JP2003018127A - Transmitter and receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize formation of desired sector zones and transmission diversity, under common usage of a multibeam antenna in a transmitter and a receiver, to which a time-space coding system and a multi-carrier modulation system are applied. SOLUTION: The transmitter comprises a time/space coding means 11 for time/space coding transmission information to generate time/space code strings separately corresponding to the beams, based on a time/space coding matrix having a number of columns which is not less than a number P of beams formed by an array antenna 10, a plurality P of beam forming means 12-1 to 12-P for phase-shifting the strings of these time/space codes in parallel at their respective phase shift quantities, applied separately for feeding a plurality E of elements which the antenna 10 has, thereby generating a plurality (<= P.E) of phase-shifted time/space code strings, and a plurality E of transmitting means 13-1 to 13-E for multi-carrier modulating and transmitting the phase shifted time/space code strings.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmitter and a receiver provided at a transmission end and a reception end, respectively, in a radio transmission system to which a space-time coding system and a multicarrier modulation system are applied.

[0002]

2. Description of the Related Art Next-generation mobile communication systems and wireless LANs
Are required to have a high transmission speed of several tens of megabits / second or more. Therefore, in such a wireless transmission system,
In order to avoid bit errors due to multipaths, which occur remarkably at higher transmission rates regardless of signal power, orthogonal frequency division multiplexing (OFDM: ODM)
rthogonal frequency division multiplexing) and MC-
In addition to CDMA (Muticarrier CDMA) and the like, application of space-time coding that enables improvement of transmission quality based on the diversity effect is being promoted.

FIG. 7 is a diagram showing a configuration example of a wireless transmission system to which MC-CDMA and space-time coding are applied. Figure 6
The wireless transmission system shown in FIG.
Composed of. The transmission device 70 includes the following elements. -Two antennas 71-which are installed at positions separated from each other so that the gain improvement based on the transmission diversity is realized.
1, 71-2 ・ Modulator (MOD) 72 to which transmission information is given to input ・ Space-time coding unit 73 cascade-connected to modulator 72 ・ Two outputs of space-time coding unit 73 and antenna 7
The multiple connection parts 74-1 and 74-2 arranged between the power supply points 1-1 and 71-2, respectively, and the multiple connection part 74-1 are composed of the following elements.

The spreader 75-1 arranged in the first stage has a first input individually connected to a plurality of outputs (equal to the number n of sub-channels described later) of the spreader 75-1. Adder (Σ) 76-11 to 76-1n · has n inputs individually connected to the outputs of these adders 76-11 to 76-1n, and the output is connected to the feeding point of the antenna 71-1. Connected IDFT unit 77-1 Since the configuration of the multiple-connection unit 74-2 is the same as the configuration of the multiple-connection unit 74-1, the corresponding components will be referred to as “first sub-number” below. “2” is given instead of “1”, and the description and illustration will be given here.

Further, adders (76-12 to 76-1n), (76-
22 to 76-2n) and the other inputs to the diffusers 75-1 and 75-1, respectively.
Outputs of spreaders (not shown) different from 75-2 are respectively connected, and modulators and space-time encoding units (which are different from the modulator 72 and space-time encoding unit 73) are connected in front of these spreaders. (Not shown)) are individually arranged.

The receiving device 80 is composed of the following elements. -Antenna 81-DFT unit 82 in which the feed point of the antenna 81 is connected to the input-Channel estimation units 83-1 to 83 having inputs respectively connected to the first to nth outputs of the DFT unit 82
-n ・ DF together with the inputs of the channel estimation units 83-1 to 83-n
A decoder (DE) having inputs respectively connected to the first to nth outputs of the T section 82 and having control terminals individually connected to the outputs of these channel estimators 83-1 to 83-n.
C) 84-1 to 84-n Despreader 85 having n inputs respectively connected to outputs of decoding units 84-1 to 84-n. Cascaded to despreader 85 and transmitted to output. Information determining signal determiner 86 In the wireless transmission system having such a configuration, the modulator 72 provided in the transmitting device 70 uses a predetermined modulation method (here, for simplicity, it is assumed that the modulation information is QPSK for transmission information). This transmission information is converted into a sequence of symbols by performing modulation based on (.

The space-time encoding unit 73 includes two symbols S _t , which are consecutively included in the symbol sequence in the order of time series _t ,
The following processing is sequentially performed in parallel according to the pair S _{t + 1} . A column [S _t , S _{t + 1} ] of elements in the first row of the space-time coding matrix A (hereinafter, referred to as “first partial space-time code sequence”) is generated, and the multiple access unit 74-1 is generated. (Diffuser 75-1).

[0008]

[Equation 1] The column [-S _t ^* , S of the second row element of the space-time coding matrix A
_{t + 1} ^* ] (hereinafter, referred to as “second partial space-time code string”) is generated and given to the multiple access unit 74-2 (spreader 75-2).
An element with a superscript "*" as in the above second partial space-time code string means a complex number that is conjugate to the complex number with the "*" added.

The diffuser 75-1 performs the following processing. -The above-mentioned first partial space-time code string has a predetermined word length (here, for simplicity, the number n of the input terminals of the IDFT unit 77-1 is n.
Assume that there are n bits when equal to. ), The word length is constant (= n bits)
Produces a sequence of words that is.

A logical value of each bit forming these words (hereinafter, information given as a string of such logical values is referred to as a “partial bit string”) and a predetermined first spreading code (here, it is referred to as “partial bit string”). , For the sake of simplicity, it is assumed that it is a “Walsh code” having an n-bit length.) By performing a logical multiplication of the logical value of the corresponding bit of n), n different virtual subcarriers can be obtained. The n sub-channel signals (hereinafter, referred to as “first sub-channel signals”) that are modulated by the corresponding partial bit strings are sequentially generated.

A predetermined bit string (hereinafter, referred to as “n”) having excellent cross-correlation characteristics is added to these n first sub-channel signals.
It is called a "pilot series". ) Is multiplexed. In addition, the spreader 75-2 performs the same processing as the above-described processing performed by the spreader 75-1 in parallel according to the second partial space-time code sequence instead of the first partial space-time code sequence. The above-mentioned pilot sequences are individually multiplexed to generate n “second sub-channel signals”.

The IDFT unit 77-1 includes adders 76-11 to 7-7.
By performing an inverse discrete Fourier transform of these first sub-channel signals (including pilot sequences) provided via 6-1n and adding a guard interval,
The "first transmission wave signal", which is a time signal, is generated, and the "first transmission wave signal" is transmitted to the receiving device 80 via the antenna 71-1.

Further, the IDFT unit 77-2 has an IDFT unit 7-2.
7-1 is a time signal by performing the same processing as that described above in parallel according to the second sub-channel signal (including the pilot sequence) in place of the first sub-channel signal. Generate a "second transmitted wave signal",
The second transmission wave signal is transmitted to the receiving device 80 via the antenna 71-2.

The adders 76-11 to 7-11 together with the above-mentioned first sub-channel signal and second sub-channel signal.
6-1n, 76-21 to 76-2n through the IDFT unit 77-1,
The sub-channel signals respectively given to 77-2 are generated as a result of the spreading processing based on the individual spreading code orthogonal to the above-mentioned first spreading code, and are formed between them with the receiving device 80. Since the signals are transmitted via different radio channels corresponding to the spreading codes, detailed description thereof will be omitted here for simplicity.

On the other hand, in the receiver 80, at the feeding point of the antenna 81, the antennas 71-1 and 71-2 and the antenna 8 thereof are provided.
The transmission characteristics h1 and h2 of the two wireless transmission lines formed individually between 1 and 1 are represented by the following equations (2) and (3) with respect to the time series t. Received waves r _t and r _{t + 1} , which are vector sums of radio frequency signals arriving in parallel, are sequentially obtained.

R _t = h 1 · S _t + h 2 · S _{t + 1} (2) r _{t + 1} = −h ₁ · S _t ^* + h 2 · S _{t + 1} ^* (3) The DFT unit 82 includes the transmitter 70. At IDFT section 77
−1, 77-2 is applied to these received waves r _t , r _{t +1} which is the inverse of the inverse discrete Fourier transform performed by -1, 77-2 to generate n sub-channel signals in parallel.

The channel estimation units 83-1 to 83-n and the decoding units 84-1 to 84-n respectively perform the following common processing in parallel according to these sub-channel signals. It should be noted that in the following, regarding these processes, the subscript “1” to
It is described by adding a subscript “C”, which means that it corresponds to any of “n”, to the corresponding code.

The channel estimation unit 83-C correlates the C-th sub-channel signal of the n sub-channel signals generated by the DFT unit 82 with the pilot sequence to be included in the sub-channel signal. Therefore, the estimated values h1 ^ _C and h2 ^ _C of the transmission characteristics of the two wireless transmission paths described above are obtained.
Ask for. The decoding unit 84-C substitutes the values s _Ct and s _{Ct + 1 of} the C-th sub-channel signal described above into the left sides of the above equations (2) and (3), respectively, and estimates the estimated value h1 on the right side of these equations. ^ _C and h2 ^ _C are substituted into the transfer characteristics h1 and h2, respectively, to obtain solutions S _Ct and S _{Ct + 1} of the following simultaneous equations (4) and (5), and the space-time in the transmitter 70 is obtained. Space-time decoding matching the space-time encoding performed by the encoder 73 is performed.

S _Ct = h1 ^ _C · S _Ct + h2 ^ _C · S _{Ct + 1} (4) s _{Ct + 1} = −h1 ^ _C · S _Ct ^* + h2 ^ _C · S _{Ct + 1} ^* (5) In this way, the despreader 85 decodes the decoding units 84-1 to 84-n.
By the spreaders 75-1 and 75-2 in the transmitter 70 for the n sub-channel signals S _{1t to} S _{nt + 1} obtained in parallel by A demodulated signal is generated by performing despreading processing which is the opposite of the above.

The signal determination unit 86 restores the above-mentioned transmission information by obtaining the sequence of the nearest signal points where the individual symbols included in the demodulated signal in the order of time series are located on the signal space diagram. Therefore, in such a conventional example, by combining the transmission diversity in which space-time coding is used in combination with the MC-CDMA system, the transmission quality due to multipath can be improved even when the desired transmission rate is high. Deterioration is avoided with high accuracy.

As a prior art similar to the above-mentioned conventional example, for example, a beam formed by a transmission switched beam array antenna is generated by space-time coding based on the space-time coding matrix A described above. There is a technique for assigning codes.

[0022]

By the way, in the above-described conventional example, it is possible to realize both a large reduction of delay dispersion, which is a main factor of deterioration of transmission quality of a mobile communication system, and a high transmission rate. Nevertheless, it was difficult to apply to the next-generation mobile communication system because it does not match the following points. In order to achieve effective utilization of radio frequency in combination with various zone configurations, channel arrangements and services, the intervals are set so narrow that the diversity gain due to the above-mentioned transmission diversity cannot be obtained, and desired. The adaptive array antenna that realizes the sector configuration and directivity must be applied to many radio base stations.

In addition, in a radio base station of a mobile communication system to which such an adaptive array antenna is applied, in order to ensure the reversibility of the uplink and downlink radio lines formed with a terminal, The transmitting antenna is required to have the same directivity and performance. However, such an adaptive array antenna is unsuitable for both transmission and reception, and thus has a high possibility of becoming a main factor of cost increase.

Further, in a radio base station that receives signals via the adaptive array antenna, weights such as the amount of phase shift to be applied to the phase shift feeding of the individual elements of the adaptive array antenna (hereinafter referred to as "array weight"). Is generally set individually according to the sector and direction in which the terminal is located. However, in such a radio base station, when the array weight set for each terminal as described above is applied to the adaptive array antenna used for transmission, the downlink to be formed between each terminal is also applied. Since there is an unnecessary difference in the transmission characteristics of the wireless communication line of MC-C,
Orthogonality between channels multiplexed based on the DMA method is not guaranteed.

In addition, the above-mentioned prior art was not practically applicable because the transmission quality of the channel formed via the beam allocated to each terminal deteriorates due to the following interference. -If the arrival angle of the received wave to the terminal is wide, interference occurs due to other beams that arrive as the reflected wave.

Even if the angle of arrival is small, if the side lobe of the beam antenna is large,
Interference is caused by other beams arriving through that side lobe. It is an object of the present invention to provide a transmitting device and a receiving device that can surely realize transmission diversity under the common use of a multi-beam antenna while forming a desired sector and a radio zone.

[0027]

FIG. 1 is a block diagram of the first principle of a transmitting device according to the present invention. In the invention according to claim 1, the space-time coding means 11 performs space-time coding on the transmission information based on a space-time coding matrix having columns of the number P of beams formed by the array antenna 10 or more,
A sequence of space-time codes corresponding to these beams is generated. The beam forming means 12-1 to 12-P shift the rows of the space-time codes in parallel over a phase shift amount individually adapted to feed the elements of the plurality E of the array antenna 10 to shift the phase in parallel. A sequence of phase-shifting space-time codes of (≦ P · E) is generated. Transmitting means 13-1 to 13-E are beam forming means 12-1 to 12
The phase-shifted space-time code sequence generated by -P and individually corresponding to the plurality of E elements described above is multicarrier-modulated and transmitted in parallel through these elements.

In this way, between the rows of phase-shifting space-time codes that arrive in parallel via the main lobes of the individual beams formed by the array antenna 10 and the side lobes of the beams different from that beam. The orthogonality is secured by the space-time coding described above. Therefore, in addition to formation of a desired sector or radio zone by the array antenna 10, transmission diversity by the plurality of E elements included in the array antenna 10 is surely achieved.

FIG. 2 is a block diagram of the second principle of the transmitting apparatus according to the present invention. According to the invention of claim 2,
The beam forming means 12A-1 to 12A-P have a bit string equal to the number P of beams formed by the array antenna 10 over a phase shift amount individually adapted to feed a plurality of E elements of the array antenna 10. The phase of the transmission information given as is shifted in parallel to generate a sequence of P pieces of phase-shifted transmission information. The space-time coding means 11A corresponds to each beam by performing space-time coding on the columns of the phase-shifted transmission information in parallel based on the space-time coding matrix having columns of the number P of beams described above. Generate a sequence of space-time codes. The transmitting means 13A-1 to 13A-E multi-carrier modulate the sequence of space-time codes generated in this way, and transmit in parallel via a plurality of E elements.

That is, the order of the above-described processing performed by the beam forming means 12A-1 to 12A-P and the space-time coding means 11A in this manner is the same as those performed by the invention described in claim 1. The opposite of the order of. But,
Since all of these processes are linear processes, the signals transmitted in parallel via the respective elements of the array antenna 10 are basically the same signals.

Therefore, similarly to the invention described in claim 1, the transmission diversity is surely achieved by the plurality of E elements included in the array antenna 10 along with the formation of the desired sector or the radio zone by the array antenna 10. It According to a third aspect of the invention, in the transmitting apparatus according to the first or second aspect, the transmission information is given as a plurality of p pieces of transmission information which is equal to or less than the number P of beams to be formed by the array antenna 10. .

That is, these plural pieces of transmission information of p are
In the process of space-time coding, multiplexing is performed while ensuring orthogonality. Therefore, even when the number of pieces of transmission information to be transmitted in parallel via the array antenna 10 increases or decreases or is large, the maximum multiplexing degree of the multiplexing process to be performed after the above-mentioned space-time encoding is It is suppressed to a small value.

FIG. 3 is a block diagram showing the principle of the receiving apparatus according to the present invention. In the invention according to claim 4, the separating means 21 is space-time coded based on a space-time coding matrix having columns of the number of beams P or more formed by the array antenna 20 installed at the transmitting end, and multi-coded. The received wave that has been carrier-modulated and has arrived from the array antenna 20 is separated for each sub-channel component. The channel estimation means 22-1 to 22-P estimate the characteristics of P wireless transmission paths formed in parallel with the antenna array 20. The decoding means 23 performs space-time decoding of the components of these sub-channels on the basis of the space-time coding matrix described above and the characteristics estimated by the channel estimation means 22-1 to 22-P, thereby transmitting the transmission information. Restore.

Between the main lobes of the individual beams formed by the above-mentioned array antenna 20 and the received waves arriving in parallel via the side lobes of the beams different from the beams, the above-mentioned space-time decoding is performed. This ensures orthogonality. Therefore, in addition to formation of a desired sector or radio zone by the array antenna 20, transmission diversity by the plurality of E elements included in the array antenna 20 is surely achieved.

In the invention described in claim 5, the received wave is
Beam identification information that individually indicates the beams formed by the array antenna 20 is multiplexed. The channel estimation means 22-1 to 22-P use the antenna array based on the correlation between the components of the individual sub-channels separated from the received wave by the separation means 21 and the beam identification information individually indicating the number P of beams. The characteristics of P wireless transmission lines formed in parallel with 20 are estimated.

That is, at the receiving end, channel estimation of the transmission path actually used for the transmission of these space-time codes can be performed on the basis of the correlation with the beam identification information contained in each received reception wave. . Therefore, the precision of the space-time decoding performed based on the result of such channel estimation is stably maintained high even when the characteristics of the above-mentioned transmission path may change every moment.

In the invention of the subordinate concept of the third aspect of the invention, the space-time encoding means 11 and 11A allocate elements to these transmission information in a number matching the ratio of the information amount of the plurality of p transmission information. Space-time encoding is performed based on the space-time encoding matrix. That is, the deviation of the time required for each transmission of the plurality of p pieces of transmission information described above is suppressed to a small value even when the information amounts of these pieces of transmission information are different.

Therefore, the transmission quality and the real time property are maintained high. In the first invention related to the invention described in claim 3, the space-time coding support means 14 indicates that the allocation of the elements of the space-time coding matrix to the plurality of p pieces of transmission information should be updated. Send a notification to the receiving end. That is, it is possible to flexibly change the space-time coding form according to the change in the information amount of the transmission information, the service class, and other attributes, based on the cooperation with the receiving end.

Therefore, the flexibility of adapting to various needs related to maintenance and operation can be enhanced. In the first invention related to the invention described in claims 1 to 3,
The transmitting means 13-1 to 13-E and 13A-1 to 13A-E perform spreading processing in the frequency domain for each sub-channel adapted to the multicarrier modulation method.

That is, the sequence of the space-time code obtained by the space-time encoding and some transmission information different from the sequence of the space-time code may significantly increase or decrease the speed at which both or one of them should be transmitted. Even in such a case, parallel transmission is performed based on a multiple access method capable of suppressing deterioration of transmission quality due to multipath. Therefore, even when the amount of transmission information to be wirelessly transmitted in parallel can vary widely, the quality of service is maintained high.

In the second invention related to the invention described in claims 1 to 3, the transmitting means 13-1 to 13-E, 13 are provided.
A-1 to 13A-E multiplex sub-channel signals generated by spreading processing in the frequency domain based on different spreading codes for each sub-channel. That is, the space-time code sequence obtained by space-time encoding, and some transmission information different from the space-time code sequence, even if the transmission speed of both or either one is significantly high,
Parallel transmission is performed based on a multiple access scheme in which deterioration of transmission quality due to multipath is suppressed.

Therefore, even when the amount of transmission information to be transmitted in parallel is extremely large, the quality of service is maintained high. In the third invention related to the invention described in claims 1 to 3, the space-time coding means 1 is provided.
1 and 11A perform space-time encoding based on a space-time encoding matrix in which the number of columns matches the total amount of information of transmission information.

That is, as long as the receiving end can identify the space-time coding matrix applied to the above-mentioned space-time coding and the transmission information to which each element of the space-time coding matrix is assigned, Regardless, a high transmission quality based on transmit diversity and a desired radio zone (sector) are achieved together. In the fourth invention related to the inventions described in claims 1 to 3, the space-time coding support means 14A indicates that when the space-time coding matrix applied to the space-time coding should be changed. Send the notification to the receiving end.

That is, the space-time coding matrix to be applied to the space-time decoding at the receiving end is the space-time coding matrix used for the space-time coding at this transmitting end under the cooperation of the receiving end and the transmitting end. Highly maintained in the same space-time coding matrix as. Therefore, the number of information to be transmitted in parallel, the amount of information,
Even when the speed and other attributes may change, the high transmission quality based on the transmission diversity and the desired wireless zone (sector) are maintained in a stable manner.

In the fifth invention related to the invention described in claims 1 to 3, the space-time coding means 11, 11A is provided.
Adds small beam identification information individually corresponding to the beam to be formed by the array antenna 10 and having excellent cross-correlation to the space-time code sequence corresponding to the beam identification information. That is, at the receiving end, channel estimation of the transmission path actually used for transmission of these space-time codes can be performed based on the correlation with the beam identification information added to each received sequence of space-time codes. .

Therefore, the accuracy of the space-time decoding performed based on the result of such channel estimation can be stably maintained high even when the characteristics of the above-mentioned transmission path can change every moment. In the sixth invention related to the invention described in claims 1 to 3, the transmission characteristic acquisition means 15 is notified by the receiving end, and is formed separately between the array antenna 10 and the receiving end. Acquire the transmission characteristics of the wireless transmission path. The space-time coding means 11 and 11A include the transmission characteristic acquisition means 15 among the elements of the space-time coding matrix used for the space-time coding of the above-described transmission information to be transmitted to the receiving end.
Elements that match the combination of transmission characteristics obtained by are assigned to the receiving end.

That is, the elements of the space-time coding matrix used for the space-time coding performed when transmitting the transmission information are assigned to the transmission information according to the transmission characteristics of the radio transmission path formed between the transmission end and the receiving end. . Therefore, such transmission information is subjected to space-time coding adapted to the above-mentioned change in the transmission characteristic and is sequentially transmitted to the receiving end.

In the invention of the subordinate concept of claim 4 or claim 5, the received wave is generated under the spread processing in the frequency domain. The decoding means 23 restores the transmission information by subjecting the result of the space-time decoding to despreading processing that matches such spreading processing. That is, a sequence of space-time codes obtained by space-time coding at the transmitting end,
Some kind of transmission information different from the space-time code sequence means that deterioration of transmission quality due to multipath can be suppressed even if the transmission speed of both or any one of them can significantly increase or decrease. It is transmitted in parallel according to the possible multiple access schemes.

Therefore, even if the information amount of the transmission information to be wirelessly transmitted in parallel can vary widely,
Good service quality is maintained with high accuracy. In the invention related to the invention described in claim 4 or claim 5, the notifying means 24 includes P number of the beams formed by the array antenna 20 estimated by the channel estimating means 22-1 to 22-P. The transmitting end is notified of a single beam or a plurality of beams corresponding to the descending order of transmission quality achieved based on the characteristics of the wireless transmission path.

That is, the transmission source can specify a beam, of the beams formed by the array antenna 20, for which the transmission quality of the downlink radio transmission line is substantially good, without performing the processing autonomously. it can. Therefore, without significantly increasing the amount of processing that should be secured at the transmitting end,
Along with an increase in gain based on transmission diversity, suppression of interference based on a desired radio zone (sector) is realized.

[0051]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 4 is a diagram showing the first to third embodiments of the present invention. In the figure, those having the same functions and configurations as those shown in FIG.
The same reference numerals are given and shown, and the description thereof is omitted here. The main difference between this embodiment and the conventional example shown in FIG. 7 is the transmitting device 3 provided in place of the transmitting device 70.
0 and the configuration of the receiving device 40 provided in place of the receiving device 80.

The main differences between the configurations of the transmitting device 30 and the transmitting device 70 are as follows. -Instead of the antennas 71-1 and 71-2, the antennas 31-1 to 31-1 to
31-4 is provided. -Individual transmission information (hereinafter, "first transmission information", "second transmission information") by two different subscribers (users)
Say. ) 72 to which modulators (MOD) 72 are respectively given
-1, 72-2 are provided instead of the modulator 72.

A space-time encoding unit 32 having two inputs individually connected to the outputs of the modulators 72-1 and 72-2 is provided instead of the space-time encoding unit 73. -The multiple connection parts 33-1 to 33-4 connected to the feeding points of the antennas 31-1 to 31-4 are the multiple connection parts 74-1 and 7-4.
It is provided instead of 4-2. Beam forming units 34-1 to 34-4 having four outputs respectively connected to the first input to the fourth input of the multiple access units 33-1 to 33-4 are provided.

Multiplexing that is individually arranged between the four outputs of the space-time coding unit 32 and the inputs of the beam forming units 34-1 to 34-4 and is given different pilot sequences PS1 to PS4, respectively. Parts (MUX) 35-1 to 35-4 are provided. In addition, the multiple connecting section 33-1 and the multiple connecting section 74
-1 is different from the configuration of -1 in that an adder 36-1 having four inputs directly connected to the corresponding outputs of the beam forming units 34-1 to 34-4 is arranged in the preceding stage of the spreader 75-1. There is a point.

The structure of the multi-connection parts 33-2 to 33-4 is the same as that of the multi-connection part 33-1.
In the following, subscripts “2” to “4” are added to corresponding components.
The same reference numeral is added, and the description and illustration thereof are omitted here. The main differences between the configurations of the receiving device 40 and the receiving device 80 are as follows. Channel estimation units 41-1 to 41-4 are provided in place of the channel estimation units 83-1 to 83-n.

Control terminals which are provided in place of the decoding units 84-1 to 84-n and which are directly connected to the corresponding four outputs among the outputs of the channel estimation units 41-1 to 41-4 having n pieces each. Decoding units (DEC) 42-1 to 42-n each having the above are provided. The operation of the first embodiment of the present invention will be described below with reference to FIG. The modulators 72-1 and 72-2 perform modulation processing in parallel according to the first transmission information and the second transmission information described above, and two modulators that respectively show these transmission information in the order of time series t. The sequence of symbols S ₁ (t) and S ₂ (t) is output.

The space-time encoding performed by the space-time encoding unit 32 differs from the conventional example in the points listed below. The symbols S ₁ (t + 1) and S ₂ (t + 1) at time (t + 1) following these symbols are combined with the above-mentioned symbols S ₁ (t) and S ₂ (t) at time t. The following space-time coding matrix M
The symbols M _1,2 allocated to the elements of are applied instead of the space-time coding matrix A already described.

[0058]

[Equation 2]

[Equation 3] The parallel output of the first to fourth “space-time code strings” composed of columns of elements of each column of the space-time encoding matrix M _1,2 . In the following, as shown in FIG. 5, a plurality of beams to be formed under the phase-shift feeding to the antennas 31-1 to 31-4 (here, for simplification, each of the beams is individually divided into four sector zones. It is assumed that they correspond to each other), and the multiplexing units 35-1 to 35-4 and the beam forming unit 3
For the processes performed in parallel by 4-1 to 34-4, a subscript "B" (= 1 to 4) indicating that any of these beams can be applied is added to the code of each component. Described by

The multiplexing unit 35-B shows the beam corresponding to the multiplexing unit 35-B among the above-mentioned plurality of beams.
A pilot sequence PSB consisting of a bit string having a small cross-correlation is given. Further, the multiplexing unit 35-B multiplexes this pilot sequence PSB into a corresponding single space-time code string among the above-mentioned first to fourth space-time code strings, thereby showing, for example, in FIG. A "beam-corresponding signal" is generated as a sequence of frames of such a predetermined format.

The beam forming unit 34-B performs, on the corresponding beam-corresponding signal, for example, four types of phase shift processing necessary for phase-shift feeding of the above-mentioned antennas 31-1 to 31-4 in the baseband region, for example. By applying in parallel, four "phase shift signals" are generated. Of the phase shift signals, the adders 36-1 to 36-4 respectively receive the antennas 31-1 to 31-4.
By taking in parallel the sum of the four phase-shifted signals, the spreaders 75-1 to 75-4 and the adders 76-11 to 76-1
n, ..., 76-41 to 76-4n and IDFT unit 77-1 to 7-7
A transmission signal to be used for feeding these antennas 31-1 to 31-4 is generated via 7-4.

The diffusers 75-1 to 75-4 and the adder 76
-11 to 76-1n, ..., 76-41 to 76-4n and the processing performed by the IDFT units 77-1 to 77-4 are the spreaders 75-1 and 75-2 and the adder 76- in the conventional example. 11 ~ 7
6-1n, 76-21 to 76-2n and IDFT section 77-1 to 7
Since it is basically the same as the processing performed by 7-2,
Here, the detailed description is omitted.

On the other hand, in the receiver 40, at the feeding point of the antenna 81, the antennas 71-1 to 71-4 and the antenna 8 thereof are provided.
For the transmission characteristics h1, h2, h3, h4 and the time series t of the four wireless transmission lines individually formed between the following equations (6) to (1
Indicated by 3), the received wave r _t ~r is the vector sum of the radio frequency signal arriving in parallel via these radio transmission path
_{t + 7} is obtained sequentially.

R _t = h1 · S ₁ (t) + h2 · S ₁ (t + 1) + h3 · S ₂ (t) + h4 · S ₂ (t + 1) _{... (6) r t + 1} = -h1 · S 1 (t + 1) + h2 · S 1 (t) -h3 · S 2 (t + 1) + h4 · S 2 (t) _{... (7) r t + 2} = -h1 · S 2 (t) + h2 · S 2 (t + 1) + h3 · S 1 (t) -h4 · S 1 (t + 1) _{... (8) r t + 3} = -h1 · S 2 (t + 1) -h2 · S 2 (t) ＋ h3 ・ S ₁ (t + 1) ＋ h4 ・ S ₁ (t) _{... (9) r t + 4} = h1 · S 1 (t) * + h2 · S 1 (t + 1) * + h3 · S 2 (t) * + h4 · S 2 (t + 1) * ... (10) r _{t + 5 = -h1 · S 1} (t + 1) * + h2 · S 1 (t) * -h3 · S 2 (t + 1) * + h4 · S 2 (t) * ... (11) r t + 6 _{= -h1 · S 2 (t)} * + h2 · S 2 (t + 1) * + h3 · S 1 (t) * -h4 · S 1 (t + 1) * ... (12) r t + 7 = -h1 _{· S 2 (t + 1)} * -h2 · S 2 (t) * + h3 · S 1 (t + 1) * + h4 · S 1 (t) * ... (13) DFT unit 82, IDFT in the transmitter 70 Department 77-1 to 7
By applying a discrete Fourier transform opposite to the inverse discrete Fourier transform performed by 7-4 to these received waves r _{t to} r _{t + 7} , n sub-channel signals are generated in parallel.

In the following, the channel estimation units 41-1 to 41-1 ...
For the processing performed in parallel by 41-4, the subscript "c" indicating that it can correspond to any of these channel estimation units 41-1 to 41-4 or the plurality of beams described above is applied. Describe. Furthermore, the decoding units 42-1 to 4-4
The processing performed in parallel by 2-n will be described by applying the subscript "C" (= 1 to n) indicating that it can correspond to any of the above-mentioned sub-channel signals.

The channel estimator 41-c takes in parallel the correlation between the n sub-channel signals generated by the DFT unit 82 and all pilot sequences that may be included in these sub-channel signals. Estimated values h1 ^ _C , h2 ^ _C , h3 ^ _C of the transmission characteristics of the above-described four beams (including side lobes) that are individually formed via the sub-channel corresponding to the subscript "C" described above. , H4 ^ _C.

In the decoding unit 42-C, the values s _{C ( t) to} s _{C (t + 7) of} these sub-channel signals obtained in the order of the time series t are calculated on the left side of the above equations (6) to (13). And the estimated values h1 ^ _C , h2 ^ _C , h3 ^ _C , and h4 ^ _C are substituted as the transfer characteristics h1, h2, h3, and h4 on the right side of these equations, respectively. Solutions S _C1 (t) of equations (14)-(21),
S _C1 (t + 1), S _C2 (t), S _C2 (t + 1), S _C1 (t) ^* , S _C1 (t + 1)
^{By obtaining *} , S _C2 (t) ^* , and S _C2 (t + 1) ^* , the space-time coding unit 32 and the beam forming unit 34 in the transmitter 30 are obtained.
-1 to 34-4 and space-time decoding matching the space-time encoding performed under the cooperation of the adders 36-1 to 36-4.

S _{C (t)} = h1 ^ _C · S _C1 (t) + h2 ^ _C · S _C1 (t + 1) + h3 ^ _C · S _C2 (t) + h4 ^ _C · S _C2 (t + 1) … (14) s _{C (t + 1)} = -h1 ^ _C · S _C1 (t + 1) + h2 ^ _C · S _C1 (t) −h3 ^ _C · S _C2 (t + 1) + h4 ^ _C · S _C2 (t) … (15) s _{C (t + 2)} = -h1 ^ _C · S _c2 (t) + h2 ^ _C · S _C2 (t + 1) + h3 ^ _C · S _C1 (t) −h4 ^ _c · S _C1 ( t + 1) _{... (16) s C (t} + 3) = -h1 ^ C · S C2 (t + 1) -h2 ^ C · S C2 (t) ＋ h3 ^ _C・ S _C1 (t + 1) ＋ h4 ^ _C・ S _C1 (t) … (17) s _{C (t + 4)} = h1 ^ _C · S _C1 (t) ^* ＋ h2 ^ _C · S _C1 (t + 1) ^* ＋ h3 ^ _C・ S _C2 (t) ^* ＋ h4 ^ _C・ S _C2 (t + 1) ^* … (18) s _{C (t + 5)} ＝ −h1 ^ _C・ S _C1 (t + 1) ^* ＋ h2 ^ _C・ S _C1 (t) ^* −h3 ^ _C・ S _C2 (t + 1) ^* ＋ h4 ^ _C・ S _C2 (t) ^* … (19) s _{C (t + 6)} = −h1 ^ _C・ S _C2 (t) ^* ＋ h2 ^ _C・S _C2 (t + 1) ^* + H3 ^ _C・ S _C1 (t) ^* −h4 ^ _C・ S _C1 (t + 1) ^* … (20) s _{C (t + 7)} = −h1 ^ _C・ S _C2 (t + 1) ^* −h2 ^ _C・ S _C2 (t) ^* + H3 ^ _C · S _C1 (t + 1) ^* + h4 ^ _C · S _C1 (t) ^* (21) The despreader 85 thus decodes the decoding units 42-1 to 42-n.
(N × 8) sub-channel signals S ₀₁ (t) to S ₇₁ (t), which are obtained in parallel by and are given in the order of time series t.
S ₀₁ (t + 1) to S ₇₁ (t + 1), S ₀₂ (t) to S ₇₂ (t), S ₀₂ (t + 1)
~ S ₇₂ (t + 1), the spreader 75-1 in the transmitter 70 ~
A demodulation signal is generated by performing the processing opposite to the spreading processing performed by 75-4.

The signal decision section 86 outputs the sequence of the nearest signal points on the predetermined signal space diagram for each symbol included in the demodulated signal in the order of the time series.
Restore transmission information. Thus, according to the present embodiment,
All the transmission signals transmitted in parallel via the antennas 31-1 to 31-4 and forming a desired beam by these antennas 31-1 to 31-4 are space-time encoded provided in the transmission device 30. Unit 32, multiplexing units 35-1 to 35-4, beam forming units 34-1 to 34-4, and adders 36-1 to 36-4 based on the space-time coding matrix M _1,2 described above. The space-time decoding processing which is generated under the conventional space-time coding and which is adapted to such space-time coding is similarly performed centrally in the receiving device 40.

Further, in the process of such space-time coding, the components of the transmission signal transmitted via the side lobes of the individual beams shown by the dotted lines and the broken lines in FIG. 5 and the main lobes of these beams are transmitted. Orthogonality is secured between the transmission signals transmitted in parallel under the space-time coding processing described above. Further, in the present embodiment, since the spreading process is performed on the space-time code sequence obtained by space-time coding a plurality of pieces of transmission information, individual spreading codes must be applied to the transmission of these pieces of transmission information. MC-CDMA which does not become
Compared to the system, even if the number of transmission information is the same, the number of spreading codes can be reduced, and the overall transmission quality can be improved.

Therefore, in the radio transmission system according to the present embodiment, transmission diversity is surely achieved along with formation of a desired sector or radio zone by a plurality of phase-shift-powered antennas. Note that in the present embodiment, the channel estimation unit 41-c obtains the above-mentioned estimated value h1 ^ by taking the correlation with the above-described pilot sequence for each sub-channel signal.
_C , h2 ^ _C , h3 ^ _C , h4 ^ _C are sought.

However, the present invention may be configured without the channel estimation unit 41-c in any of the following cases, for example. When the variation of the characteristics of the wireless transmission path between both the transmitting apparatus 30 and the receiving apparatus 40 is minute, the estimated value flexibly adapted to such characteristic variation is separately provided by means for realizing channel control or the like. When required, the second embodiment of the present invention will be described below.

The main difference between this embodiment and the above-described first embodiment lies in the procedure of the following processing performed by the space-time coding unit 32. The space-time coding unit 32 performs space-time coding based on the following space-time coding matrix m _1,2 instead of the above-described space-time coding matrix M _1,2 .

[Equation 4] Each row of such a space-time coding matrix m _1,2 includes three elements corresponding to the first transmission information and a single element corresponding to the second transmission information.

However, such a space-time coding matrix m _1,2
Even when the above is applied, the space-time coding unit 32, the multiplexing units 35-1 to 35-4, the beam forming units 34-1 to 34-4, and the adder 36-1 provided in the transmission device 30. ~ 36-4,
The basic procedure of the calculation performed by the DFT unit 82, the channel estimation units 41-1 to 41-4, and the decoding units 42-1 to 42-n included in the reception device 40 is the same as the first procedure described above. The comparison with the embodiment is basically the same.

That is, by appropriately allocating the elements of the space-time coding matrix m _{1,2 to} the above-mentioned first transmission information and second transmission information, the information amount of these transmission information,
Alternatively, it is possible to flexibly adapt to the speed at which both transmission information should be transmitted. Therefore, according to the present embodiment, transmission information of various information amounts and transmission rates is flexibly multiplexed in the process of space-time encoding, and the number of spreading codes to be used for transmission of these transmission information is ensured. Reduction is achieved.

In this embodiment, the first transmission information and the second transmission information are multiplexed in the space-time coding process. However, the number of pieces of transmission information to be multiplexed in such a space-time encoding process may be any value as long as it is equal to or smaller than the number of columns forming the space-time encoding matrix.

In the present embodiment, the channel estimation unit 4
The 1-1 to 41-4 and the decoding units 42-1 to 42-n include a space-time coding matrix applied to the space-time coding in the transmission device 30 and the space-time allocated to each transmission information. The elements of the encoding matrix are given in advance as known information. However, whether or not these space-time coding matrices and elements are updated under the cooperation of the transmission device 30 and the reception device 40, or under the initiative of either one of them. However, it may be separately obtained by means of performing channel control or other processing.

The third embodiment of the present invention will be described below. The main difference between the present embodiment and the above-described first embodiment is that the receiving device 40 is indicated by the dotted line in FIG.
Instead of this, a receiving device 40A is provided. The difference between the configurations of the receiving device 40A and the receiving device 40 is that the following elements are added.

Inputs that are directly connected to the outputs of the channel estimation units 41-1 to 41-4 together with the inputs of the decoding units 42-1 to 42-n and individually correspond to these channel estimation units 41-1 to 41-4. Beam level detectors 43-1 to 43-4 having the above-mentioned structure; beam selector 44 cascade-connected to these level detectors 43-1 to 43-4; Multiplexing unit 45 having the output of the beam selecting unit 44 connected to the input-Modulating unit 46 cascade-connected to the multiplexing unit 45-Antenna duplexer that realizes both transmission and reception of the antenna 81 by the modulating unit 46 and the DFT unit 82 (H) 47 Hereinafter, the operation of the third embodiment of the present invention will be described with reference to FIG.

The level detecting section 43-C has a channel estimating section 4
Estimated value h1 ^ obtained by 1-C as described above_C, H2
^_C, H3 ^_C, H4 ^_CIndividual sum of squares Σh1 ^_C, Σh2 ^_C, Σ
h3 ^ _C, Σh4 ^_CIs calculated over all subchannels.
The beam selector 44 selects one of the four beams described above.
In descending order of sum of squares
Bees that identify the beams and show these identified beams
Output the system identification information.

The multiplexing section 45 multiplexes these beam identification information and the above-mentioned upstream transmission information, and also the modulator 46,
It transmits to the transmitting device 30 via the antenna duplexer 47 and the antenna 81. That is, the transmitting device 30 under the processing that the receiving device 40A takes the initiative in this way,
It is possible to specify a beam on which a suitable wireless transmission path is formed with the receiving device 40A which is the receiving end of the first transmission information or the second transmission information.

Therefore, transmitting apparatus 30 can maintain the transmission quality and service quality high by applying the beam to channel control and the like and optimally allocating the elements of the space-time coding matrix, for example. In addition,
In the present embodiment, the above-mentioned "beam in which a suitable wireless transmission path is formed" is specified on the assumption that the main lobes of the individual beams do not overlap each other.

However, for such a specific object, in addition to the sum of squares obtained for each beam or in place of these sums of squares, "combinations of beams forming sectors and radio zones that overlap each other" are used. The sum of squares of the estimated values obtained for each of them may be obtained, and the beam or the combination of the beams may have the maximum sum of squares.

Further, in each of the above-mentioned embodiments, there is no disclosure about the process of deriving the space-time coding matrix to be applied. However, the process of deriving such a space-time coding matrix is not a feature of the present invention, and the present invention is not limited to a known space-time coding matrix and will be derived in the future as long as the following conditions are satisfied. It is also possible to apply a new space-time coding matrix.

A desired transmission rate and real-time performance are achieved within the range of processing amount that can be secured at the transmitting end and the receiving end.・ The number of columns is "the number of transmission information to be multiplexed in the process of space-time encoding (not only the number of users who should be the source and destination, but all transmission information is logically based on the desired attribute. It may be the number of sets formed by being divided.) "Or more.

Further, in each of the above-mentioned embodiments, the IDF
The T units 77-1 to 77-4 are generated under the spreading process based on different spreading codes, and adders 76-11 to 76-1n, ...
A transmission wave signal is generated by performing an inverse discrete Fourier transform on a plurality of sub-channel signals combined by 76-41 to 76-4n and adding a guard interval.

However, the present invention is not limited to such a configuration. For example, when the number of wireless channels to be formed in parallel between the transmitting device 30 and the receiving devices 40 and 40A is small, addition is performed. Units 76-11 to 76-1n, ..., 76-41 to
76-4n may not be provided at all. Further, in each of the above-described embodiments, QPSK is applied as a primary modulation method performed by the modulators 72-1 and 72-2 according to the first transmission information and the second transmission information, respectively.

However, as far as the primary modulation method is concerned, any method is acceptable as long as it is compatible with the space-time coding, the pilot sequence multiplexing, the beam forming, the spreading processing and the inverse discrete Fourier transform which should be subsequently performed in symbol units. A modulation scheme may be applied. Furthermore, in each of the above-described embodiments, the size of the space-time coding matrix and the allocation of the elements of the space-time coding matrix are kept constant.

However, these sizes and allocations may be appropriately updated under the cooperation of the transmitting device 30 and the receiving devices 40 and 40A based on, for example, the procedure of channel control, etc. May be achieved. -Effective use of radio frequency-Optimization of zone configuration and channel allocation-Convenience and efficiency in maintenance and operation-Reduction of power consumption and other resources In addition, the MC-CDMA method is applied in each of the above-described embodiments. ing.

However, the present invention is not limited to such a configuration, and if the transmission rate per subcarrier is set low, the deterioration of transmission quality due to multipath can be reduced or avoided. A variety of multiple access schemes such as MT-CDMA or any desired multi-carrier modulation scheme may be applied. Furthermore, in each of the above-described embodiments, the transmission device 30 performs space-time coding prior to the spreading process.

However, the order in which the spreading process and the space-time coding should be performed are opposite as long as both are linear operations and the desired dynamic range and accuracy are secured in the process of the operations. May be. Further, in each of the above-described embodiments, the antennas 31-1 to 31-4 form four beams in parallel under the above-described phase-shift feeding.

However, the number of beams to be formed in this way may be any value as long as it is equal to or less than the number of columns of the space-time coding matrix used for space-time coding. Furthermore, in each of the above-described embodiments, a single spreading code is applied to the transmission of individual transmission information. However, the present invention is not limited to such a configuration, and for example, by applying a plurality of spreading codes in advance to the transmission of transmission information whose source or destination is a single user (subscriber), Either may be achieved.

Flexible adaptation to a wide range of changes in the amount of information transmitted. Flexible adaptation to a wide range of changes in the speed at which transmission information should be transmitted. Redundant wireless transmission between single or multiple receiving ends. Formation of Path In each of the above-described embodiments, the present invention is applied to the mobile communication system.

However, the present invention is not limited to such a mobile communication system, and if the desired transmission quality is achieved by applying the space-time coding method and the multi-carrier modulation method together, It can be applied to various transmission systems such as optical transmission systems. Furthermore, in each of the above-described embodiments, channel estimation is performed based on the correlation with the pilot sequence described above.

However, the present invention is not limited to such a configuration, and if means for separately performing such channel estimation is provided, the frequency arrangement and channel configuration to be applied to realize each channel estimation. , Zone configuration (sector configuration), channel control method, and other configurations may be arbitrary. Further, the present invention is not limited to the above-described embodiments, and within the scope of the present invention, various embodiments can be realized, and some or all of the constituent devices are improved. May be done.

Hereinafter, the configurations of the present invention disclosed in the above-described embodiments will be organized hierarchically and multilaterally, and will be listed as supplementary notes. (Supplementary Note 1) Space-time coding of transmission information based on a space-time coding matrix having columns of the number P or more of beams formed by the array antenna 10 to generate columns of space-time codes individually corresponding to these beams. The encoding means 11 and the space-time encoding means 11 over a phase shift amount individually adapted to feed the plurality of E elements included in the array antenna 10.
Generated by the array antenna 10 and corresponding to the beam to be formed by the array antenna 10, the columns of the individual space-time codes are phase-shifted in parallel to generate a plurality (≦ P · E) of the phase-shifted space-time symbols. Of the beam forming means 12-1 to 12-P and the beam forming means 12-1 to 12-P of the plurality P, and a sequence of phase-shifting space-time codes individually corresponding to the elements of the plurality E. A transmitting apparatus comprising: a plurality of E transmitting means 13-1 to 13-E for performing carrier modulation and transmitting in parallel via these elements. (Supplementary Note 2) Transmission information given as a bit string equal to the number P of beams formed by the array antenna 10 is parallel-processed over a phase shift amount individually adapted to feed a plurality of E elements included in the array antenna 10. Phase shift
A plurality of P beams forming means 12A-1 to 12A-P for generating a sequence of P phase-shifted transmission information and a plurality of P beams based on a space-time coding matrix having columns of P or more of the beams. Space-time coding means 11A for performing space-time coding on the columns of P phase-shifted transmission information generated by the forming means 12A-1 to 12A-P in parallel, and generating a sequence of space-time codes individually corresponding to these beams. And a plurality E of transmitting means 13A-1 to 13A-E for performing multicarrier modulation on the sequence of space-time codes generated by the space-time encoding means 11A and transmitting them in parallel via the plurality of E elements. A transmitting device characterized by the above. (Supplementary Note 3) In the transmission device according to Supplementary Note 1 or Supplementary Note 2, the transmission information is transmission information of a plurality of p that is equal to or less than the number P of beams to be formed by the array antenna 10. apparatus. (Supplementary Note 4) In the transmitting apparatus according to Supplementary Note 3, the space-time encoding means 11 and 11A are arranged such that the elements are allocated to these pieces of transmission information in a number that matches the ratio of the information amount of the plurality of pieces of transmission information. A transmitter, which performs space-time coding based on a coding matrix.

(Supplementary note 5) In the transmitting apparatus according to Supplementary note 3 or Supplementary note 4, when the allocation of the elements of the space-time coding matrix to the plurality of pieces of transmission information is to be updated, a notification to that effect is received. A transmission device comprising space-time encoding support means 14 for transmitting to an end.

(Supplementary Note 6) In the transmitting apparatus according to any one of Supplementary Notes 1 to 5, the transmitting means 13-1 to 13-E and 13A-1 to 13A-E of the plurality E are the multi-carriers. A transmitting apparatus, which performs a spreading process in a frequency domain for each sub-channel suitable for a modulation method.

(Supplementary Note 7) In the transmitting apparatus according to Supplementary Note 6, the transmitting means 13-1 to 13-E, 13A-1 of the plurality of Es.
13A to 13A-E multiplex sub-channel signals generated by frequency-domain spreading processing based on different spreading codes for each sub-channel.

(Supplementary Note 8) In the transmission device according to any one of Supplementary Notes 1 to 7, the space-time encoding means 1
1 and 11A perform space-time coding based on a space-time coding matrix in which the number of columns is adapted to the total amount of information of the transmission information.

(Supplementary Note 9) In the transmitting apparatus according to Supplementary Note 8, when the space-time encoding matrix applied to the space-time encoding is to be changed, a space-time code transmitting a notification indicating that fact to the receiving end. A transmission device comprising the conversion support means 14A. (Supplementary note 10) In the transmitting device according to any one of supplementary notes 1 to 9, the space-time encoding means 11, 11A.
Is characterized in that beam identification information individually corresponding to the beams to be formed by the array antenna 10 and having small cross-correlation and a small beam identification information is added to the space-time code sequence corresponding to the beam identification information. apparatus.

(Additional remark 11) In the transmitting apparatus according to any one of additional remarks 1 to 10, a radio signal which is notified by the receiving end and is formed individually between the array antenna 10 and the receiving end. The space-time encoding means 11, 11A for acquiring the transmission characteristics of the transmission path is provided, and the space-time encoding means 11, 11A are of the space-time encoding matrix used for space-time encoding of the transmission information to be transmitted to the receiving end. Of the elements,
A transmitting apparatus, wherein elements suitable for a combination of transmission characteristics acquired by the transmission characteristic acquiring means 15 are assigned to the receiving end.

(Supplementary Note 12) The array antenna is space-time coded and multi-carrier modulated based on a space-time coding matrix having columns of the number P or more of beams formed by the array antenna 20 installed at the transmitting end. Channel estimating means 22 for estimating the characteristics of P radio transmission paths formed in parallel between the separating means 21 for separating the received wave coming from 20 for each sub-channel component and the antenna array 20- 1 to 22-P, the space-time coding matrix,
Decoding for space-time decoding the components of the individual sub-channels separated from the received wave by the separating unit 21 based on the characteristics estimated by the channel estimating units 22-1 to 22-P to restore the transmission information. And a conversion unit 23. (Supplementary Note 13) In the receiving device according to Supplementary Note 12, beam identification information individually indicating a beam formed by the array antenna 20 is multiplexed on the received wave.
The channel estimation means 22-1 to 22-P are based on the correlation between the component of each sub-channel separated from the received wave by the separation means 21 and the beam identification information individually indicating the beam of the number P. A receiving device for estimating characteristics of P wireless transmission lines formed in parallel with the antenna array 20. (Supplementary Note 14) In the receiving device according to Supplementary Note 12 or Supplementary Note 13, the received wave is generated under a spreading process in a frequency domain, and the decoding unit 23 applies the spreading process to a result of the space-time decoding. A receiving apparatus, which restores the transmission information by performing a matching despreading process.

(Supplementary Note 15) In the receiving apparatus according to any one of Supplementary Notes 12 to 14, among the beams formed by the array antenna 20, the beam is estimated by the channel estimating means 22-1 to 22-P. A receiving device comprising a notifying unit 24 for notifying the transmitting end of a single beam or a plurality of beams corresponding to the descending order of transmission quality achieved based on the characteristics of the P wireless transmission paths.

[0104]

As described above, in the inventions according to claims 1, 2 and 4, transmission diversity is surely achieved along with the formation of a desired sector or radio zone. Further, in the invention according to claim 3, even when the number of pieces of transmission information to be transmitted in parallel increases or decreases or is large, the maximum multiplexing degree of the multiplexing process to be performed after the space-time coding is performed. Is suppressed to a small value. Further, in the invention according to the fifth aspect, the precision of the space-time decoding is stably maintained high even when the characteristics of the transmission line may change from moment to moment.

In the invention of the subordinate concept of the third aspect of the invention, the transmission quality and the real-time property are maintained high. Further, in the first invention related to the invention described in claim 3,
The flexibility of adaptation to various maintenance and operation needs is enhanced. Further, in the first invention related to the invention described in claims 1 to 3, and the invention of the subordinate concept of the invention described in claim 4 or 5, transmission information to be transmitted in parallel The quality of service is maintained high even if the amount of information in the field can vary widely.

Further, in the second invention related to the invention described in claims 1 to 3, the quality of service is high even when the amount of transmission information to be transmitted in parallel is extremely large. Maintained. Further, in the third invention related to the invention described in claims 1 to 3, the space-time coding matrix applied to the space-time coding, and the transmission information to which each element of the space-time coding matrix is allocated, As long as the reception end can be identified, a high transmission quality based on the transmission diversity and a desired wireless zone (sector) can be achieved regardless of the number of pieces of transmission information.

Further, in the fourth invention related to the inventions described in claims 1 to 3, in the case where the number of transmission information to be transmitted in parallel, the amount of information, the speed and other attributes can change. Even if there is, a high transmission quality based on transmission diversity and a desired wireless zone (sector) are combined and stably maintained. Further, in the fifth invention related to the invention described in claims 1 to 3, the accuracy of the space-time decoding performed based on the result of the channel estimation at the receiving end is:
Even if the characteristics of the transmission line can change from moment to moment, it is stably maintained high.

Further, in the sixth invention related to the invention described in claims 1 to 3, the transmission information is addressed to the receiving end while performing space-time coding adapted to the change of the transmission characteristic of the transmission path. It is transmitted sequentially. Further, claim 4 or claim 5
In the invention related to the invention described in (1), the amount of processing to be secured at the transmitting end does not increase significantly, and the gain based on the transmission diversity is increased, and the interference based on the desired radio zone (sector) is suppressed. Is realized.

Therefore, in the wireless transmission system to which these inventions are applied, resources are efficiently used, and high transmission quality and service quality are achieved while being flexibly adapted to various configurations and scales. .

[Brief description of drawings]

FIG. 1 is a first principle block diagram of a transmission device according to the present invention.

FIG. 2 is a second principle block diagram of a transmission device according to the present invention.

FIG. 3 is a principle block diagram of a receiver according to the present invention.

FIG. 4 is a diagram showing first to third embodiments of the present invention.

FIG. 5 is a diagram showing characteristics of multi-beams formed by an antenna.

FIG. 6 is a diagram showing a structure of a frame.

FIG. 7 is a diagram showing a configuration example of a wireless transmission system to which MC-CDMA and space-time coding are applied.

[Explanation of symbols]

10, 20 array antenna 11, 11A space-time encoding means 12,12A beam forming means 13, 13A transmission means 14,14A space-time coding support means 15 Transmission characteristic acquisition means 21 Separation means 22 channel estimation means 23 Decoding means 24 Notification means 30,70 transmitter 31,71,81 antenna 32,73 space-time coding unit 33,74 Multiple access 34 Beam forming unit 35 Multiplexer (MUX) 40, 40A, 80 receiver 41,83 Channel estimation unit 42,84 Decoding unit (DEC) 43 Level detector 44 Beam selector 45 Multiplexer 46 Modulator 47 Antenna duplexer (H) 72 Modulator (MOD) 75 Diffuser 76 Adder (Σ) 77 IDFT Department 82 DFT section 85 despreader 86 signal judge

Claims (5)

[Claims] 1. A space-time code in which transmission information is space-time coded based on a space-time coding matrix having columns of number P or more of beams formed by an array antenna, and columns of space-time codes individually corresponding to these beams are generated. Encoding means and an individual corresponding to a beam to be formed by the space-time encoding means and formed by the array antenna over a phase shift amount individually adapted to feed a plurality of E elements of the array antenna. A plurality of P beam forming means for generating a plurality (≦ P · E) of phase-shifting space-time code rows in parallel, and a plurality of P beam forming means, A transmission means comprising a plurality of E transmitting means for performing multi-carrier modulation on a sequence of phase-shifting space-time codes individually corresponding to the plurality of E elements and transmitting them in parallel via these elements. Apparatus. 2. The transmission information provided as a bit string equal to the number P of beams formed by the array antenna in parallel over a phase shift amount individually adapted to feed a plurality of E elements included in the array antenna. A plurality of P beam forming means for phase-shifting and generating a sequence of P phase-shifted transmission information, and a plurality of P beam forming means based on a space-time coding matrix having columns of P or more beams. Space-time coding means for space-time coding the generated P pieces of phase-shifted transmission information in parallel and generating a space-time code string individually corresponding to these beams; and the space-time coding means. A transmitting device, comprising: a plurality of E transmitting means for performing multicarrier modulation on a space-time code sequence and transmitting in parallel via the plurality of E elements. 3. The transmission device according to claim 1, wherein the transmission information is a plurality of p transmission information items that are equal to or less than the number P of beams to be formed by the array antenna. Transmitting device. 4. Space-time coded based on a space-time coding matrix having columns of the number P or more of beams formed by an array antenna installed at a transmission end, and multicarrier-modulated to arrive from the array antenna. Separation means for separating the received wave for each sub-channel component; channel estimation means for estimating the characteristics of P wireless transmission paths formed in parallel with the antenna array; and the space-time coding matrix. And a decoding unit for performing space-time decoding of the components of the individual sub-channels separated from the received wave by the separating unit based on the characteristics estimated by the channel estimating unit to restore transmission information. A receiver characterized by. 5. The receiving device according to claim 4, wherein the received wave is multiplexed with beam identification information individually indicating a beam formed by the array antenna, and the channel estimation unit is the separation unit. Based on the correlation between the components of the individual sub-channels separated from the received wave by the beam identification information individually indicating the beams of the number P, the P number of P beams formed in parallel with the antenna array are A receiver for estimating the characteristics of a wireless transmission path.