JP2010213358A - Device and method for multiplexing control channel, and radio communication equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain an efficient control channel by preventing or reducing demerits such as assigned notification (which can be changed), a division loss, a large dynamic range of transmission power, giving interference variation in conventional techniques. <P>SOLUTION: This device is provided with: a code spreading means which code-spreads two or more control channels assigned to each mobile station using orthogonal codes in the case of multiplexing the two or more control channels assigned to each mobile station on a frequency axis; and a multiplexing means which multiplexes a subcarrier signal obtained by code spreading on the frequency axis. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a control channel multiplexing apparatus, a control channel multiplexing method, and a radio communication apparatus.

  In a mobile communication system, a control channel for transmitting control information is an indispensable channel for controlling all mobile stations so that they can communicate at any time, and always requires high reception quality. On the other hand, the signal reception strength varies greatly depending on the distance between the mobile station and the base station. For example, a difference of about 60 dB may occur in a general cellular system.

  When the same control channel is used, a control channel that matches the mobile station having the worst reception state is required, and the use efficiency of the radio channel deteriorates. Therefore, it has been studied to prepare a plurality of types of control channels according to the reception state of the mobile station and to efficiently use the radio channel.

As a first method, a plurality of control channels having different required Eb / No (energy-to-noise power density ratio per bit in a digital modulation signal) are prepared, and different control channels are used according to the reception state of the mobile station. Are known. However, this method has disadvantages such as allocation notification (changed) and division loss.
As a second method, it is known to control transmission power of a control channel for each mobile station (see, for example, Patent Document 1). However, this method requires a wide dynamic range and has the demerits that the interference power to other sectors or other cells fluctuates.

JP 2000-244970 A

  As described above, the conventional techniques have disadvantages such as allocation notification (changed), division loss, a large dynamic range of transmission power, and fluctuations in interference, which makes it difficult to realize an efficient control channel. is there.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a control channel multiplexing apparatus and a control channel multiplexing method capable of realizing an efficient control channel.

  In order to solve the above problems, a control channel multiplexing apparatus according to the present invention is a control channel multiplexing apparatus that multiplexes a plurality of control channels assigned to each mobile station, and uses the orthogonal codes for the plurality of control channels. Code spreading multiplexing means for code spreading multiplexing, inverse Fourier transform means for converting frequency domain signals obtained by the code spreading multiplexing into time domain signals as continuous subcarriers, and depending on the reception state of the mobile station, And a spread code creating means for creating a code-multiplex-only spread code or a spread code combining code-multiplexing and frequency-multiplexing from orthogonal codes.

In the control channel multiplexing apparatus according to the present invention, the orthogonal code is a Walsh-Hadamard code or a rotation orthogonal code.
A radio communication apparatus according to the present invention includes the control channel multiplexing apparatus described above.

  A control channel multiplexing method according to the present invention is a control channel multiplexing method for multiplexing a plurality of control channels assigned to each mobile station, wherein the plurality of control channels are code spread multiplexed using orthogonal codes; Depending on the process of inverse Fourier transforming the frequency domain signal obtained by the code spreading multiplexing into a time domain signal as a continuous subcarrier and the reception state of the mobile station, the code multiplexing single type spreading code or code And a step of creating a spread code using both multiplexing and frequency multiplexing from orthogonal codes.

  According to the present invention, it is possible to prevent or reduce the disadvantages of the prior art and realize an efficient control channel.

It is a figure which shows an example of the mobile communication system used in order to demonstrate embodiment of this invention. It is explanatory drawing used in order to demonstrate the prior art by AMC. It is explanatory drawing used in order to demonstrate the prior art by TPC. It is explanatory drawing used in order to demonstrate the prior art by TPC. It is a figure which shows the relationship between the power density and frequency of control channels CA1-CA3 which concern on 1st Embodiment of this invention. It is a block diagram which shows the transmission structure of the radio | wireless communication apparatus which concerns on 1st Embodiment of this invention. It is a flowchart which shows the procedure of the control channel multiplexing method which concerns on 1st Embodiment of this invention. It is a block diagram which shows the transmission structure of the radio | wireless communication apparatus which concerns on 2nd Embodiment of this invention. It is a flowchart which shows the procedure of the control channel multiplexing method which concerns on 2nd Embodiment of this invention. It is a figure which shows the relationship between the power density and frequency of control channel CA1-CA4 which concerns on 2nd Embodiment of this invention. It is a figure which shows an example of the several L1 / L2 control information stream multiplexing system based on FDM (or TDM). It is a figure which shows an example of the some L1 / L2 control information stream multiplexing system of a CDM base. It is a figure which shows an example of allocation of a different MCS based on the path loss information from UE. It is a figure which shows the mapping method of the MCS area | region of Localized mapping of an MCS block. It is a figure which shows the mapping method of the MCS area | region of Distributed mapping of an MCS block. It is a figure which shows the application method of block interleaving after spreading | diffusion. FIG. 3 is a block diagram of a circuit that realizes adaptive phase rotation angle control of a CDM-based L1 / L2 control information stream. It is a figure which shows an example of the proposal OVSF code allocation by each MCS for a TDM based control channel structure. It is a figure which shows an example of the OVSF code assignment proposed by each MCS for FDM-based control channel configuration. FIG. 5 is a block diagram of a circuit that realizes adaptive phase rotation angle control due to a difference in spreading factor of a CDM-based L1 / L2 control information stream.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First, the point of focus according to the present invention will be outlined.
FIG. 1 is a diagram illustrating an example of a cellular system as a mobile communication system. In FIG. 1, base stations A and B are adjacent base stations. The mobile stations A1 to A3 are mobile stations under the base station A. The mobile stations B1 to B3 are mobile stations under the base station B. Here, it is assumed that the mobile stations A1, A2 and A3 are close to the base station A in the order and the reception state is good, and the mobile stations B1, B2 and B3 are close to the base station B and the reception state is good.

  According to the conventional technology based on AMC (Adaptive Modulation and Coding), the control channels assigned to the mobile stations A1 to A3 are as shown in FIG. FIG. 2 shows the relationship between power density and frequency. Here, since the control channel CA1 assigned to the mobile station A1 in a good reception state achieves a desired quality with a small number of radio resources, the occupied frequency bandwidth is narrow. On the contrary, the control channel CA3 assigned to the mobile station A3 having a poor reception state occupies a wide frequency band.

  As described above, in the conventional technique using the AMC, it is necessary to change the frequency bandwidth occupied by the control channel according to the reception state of the allocation-destination mobile station so that the mobile station can always receive the control channel. Therefore, a mechanism for updating the allocation information as needed and notifying the mobile station is required. Further, since the occupied frequency bandwidth differs depending on the control channel, the allocation process becomes complicated when a large number of control channels are allocated. Alternatively, there is a method of determining the frequency band to be allocated in advance for each MCS (Modulation and Coding Set) set and allocating efficiently, but in this case, division loss may occur.

  According to the prior art based on TPC (Transmission Power Control), the control channel assigned to each mobile station is the same type (the same MCS set), but the transmission power is controlled according to the reception state of each mobile station. That is, as in the relationship between power density and frequency shown in FIG. 3, the control channel CA1 assigned to the mobile station A1 in a good reception state transmits with a small amount of power. Conversely, a large amount of transmission power is used for the control channel CA3 allocated to the mobile station A3 having a poor reception state. The problems of the prior art using this TPC are that the interference varies and a large dynamic range of transmission power is required.

  FIG. 4 shows the relationship between power density and frequency by TPC related to the control channel assigned to mobile stations B1 to B3. Since the control channels used in adjacent base stations are generally the same frequency band, FIGS. 3 and 4 are the same frequency band. That is, the control channels transmitted by base station A and base station B are interference with each other. It means to become. For example, the transmission power of the control channel CA3 assigned to the mobile station A3 at a certain point in time may be insufficient or excessive depending on the transmission power of the control channel CB3 at the next moment. Therefore, changing the transmission power of the control channel may not operate smoothly when viewed in the entire system.

  Based on the above-described knowledge, in the present invention, when a plurality of control channels assigned to each mobile station are multiplexed on the frequency axis, the plurality of control channels assigned to each mobile station are frequency-converted using orthogonal codes. Code-multiplex in the direction. Hereinafter, each embodiment will be described in detail.

[First Embodiment]
In the first embodiment, a complex orthogonal code is used.
FIG. 5 is a diagram showing a relationship between power density and frequency of the control channels CA1 to CA3 of the mobile stations A1 to A3 of FIG. 1 according to the first embodiment of the present invention. Here, a code is multiplexed in the frequency direction using a complex orthogonal code having a code length of 3.

FIG. 6 is a block diagram showing a transmission configuration of the wireless communication apparatus according to the first embodiment of the present invention. Note that the wireless communication apparatus shown in FIG. 6 is of the Orthogonal Frequency Division Multiplexing (OFDM) system.
In FIG. 6, the control information of the control channel CAn is error correction encoded by the error correction encoding unit 10 and then converted into a modulation symbol SAn by the modulator 11. The power control unit 12 controls the transmission power of the modulation symbol SAn according to the reception state of the mobile station. Thereby, the transmission power given to the control channel is controlled according to the reception state of the mobile station.

  The code spreading unit 13 code spreads the modulation symbol SAn using a predetermined complex orthogonal code. The subcarrier signal Fm obtained by code spreading is subjected to inverse fast Fourier transform processing by an inverse fast Fourier transform unit (IFFT) 14 and converted from a frequency domain signal to a time domain signal. As a result, an OFDM signal in which the subcarrier signals obtained by code spreading are multiplexed on the frequency axis is obtained. In this OFDM signal, control information of the control channel CAn is code-multiplexed in the frequency direction using a complex orthogonal code.

Here, the operation of this embodiment will be described with a specific example shown in FIG.
The modulation symbols corresponding to the control channels CA1 to CA3 of the mobile stations A1 to A3 shown in FIG. Further, subcarriers when transmitting control information by the OFDM method are F1 to F3. If the transmission powers of the control channels CA1 to CA3 are GA1 to GA3, respectively, the subcarriers F1 to F3 are given by the following equation [Equation 1] using a 3 × 3 complex orthogonal code matrix, for example.

  Here, in the present embodiment, by performing control channel multiplexing (Multi Carrier-Code Division Multiplexing: CDM) using complex orthogonal codes, the transmission powers of the subcarriers F1 to F3 are equal as shown in FIG. Further, even if the reception state of a certain mobile station, for example, the mobile station A1, changes and the transmission power GA1 needs to be increased, the power increment per frequency is the same as the conventional frequency division multiplexing (Frequency Division). Compared with Multiplexing (FDM), 1/3 is sufficient. Furthermore, the transmission power of the other control channels CA2 and CA3 multiplexed on the same subcarrier as that control channel CA1 is likely to change in a direction where it can be reduced on average. That is, if all the changes in the reception states of the mobile stations A1 to A3 are averaged, it is expected to be zero, so that the power of each of the subcarriers F1 to F3 can be expected to hardly change.

  As described above, according to the present embodiment, by performing control channel multiplexing (CDM) using complex orthogonal codes, the interference characteristic due to transmission power control is smoother than conventional multiplexing (FDM) for each subcarrier. The effect of making is obtained. That is, according to the present embodiment, it is possible to solve the interference problem that was a problem in TPC when the control channels are multiplexed by the FDM method. Thereby, it becomes possible to guarantee the stable operation of the entire mobile communication system.

  In the above-described embodiment, the code length is described as 3. However, any code length can be used, and the same effect can be obtained.

  FIG. 7 shows the procedure of the control channel multiplexing method according to the first embodiment of the present invention. In FIG. 7, first, in step S10, the control information of the control channel is error correction encoded. In step S11, the encoded signal is converted into a modulation symbol. In step S12, the modulation symbol transmission power is controlled according to the reception state of the mobile station. In step S13, the modulation symbols are code-spread using a predetermined complex orthogonal code. In step S14, the subcarrier signal obtained by code spreading is frequency-multiplexed by inverse fast Fourier transform. Thereby, the control information of the control channel is code-multiplexed in the frequency direction using the complex orthogonal code.

[Second Embodiment]
In the second embodiment, Walsh-Hadamard codes are used. Then, OVSF (Orthogonal Variable Spreading Factor) allocation using Walsh-Hadamard codes is performed. The assignment notification is necessary.

  FIG. 8 is a block diagram showing a transmission configuration of the wireless communication apparatus according to the second embodiment of the present invention. The wireless communication apparatus shown in FIG. 8 is of the OFDM system as in FIG. In FIG. 8, parts corresponding to those in FIG. 6 are given the same reference numerals, and explanation thereof is omitted. FIG. 9 shows the procedure of the control channel multiplexing method according to the second embodiment of the present invention. 9, parts corresponding to the respective steps in FIG. 7 are denoted by the same reference numerals and description thereof is omitted.

In the wireless communication apparatus shown in FIG. 8, a spread code creating unit 21 is provided. The spreading code creating unit 21 creates a spreading code for performing OVSF allocation. The spreading code creating unit 21 creates a spreading code with a processing gain according to the reception state of the mobile station from the Walsh-Hadamard code. The processing gain corresponds to the code length (spreading rate).
In the control channel multiplexing method shown in FIG. 9, step S21 for creating a spreading code is provided. Step S21 is a step of creating a spreading code for performing OVSF assignment. In step S21, a spreading code having a processing gain corresponding to the reception state of the mobile station is created from the Walsh-Hadamard code.

Here, the operation of this embodiment will be described with a specific example.
As mobile stations under the base station A shown in FIG. 1, there are mobile stations A1 to A4 (the mobile station A4 is not shown), and modulation symbols corresponding to the control channels CA1 to CA4 of the mobile stations A1 to A4 are SA1 to SA4. And Here, it is assumed that the reception states of the mobile stations A1 and A2 are good and the reception states of the mobile stations A3 and A4 are bad. In this case, a spreading code (0, 1) is created for the control channels CA1 and CA2 of the mobile stations A1 and A2. Furthermore, frequency multiplexing is used together for these control channels CA1 and CA2. On the other hand, a spreading code (0, 0, 1, 1) is created for the control channel CA3 of the mobile station A3, and a spreading code (0, 0, 0, 0) is created for the control channel CA4 of the mobile station A4. Create Then, code multiplexing is performed for each of the control channels CA3 and CA4. That is, the spreading code creating unit 21 creates a code-multiplexed single spreading code or a code-spreading and frequency-multiplexing spreading code from the Walsh-Hadamard code according to the reception state of the mobile station.

  Here, when subcarriers when transmitting control information by the OFDM method are F1 to F4, and transmission powers of the control channels CA1 to CA4 are GA1 to GA4, respectively, the subcarriers F1 to F4 are expressed by the following equation [Equation 2]. Given in.

FIG. 10 shows the relationship between power density and frequency of the control channels CA1 to CA4. Here, a Walsh-Hadamard code having a code length of 4 and a Walsh-Hadamard code having a code length of 2 are combined so as to maintain an orthogonal relationship. That is, the spread code creation unit 21 creates spread codes having different processing gains so as to maintain an orthogonal relationship.
What should be noted here is that the processing gains of the control channels CA1 and CA2 and the control channels CA3 and CA4 are twice different. For example, when the reception states of the mobile stations A1, A2 and the mobile stations A3, A4 differ by a factor of four, it is optimal to set the ratio of the transmission powers GA1, GA2 and the transmission powers GA3, GA4 to a factor of four. However, in this embodiment, the processing gains (code lengths) of the control channels CA1 and CA2 and the control channels CA3 and CA4 are twice different, so that the transmission powers GA1 and GA2 and the transmission powers GA3 and GA4 are the remaining twice. Make a difference. That is, the dynamic range of transmission power can be reduced.

  As described above, according to the present embodiment, the dynamic range in the TPC can be reduced by partially using the spreading code.

  In the above-described embodiment, the case where the code length is used in a combination of 2 and 4 has been described. However, any combination of code lengths that can be expressed by a power of 2 can be used, and the same effect can be obtained.

[Third Embodiment]
In the third embodiment, a rotation orthogonal code is used. The transmission configuration of the wireless communication apparatus according to the third embodiment is the same as that in FIG. The control channel multiplexing method according to the third embodiment is the same as that shown in FIG. However, the third embodiment is different in that a spread code is created using a rotation orthogonal code.

  When the control channel is code-multiplexed on the frequency axis, intersymbol interference occurs due to frequency selectivity at the time of reception in the mobile station. In particular, when the code length is large, intersymbol interference becomes significant. In the present embodiment, in order to solve the problem of intersymbol interference, control channels are multiplexed using a rotating orthogonal code.

Here, the operation of this embodiment will be described with a specific example.
As mobile stations under the base station A shown in FIG. 1, there are mobile stations A1 to A4 (the mobile station A4 is not shown), and modulation symbols corresponding to the control channels CA1 to CA4 of the mobile stations A1 to A4 are SA1 to SA4. And Here, it is assumed that the reception states of the mobile stations A1 and A2 are good and the reception states of the mobile stations A3 and A4 are bad. In addition, the code length for code-multiplexing the control channels CA1 to CA4 is 4. In this case, if the rotation angles are θ1 and θ2, a rotation orthogonal matrix R4 having a code length of 4 is given by the following equation [Formula 3].

  A spreading code given by the first row vector in the rotation orthogonal matrix R4 is created as a spreading code for the control channel CA3. Also, a spreading code given by the third row vector in the rotation orthogonal matrix R4 is created as a spreading code for the control channel CA4. On the other hand, the spreading code in the second row in the rotation orthogonal matrix R2 is used for the control channels CA1 and CA2. Furthermore, frequency multiplexing is used together for these control channels CA1 and CA2. That is, the spread code creating unit 21 creates a code-multiplex-only spread code or a spread code using both code-multiplex and frequency-multiplex from the rotation orthogonal matrix according to the reception state of the mobile station.

  Here, when subcarriers when transmitting control information by the OFDM method are F1 to F4 and the transmission powers of the control channels CA1 to CA4 are GA1 to GA4, respectively, the subcarriers F1 to F4 are expressed by the following equation [Equation 4]. Given in.

  On the receiving side, control channel CA1 is obtained by despreading subcarriers (F1, F2) using spreading codes (-sin θ1, cos θ1). The control channel CA2 is obtained by despreading the subcarriers (F3, F4) using the same spreading code (-sinθ1, cosθ1). The control channel CA3 is obtained by despreading the subcarriers (F1, F2, F3, F4) using the spreading code (cosθ1cosθ2, sinθ1cosθ2, cosθ1sinθ2, sinθ1sinθ2).

  The feature point of this embodiment is that an intermediate property between frequency multiplexing and Walsh-Hadamard code multiplexing can be obtained by code multiplexing using a rotation orthogonal code. In [Equation 4], if “θ1 = θ2”, the control channel CA1 is the subcarrier F2, the control channel CA2 is the subcarrier F4, the control channel CA3 is the subcarrier F1, and the control channel CA4 is the subcarrier F3. The frequency multiplexing is assigned to each. On the other hand, if “θ1 = θ2 = π / 4 (radian)”, this is equivalent to Walsh-Hadamard code multiplexing. Therefore, by setting the rotation angles θ1 and θ2 to appropriate values, fluctuations in the interference characteristics, which are disadvantages of frequency multiplexing, and intersymbol interference, which is a disadvantage of Walsh-Hadamard code multiplexing, fall within an appropriate range. Is possible.

  As described above, according to the present embodiment, by performing code multiplexing using a rotation orthogonal code, it is possible to adjust and use the properties of both frequency multiplexing and Walsh-Hadamard code multiplexing.

The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes design changes and the like within a scope not departing from the gist of the present invention.
In each of the embodiments described above, the transmission configuration of the wireless communication apparatus has been described. However, the reception configuration may correspond to the transmission configuration.

The technical contents on which the present embodiment is based will be described below. This is a description of CDM-based multiple L1 / L2 control channel multiplexing schemes and related technologies.
[Proposal of L1 / L2 control channel configuration]
[Multiple L1 / L2 control information stream multiplexing based on CDM]
Based on the effective features of CDM, we propose a CDM-based multiple L1 / L2 control information stream multiplexing scheme as shown in Figure 12. However, in CDM-based multiplexing of multiple L1 / L2 control information streams, inter-code interference due to frequency selective fading degrades the packet error rate (PER) characteristics. Therefore, Rotation-CDM is applied to multiple L1 / L2 control information stream multiplexing.

[Application of combined TPC and AMC for L1 / L2 control information bits]
In a multipath fading environment, good radio conditions must be achieved to satisfy the required PER in the L1 / L2 control information bits of all cells. Currently, two types of Link Adaptation methods have been proposed for L1 / L2 control information bits: TCP and adaptive modulation / demodulation and channel coding (AMC). Therefore, a method that combines TPC and AMC is applied to the L1 / L2 control information bits.

[Assignment of each MCS for different path loss areas]
The modulation / demodulation method and coding method (MCS) that can be used by AMC are limited by the limitation of the number of control signal bits. Therefore, at most several sets of MCS are used. Next, the area of all cells is divided into several areas based on rough path loss values as shown in Figs. L1 / L2 control information bits are transmitted using different MCSs according to the divided service areas. In practice, the MCS for each UE is assigned based on the path loss information from the UE. In the same MCS region, multiple L1 / L2 control channels for each UE are multiplexed by CDM. Also consider two types of MCS mapping methods, Localized mapping and Distributed mapping of MCS blocks shown in Figs. AMC works more accurately with localized MCS block mapping following instantaneous changes in the frequency domain than with distributed MCS block mapping. However, greater frequency diversity effects can be obtained with Distributed MCS block mapping.

[Use of TPC for compensation of instantaneous fading]
TPC is applied to the L1 / L2 control information bits to compensate for instantaneous fading fluctuations. By using TPC and AMC in combination, the dynamic range of TPC is reduced compared to using TPC alone. We use CQI-based TPC suitable for packet-based signals.

[Technology to achieve good radio conditions for CDM-based L1 / L2 control channels]
Two techniques for CDM-based L1 / L2 control channel multiplexing to achieve good radio conditions are described below.
[Block interleaving after spreading]
When CDM-based multiplexing is performed, the encoded information symbols in the TDM-based L1 / L2 control channel configuration are spread to the frequency domain. In general, inter-code interference occurs when the orthogonality of the code area is lost in frequency selective fading. Therefore, as shown in Figure 16, block interleaving is applied after spreading to keep the inter-code interference at a low level. Also, in an FDM-based L1 / L2 control channel configuration, block interleaving after spreading is effective in suppressing inter-code interference due to channel fluctuations in the time domain (Figure 16).

[Adaptive phase angle control (rotational-CDM)]
We propose Rotational-CDM to reduce inter-code interference in CDM-based physical channels. Inter-code interference is a trade-off relationship with the averaging effect of received level fluctuation over the spread code length, that is, the frequency (time) diversity effect. Therefore, the best PER characteristics can be obtained from the trade-off relationship between suppression of inter-code interference and frequency (time) diversity effect. In this method, the optimum PER characteristics are obtained by adaptively controlling the phase rotation angle of the multiplexed code channel according to the degree of frequency (time) selectivity. Therefore, as shown in Figure 17, we propose adaptive phase rotation angle control of multiple L1 / L2 control information streams including block interleave after spreading. By using a combination of block interleave after spreading and adaptive phase rotation angle control, the inter-code interference is suppressed to a slight level while obtaining a certain degree of frequency (time) diversity effect. Adaptive phase rotation applies to both TDM and FDM-based multiplexing configurations of L1 / L2 control information including shared data channels where frequency spread and time selectivity due to delay spread and Doppler are issues.

[Application of OVSF code in CDM-based L1 / L2 control channel multiplexing]
As explained, in order to support a wide service area, in addition to TPC, AMC with limited types of MCS is applied. However, the number of UEs in each MCS region based on path loss is not uniformly distributed. Therefore, frequency resources are allocated to each MCS region in advance, so the number of simultaneous L1 / L2 control channels in each MCS region is also uneven. As a result, the frequency utilization efficiency of the L1 / L2 control channel decreases. Therefore, we propose orthogonal variable spreading factor (OVSF) code assignment in the MCS domain for CDM-based L1 / L2 control channel multiplexing. Figures 18 and 19 show the proposed OVSF code assignment by each MCS for TDM or FDM based control channel configuration. From the figure, frequency resources can be effectively used even when multiple MCSs are generally used by applying OVSF codes. In addition, as shown in Fig. 20, the phase rotation is adaptively controlled by the difference in spreading factor.

[Conclusion]
The above describes multiple CDM-based multiple L1 / L2 control information stream multiplexing for each UE. The following technologies were described for CDM-based L1 / L2 control information stream multiplexing.
Application of adaptive phase rotation in CDM-based L1 / L2 control information stream to achieve optimal PER by trade-off between inter-code interference suppression and frequency (time) diversity gain acquisition MCS limited Application of TPC and AMC combination method in number ・ Application of OVSF code to each MCS so that frequency resources are generally effectively used in multiple MCS

DESCRIPTION OF SYMBOLS 10 ... Error correction encoding part, 11 ... Modulator, 12 ... Power control part, 13 ... Code spreading | diffusion part, 14 ... Inverse fast Fourier-transform part (IFFT)

Claims (4)

In a control channel multiplexer that multiplexes a plurality of control channels assigned to each mobile station,
Code spreading multiplexing means for code spreading multiplexing the plurality of control channels using orthogonal codes;
An inverse Fourier transform means for transforming a frequency domain signal obtained by the code spread multiplexing into a time domain signal as a continuous subcarrier;
Depending on the reception state of the mobile station, a code multiplex single type spread code, or a spread code creation means for creating a code multiplex and frequency multiplex combination code from an orthogonal code,
A control channel multiplexer comprising:   The control channel multiplexing apparatus according to claim 1, wherein the orthogonal code is a Walsh-Hadamard code or a rotation orthogonal code.   A wireless communication apparatus comprising the control channel multiplexing apparatus according to claim 1. A control channel multiplexing method for multiplexing a plurality of control channels assigned to each mobile station,
Code spreading multiplexing the plurality of control channels using orthogonal codes;
A process of inverse Fourier transforming a frequency domain signal obtained by the code spread multiplexing into a time domain signal as a continuous subcarrier;
Depending on the reception state of the mobile station, a process of creating a code multiplex single type spread code or a code multiplex and frequency multiplex spread code from orthogonal codes;
A control channel multiplexing method comprising:

Images