JP3422418B2 - CDMA transmitting circuit and CDMA base station apparatus having the same - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a CDMA (Code Di
vision multiple access) transmission circuit and C having the same
More specifically, the present invention relates to a CDMA transmission circuit that selectively transmits a plurality of user channels to each of a plurality of transmission sequences, and a CDMA base station apparatus including the CDMA transmission circuit.

[0002]

2. Description of the Related Art In a CDMA base station apparatus, a spread spread signal is generated by performing spread processing with different spread codes for each user channel, and a spread spread signal of each user channel is combined and added by an adder. Then
The spread signal that has been combined and added is transmitted by the wireless transmission unit.

[0003]

As the number of spreading circuits increases with an increase in user capacity, the number of adders in the spreading processing section also increases. Therefore, considering the feasibility in hardware, the increase in circuit scale becomes a big problem. Therefore, it is necessary to reduce the number of adders in the spread processing unit and reduce the circuit scale.

The base station device allocates a plurality of frequencies,
Alternatively, a plurality of transmission sequences are provided corresponding to a plurality of antennas, and transmission data is allocated to a plurality of transmission sequences and transmitted. Normally, while transmitting individual transmission data,
The transmission sequence of the transmission data is not switched, but when new transmission data is generated, the communication states such as the number of mobile stations of a plurality of transmission sequences at that time are compared and the new transmission data is transmitted. A sequence is determined, and the new transmission data is transmitted from the determined transmission sequence. In this way, by controlling the number of transmission data from each transmission sequence in a macro manner, the communication quality of each transmission sequence is maintained.

FIG. 2 is a block diagram showing a circuit example of a two-sequence transmission spread processing section used in a conventional transmitter system for a CDMA base station. The diffusion unit 100 includes n diffusers 10.
1 to 10n, a selector unit 110 having an n-series switch with one input and two outputs, a multi-input adder a 120, a multi-input adder b 130, and a selector control unit 140. When the channel transmission data signals having n channels are input to the spreading section 100, the respective signals are input to the respective spreaders 101 to 10n, subjected to spreading processing by different spreading codes, and output as transmission spread signals. . The output spread signal is input to the selector unit 110, the transmission sequence to which the spread signal is output is selected by the control signal from the selector control unit 140, and is output to the multi-input adders 120 and 130 of each sequence. In this case, since the output transmission signal cannot be specified, the multi-input adder 12
The number of inputs of 0 and 130 must be set to n equal to the number of signals to be input in consideration of all cases. As shown in FIG. 4, in a multi-input adder with n inputs, n-1 two-input adders are required. Therefore, in the configuration shown in FIG. 2, there are 2 × (n-1) two-input adders. It becomes necessary to increase the circuit scale. As an example, when the number of channel transmission data inputs is 160 channels, the number of 2-input adders is 2 × (160-1) = 318, which is approximately twice the number of channel transmission data.

According to the present invention, in a CDMA transmission circuit for allocating and transmitting a plurality of transmission data to a plurality of transmission sequences and a CDMA base station apparatus having the same, a CDMA transmission circuit with a reduced adder circuit scale and a CDMA having the same
It is an object to provide a base station device.

[0007]

A CDMA transmission circuit according to the present invention spreads each of a plurality of transmission data with spreading codes different from each other, adds a plurality of signals obtained by the spreading processing, and sums the sums. A plurality of first spreading units that output as a first spread and synthesized signal and a plurality of other transmission data are spread by different spreading codes, and a plurality of signals obtained by the spread processing are added, One or a plurality of second spreading units that output the sum as a second spreading combined signal;
A plurality of first adders for adding the first spread combined signal and the second spread combined signal input from the spreading unit of the above, and a plurality of transmission data, and each of the transmission data is input. A first selector unit for outputting to the first diffusion unit or any one of the second diffusion units, and the one or a plurality of second units
Inputting one or a plurality of the second spread-synthesized signals from the spread section of the second spreading unit and outputting one of the second spread-synthesized signals or each of the second spread-synthesized signals to any one of the first adders. And two selector units.

Further, the CDMA transmission circuit according to the present invention is
In the above CDMA transmission circuit, the number of the plurality of first diffusion units is n (n is a natural number of 2 or more), and the number of the one or plurality of second diffusion units is m (m is a natural number). Yes,
The number of the first adders is n, and the number of inputs of the first adder is (m + 1).

Further, the CDMA transmission circuit according to the present invention is
The above CDMA transmission circuit is characterized by further including a first selector control unit for controlling the first selector unit and a second selector control unit for controlling the second selector unit.

Further, the CDMA transmission circuit according to the present invention is
In the above CDMA transmission circuit, the first spreading section and the second spreading section each include a plurality of spreaders and a second adder.

Further, the CDMA transmission circuit according to the present invention is
The above-mentioned CDMA transmission circuit is further characterized by further including a plurality of transmission radio units for converting the output from each first adder into an analog radio frequency signal.

A CDMA base station apparatus according to the present invention is characterized by including the above CDMA transmission circuit.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The CDMA transmission circuit according to the present invention provides a certain degree of flexibility in the distribution ratio by selectively distributing the digital transmission baseband signal for each specific transmission sequence when there are two or more transmission sequences. By splitting and sharing the spreading unit while maintaining the number, it is possible to reduce the number of inputs of the multi-input adder for combining and adding spread signals in each spreading processing unit. As a result, the number of 2-input adders for configuring the multi-input adder can be reduced, thereby providing a circuit configuration capable of reducing the circuit scale of the diffusion processing unit.

FIG. 1 shows an embodiment of the present invention. The selector unit a 100 selects the input n-series channel transmission data for each specific transmission sequence by the control signal from the selector control unit a 200, distributes the selected n-series channel transmission data to three sequences, and the spreading unit 300.
Output to. The spreading unit 300 is composed of three spreading units: a spreading unit a 310, a spreading unit b 320, and a spreading unit c 330, and the output of the spreading unit a 310 is transmitted to the transmission sequence a.
The output of the spreading unit b 320 is used as the transmission sequence b and the output of the spreading unit c 3
The output of 30 can be output to the transmission sequence a or the transmission sequence b, respectively. Each of the spreading units is provided with the same number of spreaders 311 to 31k as the number of input signals, and the input channel transmission data is spread by different spreading codes for each channel by the spreaders 311 to 31k. The signals are combined and added by the multi-input adder 31n having the same number of outputs as the outputs from the spreaders 311 to 31k and output. The diffusion units 320 and 330 have the same configuration as the diffusion unit 310 and operate in the same manner, but the numbers of diffusers are different from each other, as will be described later. For the output of the shared spreading unit c 330, the transmission sequence is selected by the selector unit 400 that selects the output according to the control signal from the selector control unit b 500, and the 2-input adder a 600 and the 2-input adder b are selected.
700 is input to one of the other diffusion units 310 or 320.
Is combined and added with the diffuse combined signal from. By thus dividing and sharing the spreading unit for a plurality of streams, resources are effectively used and the number of 2-input adders can be reduced.

CDM of CDMA base station apparatus according to the present invention
The configuration of one embodiment of the A transmission circuit is shown in FIG.

Referring to FIG. 3, the CDMA transmission circuit includes a spread processing section 10, a transmission radio section 20, an antenna section 30a, and a 3rd section.
With 0b. The diffusion processing unit 10 has the configuration shown in FIG. 1, and the selector unit a 100 and the selector control unit a 2
00, a spreading section 300, a selector section b 400, a selector control section b 500, a 2-input adder a 600, and a 2-input adder b 700.

The operation of the CDMA transmission circuit when there are two transmission sequences will be described with reference to FIG.

Channel transmission data d1 to d whose number of inputs is n
n is input to the selector unit a 100 in the diffusion processing unit 10. The selector unit a 100 is a selector control unit a
Channel transmission data corresponding to the number of spreaders in the spreading unit is distributed to three sequences for each spreading unit by the control signal from 200, and is output to spreading unit 300. As shown in FIG. 1, spreading section 300 is made up of three spreading sections 310, 320, and 330, and the input three-series transmission data series is input to each spreading section 310, 320, or 330. The channel transmission data input to each spreading unit 310, 320 or 330 is spread by a different spreading code for each channel, and a multi-input adder having the same number of inputs as the outputs of the spreading units 310, 320, 330. It is input to 31n, combined and added there, and output from there. Shared diffusion part c 3
The output of 30 is selected as a transmission sequence in a selector unit b 400 that selects an output according to a control signal from a selector control unit b 500, and is input to one of a 2-input adder a 600 and a 2-input adder b 700 and spread to the other. It is combined and added with the spread combined signal from the unit 310 or 320. Therefore,
The spread processing unit 10 outputs the two series of digital combined spread signals to the transmission wireless unit a 20a and the transmission wireless unit b 20b, respectively. Transmission wireless unit a 20a, transmission wireless unit b 20
b is the amplitude limit of the input digital composite spread signal,
Spectrum shaping, quadrature modulation, frequency conversion, D / A conversion,
Transmission power control is performed, and the results are output to the antennas 30a and 30b as analog radio frequency signals.
The antennas 30a and 30b radiate and output the input radio frequency signal.

Next, the detailed structure of the multi-input adder shown in FIG. 1 will be described.

FIG. 4 is a block diagram of an n-input adder having n inputs. The n-input adder is n-1 2-input adder 1
.About.n-1. Each adder calculates the final composite addition of the input n by adding the two sets of input data and outputting it to the input of the next adder. The number of bits of input data of the adder is, for example, 24 bits.

In FIG. 3, an example will be described in which the number of input channel transmission data is 160 channels, 128 channels or 80 channels are output to the transmission sequence a, and 32 channels or 80 channels are output to the transmission sequence b. Figure 1
As shown in FIG. 5A, the number of diffusers in each diffusion unit is 80 for the diffusion unit a 310, 32 for the diffusion unit b 320, and 48 for the diffusion unit c 330. Distribute the vessel. In the case of "transmission sequence a-128 channels / transmission sequence b-32 channels", FIG.
As shown in (b), the diffusion part a 310 and the diffusion part c 3
30 are combined and added to form a transmission sequence a 3aa and a transmission sequence b.
Make up 3ab. On the other hand, in the case of "transmission sequence a-80 channel / transmission sequence b-80 channel", FIG.
As shown in, the spreading unit b 320 and the spreading unit c 330 are combined and added to form a transmission sequence a 3ba and a transmission sequence b 3b.
b.

The selector section a 100 shown in FIG. 1 is controlled by the selector control section a 200 to input the channel transmission data into 80 channels, 32 channels and 48 channels.
Channel, and each of the diffusion units 310, 320,
Output to 330. The diffusers 310, 320, 330 are
Spreading processing is performed on the input channel transmission data with mutually different spreading codes.

After the spreading process, the 80-input adder of the spreading unit a 310 synthesizes and adds the spread signals of 80 channels,
The combined and added signal is output to the 2-input adder a 600. Similarly, the 32-input adder of the transmitter b 320 is
The spread signals for two channels are combined and added, and the combined and added signal is output to the 2-input adder b 700. The 48-input adder of the spreading unit c combines and adds the spread signals of 48 channels and outputs the combined and added signal to the selector unit b 400.

The selector section b 400 receives the "transmission sequence a-12" according to the control signal from the selector control section b 500.
8 channels / transmission sequence b2-32 channels ", 2
The combined spread signal is output to the input adder a 600, and “transmission sequence a-80 channels / transmission sequence b2-80 channels”
In the case of, the combined spread signal is output to the 2-input adder b 700.

In the case of "transmission sequence a-128 channels / transmission sequence b-32 channels", 2-input adder a 600
Is a combined diffused signal for 80 channels from the spreader a 310 and a combined diffused signal for 48 channels from the spreader c 330, and the 2-input adder b 700 is 32 channels from the spreader b 320. By outputting only the composite spread signal of the minute, a transmission signal of 128 channels to the transmission sequence a and a transmission signal of 32 channels to the transmission sequence b are output.

"Transmission sequence a-80 channels / transmission sequence b"
In the case of “-80 channels”, the 2-input adder b 700 is
The combined spread signal of 32 channels from the spreader b 320 and the combined spread signal of 48 channels from the transmitter c 330 are combined and added, and the 2-input adder a 600 determines that the spreader a 600
By outputting only the composite spread signal for 80 channels from 310, the transmission signals of 80 channels are transmitted to the transmission sequence a and the transmission signals of 80 channels are transmitted to the transmission sequence b.

In this case, the number of two-input adders of the spreader a 310 is 80-1 = 79, the number of two-input adders of the spreader b320 is 32-1 = 31, and the number of two-input adder of the spreader c 330 is two. The number is 48-1 = 47, and the number of 2-input adders in the spread processing unit 10 in FIG. 3 is 79 + 31 + 47 + 2 =
There will be 159. On the other hand, in the conventional spread processing unit, the multi-input adder a 120 requires 159 two-input adders, and the multi-input adder b130 also requires 159 two-input adders, so that a total of 318 2 2-input adders are required. Therefore, according to this embodiment, the number of adders can be reduced to about half as compared with the conventional spread processing unit.

Next, another embodiment of the present invention will be described with reference to FIG.

Referring to FIG. 6, the diffusion processing section includes a selector section a 100 and a selector section a 100 for distributing inputs.
A selector control unit b 200 for controlling the transmission sequence, a spreading unit a 310 for transmitting the spread and synthesized signal to the transmission sequence a, a transmission unit b 320 for transmitting the spread and synthesized signal to the transmission sequence b, and a transmission sequence a.
And a plurality of spreading units m 330B and spreading units m 300B capable of transmitting the spreading combined signal to both the transmission sequence b and the multi-input (four-input) adder a 60.
0B or a multi-input (four-input) adder b 700B, a selector b 400B for outputting to the adder b 700B, a selector controller 500B for controlling the selector b 400B, a spread combined signal from the spreader a 310, and 1 to 3 from the selector b. A multi-input (4-input) adder a for combining and adding the individual spread combined signals
A multi-input (four-input) adder b 700b for combining and adding the spread combined signal from the spreader b 320 and one to three spread combined signals from the selector b is provided. A plurality of diffusion units can be provided by reducing the number of diffusers in each diffusion unit.

This embodiment has a new effect that the distribution of the number of channel transmission data can be set in more detail by subdividing the shared spreading section. For example, by distributing the 48 spreaders included in the spreading unit c 330 of FIG. 1 to the three spreading units m 330B by 16 units each, “transmission sequence a-128 channels / transmission sequence b-32 channels”, “transmission sequence a-128 channels” Sequence a-112 channel / transmission sequence b-4
8 channels "," transmission sequence a-96 channels / transmission sequence b-64 channels ", and" transmission sequence a-80 channels / transmission sequence b-80 channels "can be realized.

Still another embodiment will be described with reference to FIG. Compared with the embodiment shown in FIG. 6, this embodiment shown in FIG. 7 expands the number of spreaders that transmit spread combined signals to a specific transmission sequence from two to n, and expands two multi-inputs (4 Input) n multi-input adders ((m + 1) input)
Replaced by an adder, and replaced the selector section b 400a of 3 inputs and 6 outputs (1 input and 2 outputs of 3 systems) with the selector section b 400C of m inputs and mn outputs (1 input and n outputs of m series) and spread to the selector section b. 3 spreaders that output the combined signal
The difference is that the number is expanded from m to m. This embodiment has a new effect that the transmission sequence can be increased and the distribution of the number of transmission channel data can be set more finely.

Normally, the control signal output from the selector control unit b for controlling the selector unit b is CDMA.
When installing the base station device, set it to a certain value according to the installation location and do not change it during operation. On the other hand, similarly to the control signal output by the selector control unit 140, the control signal output by the selector control unit a for controlling the selector unit a is newly generated transmission data according to the communication state of each transmission sequence. It is set for each.

Although only the CDMA transmission circuit is shown in FIG. 3, the CDMA base station apparatus receives the analog radio frequency signals received from a plurality of mobile stations by frequency conversion, quadrature demodulation, and the like. A despreading processing unit that demodulates the data of each channel by despreading the output from the radio unit and the reception radio unit, a communication unit that communicates with other CDMA base station devices, and the like.

[0034]

The first effect is that the number of 2-input adders can be reduced while maintaining a certain degree of flexibility in the distribution ratio to the transmission sequence, so that the circuit scale by hardware can be reduced. is there.

The reason is that channel transmission data having different transmission sequences are distributed at a specific ratio to share a spreading unit for a plurality of sequences, so that effective use of resources can be achieved, and post-spreading synthetic addition is performed. This is because the number of inputs of the multi-input adder can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a spreading processing unit of a CDMA transmission circuit according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a spreading processing unit of a CDMA transmission circuit according to a conventional example.

FIG. 3 is a block diagram showing a configuration of a CDMA transmission circuit.

FIG. 4 is a circuit diagram showing a configuration of an n-input adder.

FIG. 5 is a diagram for explaining channel number allocation in the spreading processing unit of the CDMA transmission circuit according to the embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration of a spreading processing unit of a CDMA transmission circuit according to another embodiment of the present invention.

FIG. 7 is a block diagram showing a configuration of a spreading processing unit of a CDMA transmission circuit according to still another embodiment of the present invention.

[Explanation of symbols]

100 selector part a 200 selector control unit a 300 diffusion unit 400 selector part b 500 selector control unit b 600 2-input adder a 700 2-input adder b 311 to 31k diffuser 31n multi-input adder

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields investigated (Int.Cl. ⁷ , DB name) H04J 13/00-13/06 H04B 1/69-1/713

Claims (6)

(57) [Claims] 1. A plurality of first spreading signals, each of which is spread by different spreading codes from each other, adds a plurality of signals obtained by the spreading process, and outputs the sum as a first spread and synthesized signal. One spreading section and each of a plurality of other transmission data are spread with mutually different spreading codes, a plurality of signals obtained by the spreading processing are added, and the sum is output as a second spread combined signal. One or a plurality of second spreaders, a plurality of first adders that add the first spread combined signal input from each first spreader and the second spread combined signal input, And a second selector which outputs each transmission data to any one of the first spreading units or one of the second spreading units, and the one or more second spreading units. Input one or more of the second spread combined signals from CDMA transmission circuit, characterized in that it comprises a second selector unit for outputting a second spread composite signal or each second diffusion composite signal to one of said first adder, a. 2. The CDMA transmission circuit according to claim 1, wherein the number of the plurality of first spreading units is n (n is a natural number of 2 or more), and the number of the one or plurality of second spreading units is A CDMA transmission circuit, wherein the number is m (m is a natural number), the number of the first adder is n, and the number of inputs of the first adder is (m + 1). 3. The CDMA transmission circuit according to claim 1, wherein the first selector control unit controls the first selector unit, and the second selector control unit controls the second selector unit. And a CDMA transmission circuit further comprising: 4. The CDMA transmission circuit according to claim 1, wherein the first spreading unit and the second spreading unit include a plurality of spreaders and a second adder. A CDMA transmission circuit characterized by the above. 5. The CDMA transmission circuit according to claim 1, further comprising a plurality of transmission radio units that convert an output from each first adder into an analog radio frequency signal. And a CDMA transmission circuit. 6. A CDMA base station device comprising the CDMA transmission circuit according to claim 1. Description: