this case is the same as in the aforementioned modality 1. The MCS comparison section 406 transfers the MCS level to the coding section 401 and the modulation section 402. The coding section 401 and the modulation section 402 perform the coding and modulation with a coding rate and modulation scheme corresponding to the level of MCS transferred from the MCS comparison section 406., respectively. The aforementioned operation is described below using a flow chart. Figure 10 is the flow diagram illustrating the operation of the mobile station according to the mode 5 of the present invention. In Figure 10, first, in the ST (step) 10, the reception power | pu | and | P121 • Then, ST20, a Lx level of MCS is determined according to the reception power | pn |, and an L2 level of MCS- is determined according to the reception power | p? 2 | - In ST30, the Li level of MCS is compared to the L2 level of MCS. When I ? L2 (ST30: NO), in ST40, an antenna with a higher level of MCS is selected as a transmission antenna. Meanwhile, when Li = L2 (ST30: YES), in ST50, measures the reception power | p2? Y I 2 1 / Y in ST60, compare the reception power | p2? | Y IP221 - Then, when | P211 < | P221 (ST60: YES), in ST70, antenna 1 is selected as a transmission antenna, whereas when IP211 = I 22 (ST60: NO), in ST80, antenna 2 is selected as a transmission antenna. Thus, in this embodiment, when the usable levels of MCS (modulation coding schemes) are different from a plurality of antennas, an antenna with the highest level of MCS is transmitted as a transmit antenna. Meanwhile, when the usable levels of MCS are the same among a plurality of antennas, an antenna that causes the lowest interference in the adjacent cell is selected as a transmit antenna. In this way it is possible to reduce the interference caused in the adjacent cell without decreasing the performance, and as a result, the capacity of the communication system can be increased. Modality 6 When a mobile station is located in the vicinity of the base station 1 (near the center of the cell of the - base station 1), originally the interference caused by the adjacent cell is low. On the contrary, when a mobile station is located near the cell boundary, the interference caused in the adjacent cell is high. Therefore, in this embodiment, an antenna with the best state of the propagation path with the base station 1 is selected as a transmit antenna when the mobile station is located in the vicinity of the base station 1, while a The antenna that causes the least interference in the adjacent cell is selected as a transmit antenna when the mobile station is located near the cell boundary. Figure 11 is a block diagram illustrating the configuration of a mobile station according to the mode 6 of the present invention. In addition, the same configurations as in mode 1 (Figure 2) or mode 2 (Figure 3) are assigned to the same reference numbers, and descriptions thereof will be omitted. The reception power | pu |. measured in the reception power measurement section 108 and the reception power | "Pi21 measured in the receiving power measurement section 208 are input to the average section 407 and the transmission antenna selection section 404. The average selection 407 obtains an average value of the reception power | pn | and the reception power | P121 / and also obtains an average value of a prolonged term from the average value In r words, the average section 407 obtains a long-term average of the reception power of the pilot signal The long-term average obtained is entered into the transmission antenna selection section 404. Since pu and pa2 are pilot signals transmitted bfrom the base station 1, it is possible to estimate a distance between the base station 1 and the mobile station from the receiving power, in r words, when the distance is longer, since the attenuation in the propagation route, reception becomes low. Therefore, the transmission antenna selection section 404 compares the long-term average of the reception power with a threshold. Then, when the long-term average of the reception power is less than or equal to a threshold (i.e., the distance between the base station 1 and the mobile station is less than a threshold), the antenna selection section 404 transmission determines that the mobile station is located near the center of the cell of the base station and causes less interference in the adjacent cell, and selects an antenna with a better state of the propagation path with the base expression 1 of antenna 1 and antenna 2, as a transmission antenna that an uplink. More specifically, the transmit antenna selection section 404 selects antenna 1 when | Pn | = | P121 while selecting antenna 2 when | p ?? | < | Pi2 | • Meanwhile, when the long-term average of the reception power is less than the threshold (i.e., the distance between the base station 1 and the mobile station is a threshold), the transmission antenna selection section 404 determines that the mobile station is located near the boundary of the cell and causes less interference in the adjacent cell, and selects an antenna that causes the least interference in the base station 2 of the adjacent cell from antenna 1 and antenna 2, as a transmission antenna of an uplink signal. The specific selection method is as described in mode 1. Here, the threshold used in the transmission antenna selection section 404 is notified from the base station 1 as part of the reception data, and is entered into the section 404 of transmission antenna selection. In determining the threshold, for example, the base station -1 considers the allowed amount of interference in the adjacent cell, the number of mobile stations retained in the adjacent cell and the like. More specifically, the base station increases the reception power threshold as the allowable amount of interference in the adjacent cell is smaller, and additionally, increases the transmission power threshold as the number of stations becomes larger. mobile phones retained in the adjacent cell. In addition, when the mobile station performs transmission power control on the uplink signals, the configuration is as described below. Figure 12 is a block diagram illustrating another configuration of the mobile station according to the embodiment 6 of the invention. In addition, the same sections as modality 1 (Figure 2) or modality 2 (Figure 3) are assigned to the same reference numbers, and descriptions thereof will be omitted. Additionally, the operation of the average section 407 in Figure 12 is the same as in Figure 11. When the long-term average of the reception power is more than or equal to a threshold (i.e., the distance between the station base 1 and the mobile station is smaller than a threshold), the transmission antenna selection section 404 in Figure 12 selects an antenna with a better condition of the propagation path with the base station 1 of the antenna 1 and the antenna 2, as a transmission antenna of an uplink. More specifically, the transmit antenna selection section 404 selects antenna 1 when | Pn | = | pi2 | / while selecting antenna 2 when | Pn I < I 12 | • Meanwhile, when the long-term average of the reception power is less than the threshold (i.e., the distance between the base station 1 and the mobile station is a threshold or more) the transmission antenna selection section 404 selects an antenna that causes the least interference in the base station 2 in the adjacent cell from the antenna 1 and the antenna 2, as a transmit antenna of an uplink signal. The specific selection method is as described in mode 2. In this way, according to this mode, since the antenna selection method is varied corresponding to the distance between the mobile station and the base station, a mobile station which is thought to cause interference in the adjacent cell selects an antenna that causes the least interference in the adjacent cell as a transmitting antenna, while a mobile station that is judged to cause the least interference in the adjacent cell is able to select an antenna with the best state of the propagation path as a transmission antenna, and in this way it is possible to realize the selection diversity of antenna with high efficiency in the complete communication system. In addition, the modalities described above describe the mobile communication system including two base stations, the base station 1, and the base station 2, as an example, but the invention is applicable to a mobile communication system which includes three or more base stations. When three or more base stations are included, one of the base stations in the other cells is selected as a target base station for reduction or interference, and the same processing as the previous one can be performed with the selected base station assumed as the base station 2 in the modalities mentioned above. As a method for selecting a base station, for example, a method for selecting a base station in which the mobile station causes the greatest interference, i.e., a base station that provides the highest reception power in the mobile station in the TDD scanner, (2) a method for selecting a base station that causes the highest interference, (3) a method for selecting a base station with the highest proportion of capacity (the number of users retained / the maximum number of permissible users), and similar. In this case, the base station (base station 1) in the current communication receives information reports of the interference status and the capacity ratio of the adjacent base stations, and based on the information, selects a target base station for reduction of interference. The base station in the current communication notifies the mobile station of the selected target base station for interference reduction. Each of the functional blogs used in the descriptions of each of the aforementioned modalities is typically implemented as an LSI which is an integrated circuit. Each of the blocks can be configured in the form of a chip, or a chip can include part or all of the blogs. Agui, LSI is assumed, but the circuit can be referred to as an IC, LSI system, LSI super, LSI ultra or similar that corresponds to the degree of integration. Additionally, the method of integrating circuits is not limited to the LSI, and can be achieved by a dedicated circuit or general processor. It may be possible to use FPGA (Field Programmable Gate Array) that allows programming after LSI fabrication, a reconfigurable processor that allows reconfiguration of the connection or adjustment in the circuit cell within the LSI , or similar. Additionally, if the technique to integrate circuits that substitute the LST with progress in the semiconductor technique or another derived technique arises, the functional blocks will be integrated naturally using this technique. The adaptation of biotechnology and the like may have the potential. The present application is based on Japanese Patent Application No. 2004-051587 filed on February 26, 2004, the full content of which is expressly incorporated by reference herein. Industrial Applicability The present invention is suitable for an apparatus of mobile radio communication stations and the like used in a mobile communication system. It is noted that in relation to this date, the best method known to the applicant to carry out the present invention is that which is clear from the present description of the invention.

Claims (8)

2. Having described the invention as above, the content of the following claims is claimed as property: 1. Mobile station apparatus, characterized by comprising: a plurality of antennas that receive both a signal transmitted from a first base station and another signal transmitted from a second base station of an adjacent cell which is adjacent to a cell of the first base station; a selection station that selects the antenna that causes the least interference in the adjacent cell from among the plurality of antennas; and a transmission section transmitting a signal to the first base station of the selected antenna. Mobile station apparatus according to claim 1, characterized in that the selection section selects the antenna that causes the least interference in the adjacent cell from among the plurality of antennas that the mobile station has when a distance between the mobile station and the first base station is more or equal to a threshold.
3. 3: mobile station apparatus according to claim 1, characterized in that it further comprises: a measurement section that measures the reception power of the signal transmitted from the first base station for each of the plurality of antennas that the mobile station has; and a determination section that, for each of the plurality of antennas that the mobile station has, determines a modulation coding scheme usable from a plurality of modulation coding schemes prepared in advance according to the reception power measure, wherein the selection section selects the antenna that causes the least interference in the adjacent cell from among the plurality of antennas that the mobile station has when the usable modification coding schemes are the same in the plurality of antennas that the mobile station.
4. 4. Mobile station apparatus according to claim 1, characterized in that it further comprises: a measurement section that measures the reception power of the signal transmitted from the second base station, for each of the plurality of antennas that the station has mobile, wherein as the antenna that causes the least interference to the adjacent cell, the selection section selects an antenna with the lowest reception power measured in the measurement section from among the plurality of antennas that the mobile station has.
5. 5. Mobile station apparatus according to claim 1, characterized in that it further comprises: a measurement section that measures the reception power of signals transmitted from a plurality of antennas that the second base station has, for each of the plurality of antennas that the mobile station has and for each one of the plurality of antennas that the second base station has; and a combination section combining the measured reception power for each of the plurality of antennas that it has in the mobile station to obtain the combined reception power, wherein as the antenna that causes the least interference in the adjacent cell, the selection section selects an antenna with the lowest combined reception power among the plurality of antennas that the mobile station has.
6. 6. Mobile station apparatus according to claim 1, characterized in that it further comprises: a first measuring section that measures the reception power of the signal transmitted from the first base station for each of the plurality of antennas that the station has mobile; and a second measurement section that measures the reception power of the signal transmitted from the second base station for each of the plurality of antennas that the mobile station has; and a calculation section that calculates a ratio of the reception power measured in the second measurement section to the reception power measured in the first measurement section for each of the plurality of antennas that the mobile station has, wherein as the antenna causing the least interference in the adjacent cell, the selection section selects an antenna with the lowest ratio calculated in the calculation section of - among the plurality of antennas that the mobile station has. .
7. Mobile station apparatus according to claim 1, characterized in that it further comprises: a first measurement section that measures the reception power of the signals transmitted from a plurality of antennas that the first base station has, for each of the plurality of antennas that the mobile station has and for each one of the plurality of antennas that the first base station has; a second measurement section that measures the reception power of the signals transmitted from a plurality of antennas that the second base station has, for each of the plurality of antennas that the mobile station has and for each of the plurality of antennas that it has the second base station; a combination section combining the reception power measured in the first measurement section and the reception power measured in the second measurement section for each of the plurality of antennas that the mobile station has and for each base station to obtain the combined reception power; and a calculation section that calculates a ratio of the combined reception power in the second base station to the combined reception power in the first base station for each of the plurality of antennas that the mobile station has, wherein as the antenna which causes the least 'interference in the adjacent cell, the selection section selects an antenna with the lowest ratio calculated in the calculation section from among the plurality of antennas that the mobile station has.
8. 8. Method for selecting a transmission antenna in a mobile station apparatus having a plurality of antennas, characterized in that the antenna causing the lowest interference in an adjacent cell is selected from among the plurality of antennas as a transmission antenna, the adjacent cell is adjacent to a cell of the base station to which the mobile station apparatus transmits a signal.

   SUMMARY OF THE INVENTION

   A mobile station apparatus that allows increases in the capacity of the communication system when high-speed uplink packets and the like are communicated. The mobile station having a plurality of antennas, antenna 1 and antenna 2, compares the reception power of a signal r? received at antenna 1 with the reception power of a signal r22 received at antenna 2 between signals transmitted from base station 2 of an adjacent cell, selects antenna 1 as a transmit antenna when "the receiving power of r2 ? less than the reception power of r22", while selecting the antenna 2 as a transmission antenna when" the reception power of r2? = the reception power of r22, transmits an uplink signal to the station base 1 of the selected antenna, and reduces the interference caused in the base station of the adjacent cell.

   Data reception

   Data transmission

   FIG2