USO08072916B2
`
`(12) United States Patent
`Dateki
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 8,072,916 B2
`Dec. 6, 2011
`
`(54) MOBILE WIRELESS COMMUNICATION
`SYSTEMAND WIRELESS COMMUNICATION
`APPARATUS USING TRANSMISSION POWER
`CONTROL INFORMATION
`
`EP
`EP
`JP
`
`FOREIGN PATENT DOCUMENTS
`1206 047
`5, 2002
`1351 411
`10, 2003
`11-145901
`5, 1999
`
`(75) Inventor: Takashi Dateki, Kawasaki (JP)
`(73) Assignee: Fujitsu Limited, Kawasaki (JP)
`(*) Notice:
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 296 days.
`(21) Appl. No.: 11/114,817
`(22) Filed:
`Apr. 26, 2005
`
`(65)
`
`(30)
`
`Prior Publication Data
`US 2006/O171342 A1
`Aug. 3, 2006
`
`Foreign Application Priority Data
`
`Jan. 14, 2005 (JP) ................................. 2005-007508
`
`(51) Int. Cl.
`(2006.01)
`H04B 7/85
`(52) U.S. Cl. ........ 370/318; 370/332: 370/333; 370/342:
`37Of 441
`(58) Field of Classification Search .................... 455/69,
`455/70, 88,522; 370/342, 441, 318,332,
`370/333
`See application file for complete search history.
`
`(56)
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`6,374,118 B1 * 4/2002 Toskala et al. ................ 455,522
`6,611,508 B1
`8, 2003 Abe
`6,647,005 B1 * 1 1/2003 Cao et al. ...................... 370,342
`6,980,808 B1* 12/2005 Smith ..............
`455,450
`2002/0018527 A1
`2/2002 Vanderaar et al. ............ 375,259
`2003/008 1586 A1* 5/2003 Malladi et al. ................ 370,345
`2004/0066772 A1* 4/2004 Moon et al. ................... 370,342
`2006/0221809 A1 * 10, 2006 Malladi et al. ................ 370,206
`
`OTHER PUBLICATIONS
`European Search Report dated Mar. 21, 2006.
`Ari Hottinen et al. Multi-Antenna Transceiver Techniques for 3G and
`Beyond. 2003.
`3" Generation Partnership Project; Technical Specification Group
`Radio Access Network, Physical Channels and mapping of transport
`channels onto physical channels (FDD) Release 5.
`(Continued)
`
`Primary Examiner — Olumide TAjibade Akonai
`Assistant Examiner — Jaime Holliday
`(74) Attorney, Agent, or Firm — Katten Muchin Rosenman
`LLP
`
`ABSTRACT
`(57)
`A mobile wireless communication system including a wire
`less communication apparatus and a counterpart wireless
`communication apparatus is provided, the system establish
`ing wireless communication between the wireless communi
`cation apparatus and the counterpart wireless communication
`apparatus by multiplexing plural channels including at least a
`traffic channel for transmitting a packet, a control channel for
`transmitting control information for receiving the packet, and
`a channel for transmitting information including transmis
`sion power control information. The wireless communication
`apparatus includes a transmission unit that transmits the
`transmission control information to the counterpart wireless
`communication apparatus via the channel for transmitting
`information including transmission power control informa
`tion at intervals of a prescribed period that is longer than a
`length of the packet, and transmits the transmission power
`control information via the control channel when the packet is
`being transmitted via the traffic channel.
`
`19 Claims, 6 Drawing Sheets
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`OTHER PUBLICATIONS
`3' Generation Partnership Project; Technical Specification Group
`Radio Access Network; Multiplexing and Channel Coding (FDD)
`Release 5.
`3rd Generation Partnership Project; Technical Specification Group
`Radio Access Network; Spreading and modulation (FDD) (Release
`5).
`
`3rd Generation Partnership Project; Technical Specification Group
`Radio Access Network; Physical Layer procedures (FDD) (Release
`5).
`TSG-RAN Working Group I meeting #34 031073 Fractional Dedi
`cated Physical Channel, Discussion on Multiplexing Options, Oct.
`2003.
`* cited by examiner
`
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`Sheet 1 of 6
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`US 8,072,916 B2
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`1.
`MOBILE WIRELESS COMMUNICATION
`SYSTEMAND WIRELESS COMMUNICATION
`APPARATUS USING TRANSMISSION POWER
`CONTROL INFORMATION
`
`BACKGROUND OF THE INVENTION
`
`2
`In the W-CDMA scheme, HSDPA (High Speed Downlink
`Packet Access) for realizing a maximum downlink transmis
`sion speed of 14 Mbps is defined. According to this scheme,
`adaptive coding modulation is used for packet transmission.
`For example, QPSK (Quadrature Phase Shift Keying) modu
`lation and 16-QAM (Quadrature Amplitude Modulation)
`may be adaptively interchanged to realize a transmission rate
`in accordance with the state of the wireless propagation path.
`It is noted that HSDPA uses the H-ARQ (HybridAutomatic
`Repeat Request) scheme. For example, in the mobile wireless
`communication system of FIG. 1, when the mobile station
`50c receives packet data from the base station 50a and detects
`an error, the mobile station 50c sends a request to the base
`station 50a to retransmit the packet data. In turn, the base
`station 50a conducts retransmission of the packet data, and
`the mobile station 50c conducts an error correction decoding
`process using both the initially received data and the retrans
`mitted data.
`Also, it is noted that wireless channels such as HS-SCCH
`(High Speed-Shared Control Channel), HS-PDSCH (High
`Speed-Physical DownlinkShared Channel), and HS-DPCCH
`(High Speed-Dedicated Physical Control Channel) are used
`in HSDPA.
`The wireless channels HS-SCCH and HS-PDSCH in a
`mobile wireless communication system correspond to down
`link shared channels from the base station to the mobile
`station. The HS-SCCH corresponds to a control channel for
`transmitting parameter information pertaining to data trans
`mitted by the HS-PDSCH. The parameter information may
`include modulation type information indicating the modula
`tion method used in transmitting data via the HS-PDSCH, the
`diffusion code number, and pattern information for a rate
`matching process that is conducted on transmission data, for
`example.
`The HS-DPCCH in the mobile wireless communication
`system corresponds to an uplink dedicated control channel
`from the mobile station to the base station, and is used upon
`transmitting from the mobile station to the base station an
`ACK signal or a NACK signal indicating whether data
`received via the HS-PDSCH are properly received. For
`example, in a case where CRC erroris detected in the received
`data, a NACK signal is transmitted to the base station, and the
`base station conducts retransmission of the data in response to
`the NACK signal. Also, the HS-DPCCH is used to measure
`the reception quality (e.g., SIR: Signal to Interference Ratio)
`of a signal received from the base station, and periodically
`transmit the measurement result to the base station as a COI
`(Channel Quality Indicator). The base station determines the
`state of the downlink wireless environment based on the CQI,
`and when it is determined that the wireless environment is in
`a good State, the base station Switches to a modulation method
`that enables data transmission at a higher speed. On the other
`hand, when it is determined that the wireless environment is
`not in a good state, the base station Switches to a modulation
`method that realizes data transmission at a lower speed.
`FIG. 2 is a diagram showing the channels used in HSDPA.
`In this drawing, the wireless channels CPICH, P-CCPCH,
`HS-SCCH, HS-PDSCH, HS-DPCCH are shown. It is noted
`that the CPICH (Common Pilot Channel) and the P-CCPCH
`(Primary Common Control Physical Channel) correspond to
`downlink shared channels. The CPICH corresponds to a
`channel used for channel estimation and cell search at the
`mobile station, and as a timing reference of other downlink
`physical channels within the same cell; that is, the CPICH
`corresponds to a channel for transmitting the so-called pilot
`signal. The P-CCPCH corresponds to a channel for transmit
`ting report information. The channels HS-SCCH, HS-PD
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`1. Field of the Invention
`The present invention relates to a mobile wireless commu
`nication system and a wireless communication apparatus that
`establishes wireless communication by controlling transmis
`sion power according to transmission power control informa
`tion.
`2. Description of the Related Art
`A mobile wireless communication system that establishes
`wireless communication between wireless communication
`apparatuses such as a mobile station and a base station may
`have a configuration as is shown in FIG.1. The mobile wire
`less communication system of FIG. 1 includes plural base
`stations 50a and 50b as wireless communication apparatuses
`that are located in different areas, and a mobile station 50c
`that conducts wireless communication while moving within
`the service areas of the base stations 50a and 50b. The base
`stations 50a and 50b and the mobile station 50c include
`antennas 51a, 51b, and 51c, transmission/reception units 53a,
`53b, and 53c that include amplifiers, modulators, and
`demodulators, for example, and signal processing units 54a,
`54b, and 54c, respectively. Also, the base stations 50a and 50b
`include interface units 52a and 52b, respectively, that form
`interfaces with a network (not shown).
`The wireless communication scheme used in the wireless
`communication between the mobile station 50c and the base
`stations 50a and 50b may correspond to the W-CDMA (Wide
`Code Division Multiple Access) scheme, the OFDM (Or
`thogonal Frequency Division Multiplexing) Scheme, or other
`various schemes. Also, it is noted that transmission power
`control (TPC) information is transmitted from the base sta
`tions 50a and 50b to the mobile station 50c at predetermined
`intervals via downlink channels (dedicated channels) so that
`a signal transmitted from the mobile station 50c to the base
`stations 50a and 50b may be received with a suitable power
`that is sufficient for proper signal reception but is below a
`level that may cause interference with other channels. Based
`on the transmission power control information, the mobile
`station 50c conducts transmission power control to increasef
`decrease the transmission power of the transmission/recep
`tion unit 53c. The transmission power control information is
`generated according to the reception level (quality) of a signal
`Such as a pilot signal that is transmitted from the mobile
`station 50c. For example, when the reception level (quality) is
`high, control information directing a decrease of the trans
`mission power may be generated, and when the reception
`level (quality) is low, control information directing an
`increase of the transmission power may be generated.
`In a mobile wireless communication system that realizes
`packet communication, an ACK signal is transmitted when a
`packet is properly received, and a NACK signal is transmitted
`when a packet cannot be properly received, the signals being
`transmitted via a dedicated channel. In such a system, even
`when packet transmission is rarely conducted, and transmis
`60
`sion of reception response signals such as ACK and NACK
`signals is not necessary, a signal Such as a pilot signal is
`continually transmitted via another dedicated channel for
`Suitably adjusting the transmission power of the dedicated
`channel used for transmitting the reception response signals
`such as ACK and NACK signals. Thus, the mobile station
`unnecessarily consumes power for transmitting Such signals.
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`SCH, and HS-DPCCH correspond to control channels as
`described above, and the HS-DPCCH is used to transmit the
`CQI and ACK/NACK signals.
`In the illustrated example of FIG. 2, 15 slots make up one
`frame (10 ms), and since the CPICH is used as a timing
`reference, the beginning (head) of the frames of the channels
`P-CCPCH and HS-SCCH correspond to the beginning (head)
`of the frame of CPICH; however, the beginning (head) of the
`frame of the HS-PDSCH is delayed by two slots. Sucha delay
`is made so that the mobile station may receive and identify
`information pertaining to demodulation of the HS-PDSCH
`beforehand. That is, information pertaining to the modulation
`method and diffusion code is provided beforehand via the
`HS-SCCH so that demodulation and decoding of the HS
`PDSCH may be suitably realized. Also, it is noted that in the
`15
`channels HS-SCCH and HS-PSDCH, three slots makeup one
`sub frame.
`According to 3GPP TS 25.212 v.5.7.0 (3rd Generation
`Partnership Project; Technical Specification Group Radio
`Access Network; Multiplexing and Channel Coding (FDD)),
`the HS-SCCH represents the following information items:
`(a) Xccs (Channelization Code Set Information); 7 bits:
`information on the diffusion code used for the HS-PDSCH;
`(b) Xms (Modulation Scheme Information); 1 bit; modu
`lation method used for the HS-PDSCH:
`25
`(c) Xtbs (Transport-Block Size Information); 6 bits; trans
`mission data block size for error correction coding:
`(d) Xhap (Hybrid-ARQ Process Information); 3 bits; pro
`cess number for conducting retransmission control;
`(e) Xrv (Redundancy and Constellation Version); 3 bits:
`parameter for rate matching;
`(f) Xnd (New Data Indicator); 1 bit; information indicating
`whether data corresponds to new data; and
`(g) Xue (UE Identity); 16 bits; user identification informa
`tion.
`As can be appreciated from the above descriptions, the
`HS-SCCH is made up of 37 bits, and by receiving the HS
`SCCH, parameter information pertaining to the modulation
`method, the diffusion code, and error correction, for example,
`may be identified. In turn, demodulation and decoding of the
`HS-DSCH may be conducted according to the parameter
`information.
`The information (a) Xccs represents information on the
`diffusion code used in transmitting data via the HS-PDSCH.
`For example, XccS may represent a combination of the multi
`code number and code offset. The information (b) Xms indi
`cates the modulation method being used, and for example,
`Xms may correspond to 1 or 'O' depending on whether the
`current modulation method corresponds to QPSK modula
`tion or 16-QAM. The information (c) Xtbs corresponds to
`data for calculating the data size for transmitting a Sub frame
`of the HS-PDSCH. The information (d) Xhap represents a
`process number for H-ARO, and corresponds to a consecu
`tive number with respect to that of a previously transmitted
`data block. It is noted that in the case of a retransmission
`process, the same process number assigned to the previously
`transmitted data block is used.
`The information (e) Xrv represents redundancy parameter
`or constellation parameter information in the retransmission
`of the HS-PDSCH. It is noted that in some cases, the param
`eter information may be updated upon transmission or
`retransmission, and in other cases, the parameter information
`may be left as it is. The information (f) Xnd corresponds to
`data indicating whether the transmitted block corresponds to
`a new data block or a retransmitted data block. For example,
`in the case of a new block, 1 and O may be interchanged,
`and in the case of a retransmitted block, the arrangement of
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`1 and O may be left unchanged. The information (g) Xue
`corresponds to identification information of the mobile sta
`tion (user).
`By receiving the HS-SCCH, parameter information per
`taining to the modulation method, the diffusion code, and
`error correction used at the HS-PDSCH may be identified,
`and demodulation and decoding of the HS-PDSCH may be
`conducted (e.g., see “Multi-Antenna Transceiver Techniques
`for 3G and Beyond’ by Ari Hottinen, Olav Tirkkonen, and
`Risto Wichman; 3GPP TS 25.211, Physical Channels and
`Mapping of Transport Channels onto Physical Channels
`(FDD), V. 5.5.0, 3GPP TS 25.213, Spreading and Modulation
`(FDD), V. 5.5.0; and 3GPP TS 25.214, Physical Layer Proce
`dures (FDD), V. 5.7.0).
`Also, to enhance the W-CDMA system, use of the F-DPCH
`(Fractional Dedicated Physical Channel) is proposed (e.g. see
`3GPP R1-031073). According to this technique, the same
`diffusion code is assigned to the pilot signals and transmis
`sion power control (TPC) information of a dedicated channel
`for plural users, and transmission is conducted through time
`division multiplexing within the same slot.
`Generally, a mobile station (user) that receives data via a
`shared channel (traffic channel) such as the HS-PDSCH
`transmits traffic data via the HS-PDSCH, and thereby, data to
`be transmitted via the dedicated channel (e.g., DPCH as
`opposed to an HS channel) are virtually non-existent at Such
`a mobile station. Nonetheless, TPC bits and pilot signals have
`to be transmitted in order to conduct transmission power
`control, and thereby, the dedicated channel (DPCH) and the
`HS-PDSCH have to be connected at the same time. In this
`case, a code is occupied even when data transmission does not
`have to be conducted, and when plural mobile stations (users)
`in similar situations exist, a deficiency in code resources may
`be created. In response to Such a problem, the technique
`implementing the F-DPCH involves using the same code to
`conduct a diffusion process and time division multiplexing
`with respect to TPC bits and pilot signals of plural users that
`have no transmission data to be transmitted through a dedi
`cated channel.
`Also, as another measure for countering a deficit of code
`resources, Japanese Laid-Open Patent Publication No.
`11-145901 discloses a wireless communication apparatus
`that conducts transmission power control through providing a
`dedicated power control channel, embedding TPC bits of
`plural users into the transmission power control channel
`through time division multiplexing, and embedding identical
`TPC bits into traffic channels for conducting packet transmis
`Sion, wherein when a packet to be transmitted is generated,
`the TPC bits of the power control channel is converted into
`invalid information so that the TPC bits of the traffic channel
`is prioritized.
`In the W-CDMA scheme, transmission power control
`(TPC) of a dedicated channel (DPCH) is conducted via an
`uplink channel. The transmission power control (TPC)
`involves controlling the transmission power of the mobile
`station by feeding back transmission control information
`referred to as TPC bits in slot units from the base station to the
`mobile station. On the other hand, in a packet communication
`scheme using shared channels such as the HS-PDSCH, pilot
`signals and TPC bits are periodically transmitted via uplink
`and downlink DPCH channels so that transmission powerfor
`transmitting a reception response signal is adjusted to a Suit
`able levelata mobile station even when data are not addressed
`to the mobile station. In such a case, code resources have to be
`used for transmission power control of the respective dedi
`cated channels, and thereby, a deficiency in code resources is
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`created. Also, since the mobile station has to transmit pilot
`signals on a constant basis, a large amount of power is con
`Sumed as a result.
`Also, a technique is proposed in the prior art that uses the
`F-DPCH in the W-CDMA scheme to integrate plural
`A-DPCH channels through time division multiplexing for
`realizing efficient use of code resources. However, since
`transmission power control (TPC) bits are transmitted in slot
`units, multiplexing may not be conducted for a large number
`of users. That is, according to this technique, a large number
`of mobile stations conducting packet transmission cannot be
`accommodated within the same area. Also, according to this
`technique, it is assumed that a signal is transmitted on a
`constant basis via the uplink channel. That is, the mobile
`station is arranged to transmit a signal Such as a pilot signal
`for realizing transmission power control regardless of
`whether packet transmission is conducted. This arrangement
`is disadvantageous from the point of view of power conser
`vation. It is noted that the mobile station uses a relatively
`Small battery as a power source to conduct transmission/
`reception processes, and thereby, it is desired that power
`consumption be reduced in order to realize packet transmis
`sion for a long period of time.
`Also, in the prior art technique involving the use of a power
`control channel and a traffic channel for transmitting TPC
`bits, when the TPC bits are transmitted via the traffic channel,
`the TPC bits at the power control channel have to be invali
`dated in order to prevent generation of a conflict. Such pro
`cesses may be quite complicated thereby leading to high
`power consumption. Also, since the power control channel is
`arranged to be transmitted when a transmission control
`packet does not exist and is therefore not transmitted on a
`periodic basis, power control may not be stabilized.
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`SUMMARY OF THE INVENTION
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`power control information and right after receiving the trans
`mission power control information transmitted from the wire
`less communication apparatus via the control channel.
`In another preferred embodiment of the present invention,
`the transmission power control information transmitted from
`the wireless communication apparatus to the counterpart
`wireless communication apparatus includes first transmis
`sion power control information that is transmitted via the
`channel for transmitting information including transmission
`power control information and second transmission power
`control information that is transmitted via the control chan
`nel, and the transmission unit of the counterpart wireless
`communication apparatus transmits the pilot signal at peri
`odic intervals shorter than a transmission period at which the
`first transmission power control information is transmitted.
`In another preferred embodiment of the present invention,
`the transmission power control information transmitted from
`the wireless communication apparatus to the counterpart
`wireless communication apparatus includes first transmis
`sion power control information that is transmitted via the
`channel for transmitting information including transmission
`power control information and second transmission power
`control information that is transmitted via the control chan
`nel, and a transmission power control level represented by the
`second transmission power control information is arranged to
`be greater than or equal to a transmission power control level
`represented by the first transmission power control informa
`tion.
`According to another aspect of the present invention, a
`wireless communication apparatus is provided that is config
`ured to transmit data within a mobile wireless communication
`system that realizes data transmission via a shared channel,
`the apparatus including:
`a transmission unit that is configured to transmit to a
`mobile station first transmission power control information at
`intervals of a prescribed period, and transmit control infor
`mation for receiving the data including second transmission
`power control information when transmitting the data to the
`mobile station.
`In a preferred embodiment of the present invention, a trans
`mission power control level represented by the second trans
`mission power control information that is included in the
`control information is arranged to be greater than or equal to
`a transmission power control level represented by the first
`transmission power control information that is transmitted at
`intervals of the prescribed period.
`According to another aspect of the present invention, a
`wireless communication apparatus is provided that is config
`ured to receive data within a mobile wireless communication
`system that realizes data transmission via a shared channel,
`the apparatus including:
`a transmission unit that is configured to transmit a pilot
`signal in conjunction with receiving control information for
`receiving the data.
`In a preferred embodiment of the present invention, the
`transmission unit is further configured to transmit the pilot
`signal at intervals of a prescribed period, and the transmission
`of the pilot signal in conjunction with the reception of the
`control information is conducted at periodic intervals shorter
`than the prescribed period.
`According to an aspect of the present invention, transmis
`sion power control information is transmitted at prescribed
`periodic intervals via a channel for transmitting information
`including the transmission power control information, and
`when packet transmission is conducted, transmission power
`control information is also transmitted via a control channel.
`When packet transmission is not conducted, the transmission
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`Ex.1005 / Page 11 of 17Ex.1005 / Page 11 of 17
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`TESLA, INC.TESLA, INC.
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`The present invention has been conceived in response to
`one or more of the problems of the related art, and its object
`is to enable transmission power control with low power con
`Sumption and high accuracy.
`40
`According to an aspect of the present invention, a mobile
`wireless communication system is provided that includes:
`a wireless communication apparatus and a counterpart
`wireless communication apparatus; wherein
`wireless communication is established between the wire
`less communication apparatus and the counterpart wireless
`communication apparatus by multiplexing a plurality of
`channels including at least a traffic channel for transmitting a
`packet, a control channel for transmitting control information
`for receiving the packet, and a channel for transmitting infor
`mation including transmission power control information;
`and
`the wireless communication apparatus includes a transmis
`sion unit that transmits the transmission control information
`to the counterpart wireless communication apparatus via the
`channel for transmitting information including transmission
`power control information at intervals of a prescribed period
`that is longer than a length of the packet, and transmits the
`transmission power control information via the control chan
`nel when the packet is being transmitted via the traffic chan
`nel.
`In a preferred embodiment of the present invention, the
`counterpart wireless communication apparatus includes a
`transmission unit that transmits a pilot signal right before
`receiving the transmission power control information trans
`mitted from the wireless communication apparatus via the
`channel for transmitting information including transmission
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`US 8,072,916 B2
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`7
`power control information is transmitted via the channel for
`transmitting information including transmission power con
`trol information at prescribed periodic intervals that are set to
`be relatively long, thereby enabling conservation of power.
`According to an embodiment of the present invention, a pilot
`signal is transmitted at prescribed periodic intervals rather
`than being continuously transmitted, and the packet signal is
`also transmitted upon indicating the presence of a packet for
`transmission to thereby enable further power conservation.
`According to an embodiment of the present invention, the
`transmission power control information includes first trans
`mission power control information that is transmitted via the
`channel for transmitting information including transmission
`power control information and second transmission power
`control information that is transmitted via the control chan
`nel, and a transmission power control level represented by the
`second transmission power control information is arranged to
`be greater than that represented by the first transmission
`power control information to improve responsiveness of the
`transmission power control operation.
`According to another aspect of the present invention, by
`transmitting the transmission power control information at
`prescribed periodic intervals, the transmission power control
`information may be included in the control information for
`receiving data while maintaining stability in the transmission
`power control operation, and the transmission power control
`information may be transmitted in conjunction with data
`transmission.
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`transmission control information to the counterpart wireless
`communication apparatus corresponding to the mobile sta
`tion, for example, via the channel for transmitting informa
`tion including transmission power control information at
`intervals of a prescribed period that is longer than the length
`of the packet, and transmits the transmission power control
`information via the control channel when the packet is being
`transmitted via the traffic channel.
`A wireless communication apparatus according to an
`embodiment of the present invention corresponds to a wire
`less communication apparatus Such as a base station of a
`mobile wireless communication system, and includes a trans
`mission unit that is configured to transmit to a mobile station
`via a dedicated channel first transmission power control infor
`mation at intervals of a prescribed period that is longer than a
`length of a packet transmitted by a traffic channel, and trans
`mit second transmission power control information via a
`control channel when transmitting the packet via the traffic
`channel.
`It is noted that the transmission power control information
`in the following descriptions is assumed to be. valid informa
`tion (to be used at the reception side).
`FIG. 3 is a diagram showing an exemplary configuration of
`a wireless communication apparatus according to an embodi
`ment of the present invention. The wireless communication
`apparatus of FIG.3 may correspond to a wireless communi
`cation apparatus such as a base station of a mobile wireless
`communication system implementing the CDMA scheme
`that includes at least a wireless communication apparatus and
`a counterpart wireless communication apparatus. According
`to the present example, the wireless communication appara
`tus includes antennas 1 and 21, a high frequency processing
`unit (RFIF) 2, a multiplexing unit 3, multiplying units 4, 5,
`and 6, diffusion units 7, 8, and 9, a symbol mapping un