1||||l Illlllll III lllll ll||| |l|l| Illll lllll lllll |l|l| lllll Illlll III III" |ll|
`USOO5583851A
`[11] Patent Number:
`5,583,851
`[45] Date of Patent:
`Dec. 10, 1996
`
`United States Patent 1191
`Kato et al.
`
`[54] MOBILE COMMUNICATION APPARATUS
`HAVING MULTLCODES ALLOCATING
`FUNCTION
`
`[75]
`
`[73]
`
`Inventors: Osamu Kato; Nobuo Asano, both of
`Yokohama, Japan
`
`Assignee: Matsushita Electric Industrial Co.,
`Ltd., Osaka, Japan
`
`[21]
`
`Appl. No.: 272,158
`
`[22] Filed:
`
`JUL 8, 1994
`.
`.
`.
`.
`.
`Forelgn Apphcatwn Pmmty Data
`[30]
`Jul. 16, 1993
`[JP]
`Japan .................................. .. 5-199014
`Jul. 16, 1993
`[JP]
`Japan .................................. .. 5-199017
`6
`
`""""""""""""""
`[gé] L1;
`’
`‘
`‘ """"" "
`[
`1
`_'
`'
`[58] Fleld 0f Search ................................ .. 370/18, 19, 21,
`370/22’ 84’ 112; 375/200’ 205’ 206’ 40’
`96’ 100; 371/381’ 39-1’ 44’ 45’ 37-1
`_
`References Clted
`Us. PATENT DOCUMENTS
`_
`_
`5,166,951 11/1992 SChllllIlg ............................... .. 375/200
`5,235,612
`8/1993 Stilwell et al.
`375/200
`5,235,614
`8/1993 Bruckert et a1.
`.... .. 370/18
`5,291,515
`3/1994 Uchida et al. ...................
`375/200
`
`[56]
`
`5,309,474
`5/1994 Gilhousen m1. ..................... .. 370/18
`5,410,568
`4/1995 Schilling ................................. .. 370/18
`Primary Examiner—Douglas W. Olms
`Assistant Examiner—Chau T. Nguyen
`Attorney, Agent, or Firm—Spencer & Frank
`
`[57]
`
`ABSTRACT
`
`A mobile communication unit which can perform a high-bit
`rate information transmission by allocating a plurality of
`channel numbers to a user who carries out a high-bit rate
`communication. The mobile communication unit includes a
`set of units at the transmitter side 21 and a set of units at the
`receiver side 22, to carry out communications by allocating
`spread codes to channels within the same cell. A plurality of
`charmel numbers are allocated to one user. The transmitter
`side units include the separating unit 23 for separating the
`user information, the spread modulator 30 for spread pro
`cessing the separated information by using the spread codes
`corresponding to the respective channel numbers, and the
`combining unit 31 for Combining the di?rused information
`and outputting the combined information to the receiver side
`unit. The receiver side units include the despreader 32 for
`despread the diifused information by using the spread codes
`of the respective channel numbers allocated to the user, and
`the multiplexing unit 33 for combining the despreaded
`information of the plurality of channels. Thus, a high-bit rate
`transmission Service is provided
`
`3 Claims, 5 Drawing Sheets
`
`I ————————————————————————— - — 1
`
`51
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`
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`
`1 __________________ _ _1'
`P1101 ‘42 UNITS AT THE RECEIVER 510E
`
`ERIC-1006
`Ericsson v. IV
`Page 1 of 12
`
`

`
`US. Patent
`
`Dec. 10, 1996
`
`Sheet 1 of 5
`
`5,583,851
`
`FIG.| PRIOR ART
`9
`T- ------------- +1
`INFORMQTIION:
`SPREA
`'06
`i
`D
`B [bps]? MODULATOR
`I
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`Btbps] 4/ MODULATOR
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`SIDE
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`
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`
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`
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`
`F l G . 2
`PRIOR ART
`
`usER
`NLMBER
`
`CHANNEL
`NUMBER
`
`ORTHOGONAL
`@855”
`
`SPREAD
`8’ PN SER'ES _’c0DE
`
`#l
`#2
`
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`
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`wzm _ ®
`
`PN(t) —- Sl(t)
`PN(t) —-> 82H)
`
`Page 2 of 12
`
`

`
`US. Patent
`
`Dec. 10, 1996
`
`Sheet 2 of 5
`
`5,583,851
`
`Fl G . 3
`
`USER SIGNAL
`SPECTRUM |2
`\
`
`+
`
`\
`
`POWER SPECTRUM
`DENSITY P
`
`<---—-’ BAND WIDTH B
`
`FIG.4
`
`l
`
`SPREAD MULTIPLE SPECTRUM
`
`P SPREAD
`BAND WIDTH S
`
`FIG.5
`
`DESIRED WAVE
`l4 \_
`
`‘5 INTERFERENCE WAVE
`COMPONENTS
`
`J
`
`Page 3 of 12
`
`

`
`US. Patent
`
`Dec. 10, 1996
`
`Sheet 3 of 5
`
`5,583,851
`
`F l G. 6
`
`28
`ii____~___._,
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`
`‘22 UNITS AT THE RECENER SIDE
`
`m A m ]
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`s
`
`Page 4 of 12
`
`

`
`U.S. Patent
`
`Dec. 10,1996
`
`Sheet 4 of 5
`
`5,583,851
`
`USER
`
`CHANNEL
`
`NUMBER
`
`°"""'°G°"""-
`
`SPREAD
`
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`
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`
`USER
`NUMBER
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`NUMBER
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`
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`W2+n (t)
`
`-
`
`5
`
`-> S2+n<t)
`
`Page 5 of 12
`
`

`
`U.S. Patent
`
`Dec. 10, 1996
`
`Sheet 5 0f 5
`
`5,583,851
`
`F l G. 8
`
`I- _______________ ‘m7’ _ _ _ “ "'" __'“"I
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`LT“ __________________ ——1 ______ _ _J
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`
`Page 6 of 12
`
`

`
`5,583,851
`
`1
`MOBILE COMMUNICATION APPARATUS
`HAVING MULTI-CODES ALLOCATING
`FUNCTION
`
`BACKGROUND OF THE INVENTION
`
`1. Field of the Invention
`The present invention relates to a mobile communication
`unit for performing a high-quality information transmission
`by allocating a plurality of channel numbers to one user.
`1. Description of the Related Art
`In recent years, a code division multiple access mobile
`communication unit has been developed for practical appli
`cation, as described in the literature, “On the System Design
`Aspects of Code Division Multiple Access (CDMA)
`Applied to Digital Cellular and Personal Communications
`Networks, (May 19-22, 1991, IEEE Vehicular Technology
`Conference)”. The con?guration of the prior-art technique of
`the code division multiple access mobile communication
`unit is shown in FIG. 1. In FIG. 1, a symbol 1 designates a
`set of units at the transmitter side such as the base station or
`the like and 2 designates a set of units such as a car telephone
`set and a portable telephone set at the receiver side. Symbols
`3, 4 and 5 designate information input circuits provided
`corresponding to channel numbers allocated to each user for
`the set of units at the transmitter side, to which information
`of the respective users are inputted. An information input
`circuit 3 corresponds to #1, an information input circuit 4
`corresponds to #2, and an information input circuit 5 cor
`responds to #m. Symbols 6, 7 and 8 designate spread
`modulators connected to the information input circuits 3, 4
`and 5 respectively, for carrying out a spread processing in a
`spread code corresponding to each channel number. A sym
`bol 9 designates a combining unit for transmitting spread
`signals of a plurality of users by combining these spread
`signals together. A symbol 10 designates a despreader for '
`carrying out a despread processing in the spread code of the
`channel allocated to each user in the sets of units at the
`receiver side 2. In the set of units at the transmitter side 1,
`parameters W1(t), W2(t), - - -, and Wm(t) are inputted as
`orthogonal spread codes and a parameter PN(t) is inputted as
`a pseudo-noise series, to the spread modulators 6, 7 and 8,
`respectively. By multiplying these orthogonal spread codes
`by the pseudo-noise series, spread codes S1(t), S2(t), - - -,
`and Sm(t) corresponding to the respective channels are
`obtained, and spread processing is carried out in these spread
`codes. In the following explanation, the above pseudo-noise
`series will be referred to as “PN series”. In the set of units
`at the receiver side 2, each unit has the despreader 10. When
`the channel number of the receiver side units shown in FIG.
`1 is #i, a parameter Wi(t) is inputted as an orthogonal spread
`code and a parameter PN (t) is inputted as a PN series, to the
`despreader 10, respectively, so that a despread processing is
`carried out in the spread code corresponding to this channel.
`FIG. 2 shows an example of the spread codes to be used
`corresponding to the channel numbers allocated to the users
`in a certain cell for carrying out the spread and despread
`processings described above.
`In the mobile communication unit having the above
`described structure, when user information has been input
`ted from the information input circuits 3, 4 and 5 at a
`predetermined information transmission bit rate, for
`example, B [bps], a spread processing is carried out by the
`spread modulators 6, 7 and 8 in the spread code correspond
`ing to the channel numbers allocated to the users. Then, the
`combiner 9 combines the spread signals of the users and
`
`15
`
`25
`
`35
`
`45
`
`50
`
`55
`
`60
`
`65
`
`2
`transmits the combined result. In the mean time, when the
`combined spread signal has been received by the units at the
`receiver side 2, the despreader 10 carries out a despread
`processing by using the spread code corresponding to the
`channel number allocated to the user, so that the information
`is reproduced at the information transmission bit rate B [bps]
`and is then outputted from an information output circuit 11.
`FIGS. 3 to 5 show the status of changes in the waveform
`of a signal when the signal transmitted as user information
`at a certain information transmission bit rate is processed,
`transmitted and despreaded. The user information is inputted
`from the information input circuits 3, 4 and 5 in the form of
`a spectrum signal 12 having a band width B and a power
`spectrum density P as shown in FIG. 3. When the spectrum
`signal 12 has been spread processed by the spread modula
`tors 6, 7 and 8, the power within the band width B is
`distributed in a spread band width S of a spread multiple
`spectrum on the circuit shown in FIG. 4 to form a spread
`signal 13 as shown in FIG. 4. The spread modulators 6, 7 and
`8 correspond to the channel numbers allocated to the users
`and the spread codes are set to the respective channel
`numbers at different values as shown in FIG. 2. Therefore,
`the spread signal 13 takes a multiple structure with different
`values between channels. FIG. 4 shows an example of a
`four-channel spread multiple spectrum.
`In the unit at the receiver side 2, the spread signal 13 is
`despread processed in Wi(t) for the orthogonal spread code
`and PN(t) for the PN series. Therefore, of the four-channel
`spread multiple spectrum, the spread signal of the channel
`corresponding to the spread code Si(t), that is, the power of
`a desired wave, is concentrated to the band width B again,
`and the multiple other user signals (three channel compo
`nents) take the spreaded waveform. The waveform in the
`spreaded status remains as an interference wave. When a
`?ltering is applied to pass the band area B in the unit at the
`receiver side 2, a spectrum of a desired wave 14 and an
`interference wave 15 after the despread is obtained as shown
`in FIG. 5. When an SIR (a signal to interference ratio) which
`is the ratio of the power of the desired wave 14 to the power
`of the interference wave 15 takes a predetermined value,
`required communication quality can be maintained.
`When B=9600, that is, the information transmission bit
`rate is 9600 bps, at most 64 channels can be set within the
`range in which the SIR can secure a predetermined value,
`from the-viewpoint of an interference ratio. In this respect,
`there is an example that 64 kinds of Walsh code have been
`used as orthogonal spread code.
`According to the above-described prior-art mobile com
`munication unit, however, there has been a problem that the
`information transmission bit rate for one user that can be
`obtained is only not higher than the information transmis
`sion bit rate which corresponds to the value obtained by
`dividing the chip bit rate of the spread code by the spread
`rate, so that user information that is transmitted at a high
`information transmission bit rate can not be transmitted.
`
`SUMMARY OF THE INVENTION
`
`It is an object of the present invention to provide a mobile
`communication unit which can transmit information at a
`high-bit rate by allocating a plurality of channel numbers to
`the users who require a high-bit rate communications, to
`solve the above-described problems.
`In order to achieve the above object, the present invention
`provides a mobile communication unit having units at the
`transmitter side and units at the receiver side, for carrying
`
`Page 7 of 12
`
`

`
`5,583,851
`
`3
`out communications by allocating spread code, which are
`obtained by multiplying orthogonal spread code (number of
`series: m) by pseudo-noise series, to each channel within the
`same cell. For the channel numbers within the same cell,
`spread code which are obtained by multiplying m orthogonal
`spread codes by pseudo~noise series are corresponded, and
`a plurality (11 pieces) of channel numbers are allocated to one
`user. The units at the transmitter side include a separating
`unit for separating user information into n, spread modulat
`ing units for spread processing each of the information that
`has been separated in spread code corresponding to the
`channel number allocated to the user, and a combining unit
`for combining the spread processed information and output
`ting the combined result to the units at the receiver side. The
`receiver side units include despread units for despreading
`the spread processed information by using the spread codes
`of the channels allocated to the user, and a multiplexing unit
`for combining the despreaded information of n charmels.
`With the above-described structure, according to the
`present invention, when a high-bit rate information of nB
`bits/second (bps) has been transmitted to the user, at the
`transmitter side, the separating unit separates the user infor
`mation into n, and then the spread modulating units spread
`each of the n-separated user information at a bit rate B [bps]
`by using the spread codes corresponding to the channel
`numbers. Thus, spread signals of the user information are
`produced by n, and these spread signals are multiplexed into
`a spread multiple spectrum by the combining unit. The
`multiple spread spectrum is then transmitted to the receiver
`units. At the receiver side, n despread units despread the
`spread processed information, that has been spreaded at the
`bit rate B [bps], or the spread multiple spectrum, in the
`spread code of the channel numbers allocated to one user.
`The despread units then reproduce the received information
`by n channels, and the multiplexing unit combines the
`reproduced information of the n charmels into the original
`user information. In the above-described process, it is pos
`sible to provide a high-bit rate information transmission
`service of nB [bps]. Further, the structure for transmitting
`and receiving in the code division multiple access at the
`normal information transmission bit rate B [bps] (that is, the
`information transmission bit rate of the user to whom only
`one channel is allocated) can be applied straight to the
`receiver units. Functions required to be added to the trans
`mitting and receiving units for achieving the high-bit rate
`transmission are only the function for separating the nB
`[bps] information into nB [bps] information and the function
`for reverse multiplexing the information, which does not
`involve a substantial change of the structure. Further, by
`only setting the n to various values, it is possible to adapt to
`information transmission at various bit rates.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`15
`
`25
`
`35
`
`45
`
`50
`
`FIG. 1 is a block diagram for showing the con?guration
`of the prior-art mobile communication unit;
`FIG. 2 is a diagram for showing the example of the
`channel con?guration employed in the prior-art technique;
`FIG. 3 is a diagram for showing the spectrum signal of
`user information sent at the current information transmission
`rate;
`FIG. 4 is a diagram for showing the spread multiple
`spectrum signal obtained by spread processing the spectrum
`signal;
`FIG. 5 is a diagram for showing the desired wave and
`interference wave spectrum obtained by despread process
`ing the spread multiple spectrum signal;
`
`55
`
`60
`
`65
`
`4
`FIG. 6 is a block diagram for showing the con?guration
`of a ?rst embodiment of the mobile communication unit
`according to the present invention;
`FIG. 7 is a diagram for showing an example of the channel
`con?guration to be employed in the ?rst embodiment;
`FIG. 8 is a block diagram for showing the con?guration
`of a second embodiment of the mobile communication unit
`according to the present invention; and
`FIG. 9 is a diagram for showing an example of the channel
`con?guration to be employed in the second embodiment.
`
`DESCRIPTION OF THE PREFERRED
`EMBODIMENTS
`
`A ?rst embodiment of the present invention will be
`explained with reference to the drawings. FIG. 6 is a block
`diagram for showing the con?guration in one embodiment
`of the present invention. FIG. 7 is a diagram for showing the
`channel structure in this embodiment. In FIG. 6, a symbol 21
`designates a set of units at the transmitter side such as the
`base station and 22 designate units at the mobile station such
`as a car telephone set, a portable telephone set, etc. A symbol
`23 designates a data circuit for transmitting information of
`an information transmission bit rate nB [bps], 24 a separat
`ing circuit for separating information of an information
`transmission bit rate nB [bps] into 11 information of an
`information transmission bit rate B [bps], and 25 and 26
`information input circuits, for inputting user information,
`provided corresponding to channel numbers, each one chan
`nel number allocated to each of users #1, - - -, and #m
`excluding a user #2 in the transmitter side units 21. 27a, '- -
`-, and 27b designate information input circuits provided
`corresponding to channel numbers, n channel numbers allo
`cated to one user (the user #2 in FIG. 7), for inputting
`respective information of n separated information outputted
`from the separating circuit 24. 28, 29, 30a, - - -, and 30b
`designate spread modulators connected to the information
`input circuits 25, 26, 27a, - - -, and 27b respectively, for
`spread processing by using the spread codes corresponding
`to the respective channel numbers. 31 designates a combin
`ing unit for combining spread signals obtained by the spread
`processing, generating a spread multiple spectrum and out
`putting and transmitting this combined signal. In the present
`embodiment, channel numbers #2 to #(1+n) are allocated to
`the user #2 who has the 11 channels.
`The receiver side units 22 are the receiver units including
`portable telephone sets, etc. for the user #2 who has the n
`channels. In the receiver units 22, symbols 32a, - - -, and 32b
`designate n despreaders provided corresponding to the chan
`nels #2 to #(1+n) allocated to the user #2, for performing a
`despread processing in the spread code corresponding to the
`respective channel numbers. 33 designates a multiplexing
`circuit for combining the despreaded information of the n
`channels.
`In the transmitter side units 21, the separating circuit 24
`has the function of separating information of the information
`transmission bit rate nB [bps] into n information of B [bps]
`transmission bit rate as described above. However, it is also
`possible to arrange such that the separating circuit 24 itself
`has a unit for detecting the bit rate of the user information
`inputted from the data circuit 23 and the information sepa
`ration multiple is varied. For example, suppose the user #2
`is allocated with a channel number of n:5 (that is, the
`channel numbers #2, #3, #4, #5 and #6 in FIG. 7), and user
`information of the transmission bit rate 3B [bps] has been
`transmitted to the user #2. In this case, the separating circuit
`
`Page 8 of 12
`
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`24 can detect the 3B [bps] by the transmission bit rate
`detecting unit to separate the user information into three and
`output the separated information by selecting three infor
`mation input circuits out of the ?ve information input
`circuits 27a, - - -, and 27b. With this arrangement, it is
`possible to adapt to various kinds of information transmis
`sion bit rates.
`'
`The spread modulators 28, 29, 30a and 30b are inputted
`with parameters W1(t), W2(t), - - -, and Wm(t) as orthogonal
`spread codes (number of series: m) and a PN(t) as PN series,
`respectively. The orthogonal spread codes are multiplied by
`the PN series to obtain spread codes S1(t), S2(t), - - -, and
`Sm(t) and the spread processing is carried out in these spread
`codes. In the mean time, in the units at the receiver side 22,
`the user of these units is allocated with n channels, so that
`orthogonal spread codes W2(t), - - -, and W1+n(t) corre
`sponding to the channel numbers #2 to #(1+n) are multiplied
`by the PN series to obtain spread code S2(t), - - -, and
`S1+n(t), and a despread processing is carried out by using
`the spread code corresponding to a respective one of these
`channels. FIG. 7 shows a charmel structure for carrying out
`the spread and despread processings.
`The operation of the mobile communication unit having
`the above-described structure will be explained below. In the
`transmitter units 21, user information is inputted from the
`data circuit 23 at the nB [bps] transmission bit rate and user
`information is inputted from the information input circuits
`25 and 26 at the B [bps] transmission bit rate. The user
`information inputted from the data circuit 23 is separated
`into n information by the separating circuit 24 and the 11
`information is outputted from the information input circuits
`27a, - - -, and 27b at the B [bps] transmission bit rate
`respectively. Therefore, at this stage, the transmission bit
`rate of these outputted user information becomes the same as
`the transmission bit rate of the user information inputted
`from the information input circuits 25 and 26. Next, the user
`information inputted from the information input circuits 25,
`26, 27a, - - -, and 27b are inputted to the corresponding
`spread modulators 28, 29, 30a, - - -, and 30b, respectively.
`After these user information have been spread processed by
`the spread modulators 28, 29, 30a, - - -, and 30b, these user
`information are outputted to the combiner 31. The combiner
`31 combines, under the same conditions, the spread signals
`of the plurality of users and the spread signals of the 11
`channels allocated to the user #2, generates a spread multiple
`spectrum and outputs this signal for transmission.
`On the other hand, in the units at the receiver side 22, the
`combined spread signal is received and this signal is
`despread processed by the despreader by using the spread
`code corresponding to a respective one of the channel
`numbers. When one channel number is allocated to the user
`receiver side units, one despreader is used, and when n
`charmel numbers are allocated to the user receiver side units,
`like the user #2, the receiver side units 22 use n despreaders
`from 32a to 32b, as shown in FIG. 6. In the receiver side
`units 22, the received information is despread processed by
`the despreaders 32a, - - -, and 32b so that the received
`information is reproduced by 11 channels at the information
`transmission bit rate B [bps]. The reproduced information is
`inputted to the multiplexing circuit 33, and the 11 channel
`reproduced information are combined by the multiplexing
`circuit 33 to obtain the original user information, and this
`information is outputted from the information output circuit
`34. Thus, the nB [bps] user information has been repro
`duced. By referring to FIGS. 3 to 5, description has already
`been made of the operation status of the changes in the
`waveform when the signal as the user information, that has
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`been transmitted at the B [bps] transmission bit rate, is
`spread processed, transmitted and despreaded. Therefore,
`this explanation will be omitted.
`Through the above-described operation, a high-bit rate
`information transmission service can be provided at the
`information transmission bit rate nB [bps]. Further, the
`structure for transmitting and receiving in the code division
`multiple access at the normal information transmission bit
`rate B [bps] (that is, the information transmission bit rate of
`‘the user to whom only one channel is allocated) can be
`applied straight to the structure of the receiver side units.
`Functions required to be added to the transmitting and
`receiving units for achieving the high-bit rate transmission
`are only the function for separating the nB [bps] information
`into n information of .B [bps] or the function for reverse
`multiplexing the information, which does not involve a
`substantial change of the structure. Further, by only setting
`the n to various values, it is possible to adapt to information
`transmission at various bit rates.
`'
`A second embodiment of the present invention will be
`explained below with reference to the drawings. FIG. 8 is a
`block diagram for showing the con?guration of one embodi
`ment according to the present invention. FIG. 9 is a diagram
`for showing the charmel structure in this embodiment. In
`FIG. 8, a symbol 41 designates a set of units at the
`transmitter side such as the base station or the like, and 42
`designates a set of units at the receiver side such as a mobile
`station, including a car telephone set, a portable telephone
`set, etc. A symbol 43 designates a data circuit for transmit
`ting user information of B [bps] for a high-quality informa
`tion transmission, and 44 designates an error correction
`coding circuit for adding error-correction redundant data to
`the user information to achieve a high-quality information
`transmission and for separating the whole information. 45
`and 46 designate information input circuits provided corre
`sponding to channel numbers, each one charmel number
`allocated to each user #1, - - -, and #m, excluding a user #2
`in the transmitter side units 41, for inputting respective user
`information. 47a, - - -, and 47b designate information input
`circuits provided corresponding to channel numbers allo
`cated by n to one user (the user #2 in FIG. 9), for inputting
`respective n-separated information that have been outputted
`from the error correction coding circuit 44. 48, 49, 50a, - -
`-, and 50b designate spread modulators connected to the
`information input circuits 45, 46, 47a, - - -, and 4712,
`respectively, for carrying out a spread processing by using
`the spread codes corresponding to the respective channel
`numbers. 51 designates a combiner for combining the spread
`signals obtained by the spread processing, generating a
`spread multiple spectrum and outputting and transmitting
`this signal. In the present embodiment, the user #2 having
`the n channels is allocated with channel numbers #2 to
`#(1+n).
`The receiver side units 42 are the units including a
`portable telephone set, etc. for the user #2 having the n
`channels. In the receiver side units 42, symbols 52a, - - -, and
`52b designate n despreaders provided corresponding to the
`channels from #2 to #(1+n) that are allocated to the user #2,
`for carrying out a despread processing in the spread codes
`corresponding to the respective channel numbers. 53 desig
`nates an error correction decoding circuit for carrying out an
`error correction processing after combining the despreaded
`information of 11 channels.
`In the transmitter side units 41, the error correction coding
`circuit 44 adds redundant data of (n-1)B [bps] for error
`correction to the user information of B [bps] that has been
`inputted through the data circuit 43, to generate nB [bps]
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`information, and separates the whole information into n
`information of the information transmission bit rate B [bps].
`In this case, the error correction coding circuit 44 allocates
`the user information out of the whole information of nB
`[bps] to one channel number, separates the redundancy
`component of the error correction coding of (n—l)B [bps] by
`(n-l) and allocates each of the separated redundancy com
`ponents to the remaining (n-l) channel numbers.
`The spread modulators 48, 49, 50a, - - -, and 50b are
`inputted with parameters W1(t), W2(t), - - -, and Wm(t) as
`the respective orthogonal spread codes (number of series: m)
`and a parameter PN(t) as the PN series, respectively. The
`orthogonal spread codes are multiplied by the PN series to
`obtain spread code S1(t), S2(t), - - -, and Sm(t) correspond
`ing to the respective channels, so that a spread processing is
`carried out in these spread codes. On the other hand, in the
`receiver side units 42, the user of these units is allocated with
`the 11 channels, so that orthogonal spread codes W2(t), - - -,
`and W1+n(t) corresponding to the channel numbers from #2
`to #(1+n) are multiplied by the PN series to obtain spread
`codes S2(t), - - -, and S1n(t), to carry out a despread
`processing by using the spread codes-corresponding to these
`channels. FIG. 9 shows a table of the channel structure for
`carrying out these spread and despread processings.
`The operation of the mobile communication unit having
`the above-described structure will be explained below. In the
`transmitter side units 41, user information for a high-quality
`information transmission is inputted from the data circuit 43
`and user information for a normal quality information trans
`mission is inputted from the infonnation circuits 45 and 46.
`The information transmission bit rate for both user infor
`mation is B [bps]. The user information inputted from the
`data circuit 43 is added to redundancy data of (n—1)B [bps]
`for error correction by the error correction coding circuit 44,
`so that information of nB [bps] is generated. The error
`correction coding circuit 44 further separates the whole
`information into n information of the information transmis
`sion bit rate B [bps]. In this case, the error correction coding
`circuit 44 allocates the user information out of the whole
`information of the nB [bps] to one channel number, sepa
`rates the redundancy component of the error correction of
`the (n—1)B [bps] by (n——1) and allocates each of the separated
`redundant components to the remaining (n—1) channel num
`bers.
`The user information inputted from the information input
`circuits 45, 46, 47a, - - -, and 47b or the redundant
`components of the error correction coding are inputted to the
`corresponding spread modulators 48, 49, 50a, - - -, and 5012,
`respectively, and these information or redundant compo
`nents are spread processed by the respective spread modu
`lators 48, 49, 50a, - - -, and 50b, and then outputted to the
`combiner 51. The combiner 51 combines, under the same
`conditions, the spread signals of a plurality of users and the
`spread signals of the n channels allocated to the user #2,
`generates a spread multiple spectrum and outputs and trans
`mits this signal.
`On the other hand, in the receiver side units 42, when the
`combined spread signal