JP3622883B2 - Array response simulator - Google Patents

Description

で与えられる。但し、ｚ_ｄ ^ｊ （ｔ） は参照点が受信する希望波の第ｊパス成分、ｚ_ｕ ^ｍｋ（ｔ） は参照点が受信する第ｍ干渉波の第ｋパス成分で、それぞれ
ｚ_ｄ ^ｊ （ｔ） ＝ｚ_ｄｆ ^ｊ （ｔ） ｚ_Ｄ （ｔ） （６）
ｚ_ｕ ^ｍｋ（ｔ） ＝ｚ_ｕｆ ^ｍｋ（ｔ） ｚ_Ｕ ^ｍ （ｔ） （７）
となる。ここで、ｚ_ｄｆ ^ｊ （ｔ） は希望波の第ｊパス成分の複素振幅、ｚ_Ｄ （ｔ） は希望波の送信シンボル波形、ｚ_ｕｆ ^ｍｋ（ｔ） は第ｍ干渉波の第ｋパス成分の複素振幅、ｚ_Ｕ ^ｍ （ｔ） は第ｍ干渉波の送信シンボル波形である。また、ｚ_ｇ （ｔ） は雑音ベクトルで
ｚ_ｇ （ｔ） ＝〔ｚ_ｇ１（ｔ） ｚ_ｇ２（ｔ） ・・・ｚ_ｇＮ（ｔ） 〕^ｔ （８）
であり、ｚ_ｇｉ（ｔ） は第ｉ素子に加えられる雑音である。ｚ_ｇｉ（ｔ） は互いに独立なゼロ平均のガウス変数であり、
＜ｚ_ｇ （ｔ） ＞＝０ （９）
＜ｚ_ｇ ^＊ （ｔ）ｚ_ｇ ^ｔ （ｔ） ＞＝σ_ｇ ^２ Ｉ_Ｎ （１０）
となる。但し、Ｉ_Ｎ はＮ次の単位行列である。また、σ_ｇ ^２ は雑音電力である。
【００１０】
以上の説明から、アレーレスポンスシミュレータは式（５）で表現されるプロセスを実時間実行する装置であればよいことがわかる。これは、図２に示す構成で実現できる。即ち制御部（ＣＯＮＴ）１１はシミュレータ全体の動作を制御し、以下に説明する各部の動作は制御部１１が発生する制御情報ＣＯＮＴ−ＩＮＦによって制御される。入力端子１２ｊから希望波の第ｊパス（ｊ＝１〜Ｌ_d ）の受信信号入力Ｄ_j が入力され、入力端子１３_nkより第ｍ干渉波の第ｋパス（ｍ＝１〜Ｍ、ｋ＝１〜Ｌ_um）の受信信号入力Ｉ_mkが入力され、これらの入射角は制御部１１から制御情報ＣＯＮＴ−ＩＮＦとしてアレーレスポンス形成部にそれぞれ入力される。つまり入力端子１４ｊから希望波の第ｊパスの入射角入力Ａ−Ｄ−ｊが入力される入力端子１２ｊの希望波の受信信号入力Ｄ−ｊと、入力端子１４ｊの入射角入力Ａ−Ｄ−ｊが希望波の第ｊパスのアレーレスポンス形成部ＡＲ−Ｄ−ｊに入力される。また、入力端子１５_mkより第ｍ干渉波の第ｋパスの入射角入力が入力され、入力端子１３_mkからの第ｍ干渉波受信信号Ｉ−ｍ−ｋが、入力端子１５_mkから第ｍ干渉波の入射角が第ｍ干渉波の第ｋパスのアレーレスポンス形成部ＡＲ−Ｉ−ｍ−ｋに入力される。
【００１１】
各アレーレスポンス形成部ＡＲ−Ｄ−ｊ，ＡＲ−Ｉ−ｍ−ｋの各出力は、アンテナエレメント数に相当するＮ個の要素からなるベクトルであり、アレーレスポンス形成部ＡＲ−Ｄ−ｊから希望波の第ｊパスのアレー出力ベクトルＡＯＤ−ｊが出力され、アレーレスポンス形成部ＡＲ−Ｉ−ｍ−ｋから第ｍ干渉波の第ｋパスのアレー出力ベクトルＡＯ−Ｉ−ｍ−ｋが出力される。これらの出力ベクトルは全て（エレメント毎に）加算器１６_j1〜１６_jN，１７_m1〜１７ _mNで複素加算され、さらに雑音ベクトル加算器１８₁ 〜１８_N で複素加算される。また第ｉエレメント（ｉ＝１〜Ｎ）に雑音発生器でＮ−ｉからの雑音が加算器１８_i で加算される。雑音ベクトルと複素加算されたアレー出力ベクトルはアレーレスポンスシミュレータ全体の出力Ｏｕｔとなる。
【００１２】
アレーレスポンス形成部の構成例を図３に示す。上述のように、アレーレスポンス形成部の入力は、希望波Ｄ−ｊ又は干渉波のパス成分Ｉ−ｍ−ｋと、入射角情報Ａ−Ｄ−ｊ又はＡ−Ｉ−ｍ−ｋである。アレーレスポンス形成部はＮ個のアンテナ素子に相当するＮ個の要素で構成される。それらは式（３）に対応したＮ個の複素振幅の発生回路Ｅ−１〜Ｅ−ＮとＮ個の複素乗算器Ｍ−１〜Ｍ−Ｎから構成される。第ｉ番目の複素振幅の発生回路Ｅ−ｉでは、受信信号の入射角に対応したアレーレスポンスに対応する複素振幅ａ_ｉ （θ）を発生する（上述のように、ａ_ｉ （θ）はアレーの形状によって異なる。リニアアレーの場合のａ_ｉ （θ）は式（３）、（４）で与えられる）。複素振幅ａ_ｉ （θ）は入力信号に複素乗算されて出力（ＡＯ−Ｄ−ｊ又はＡＲＯ−Ｉ−ｍ−ｋ）となる。
【００１３】
【発明の効果】
以上、説明したようにこの発明によると、実際に空間にアンテナ素子を配置しなくても各入力信号の入射角に対応したアレーレスポンスベクトルが発生できる。出力にはこれらの合成信号が得られるから、このシミュレータの出力をサンプリングすればスナップショットベクトルが得られる。種々のアダプティブアレーアンテナのアルゴリズムや指向性パターン制御アルゴリズムは、このスナップショットベクトルを入力とする。従って、このシミュレータ装置に実際の使用条件（シンボルレートやフレーム構成、等）に合わせた信号を入力し、シミュレータ出力に上記のアルゴリズムを実行する装置を接続して全系を動作させれば、実際の環境に近い条件下での評価や試験が可能となる。
【００１４】
また、移動通信電波伝搬環境における受信信号に対するアレーレスポンスを総合的に模擬するためには、図４に示すようにフェージング伝搬路を模擬するフェージングシミュレータ、つまり希望波送信波形Ｄが入力され、第ｊパスを通った希望波Ｄ_j （ｊ＝１・・・Ｌｄ）を出力する希望波フェージングシミュレータＦＳ−Ｄ−１と、第ｍ干渉波送信波形Ｉ−ｍが入力され、それぞれ、第ｋパスを通った干渉波Ｉ−ｍ−ｋ（ｍ＝１，・・・，Ｍ、ｋ＝１，・・・，Ｌ_uM）をそれぞれ出力する干渉波フェージングシミュレータＦＳ−Ｉ−ｍとを用い、これら各フェージングシミュレータの出力を、各パスごとに図２に示したこの発明のアレーレスポンスシミュレータの、対応するアレーレスポンス形成部ＡＲ−Ｄ−ｊ，ＡＲ−Ｉ−ｍ−ｋの各対応入力端子に供給すればよい。この場合、上記の実際の使用条件に合わせた信号をフェージングシミュレータに入力されることは言うまでもない。
【図面の簡単な説明】
【図１】Ｎ素子リニアアレーのアンテナ素子配置を示す図。
【図２】この発明に基づくアレーレスポンスシミュレータの実施例の機能構成を示すブロック図。
【図３】アレーレスポンス形成部の一機能的構成例を示すブロック図。
【図４】フェージング伝搬路を模擬するフェージングシミュレータをこの発明のアレーレスポンスシミュレータに接続する場合の一機能的構成例を示すブロック図。[0001]
BACKGROUND OF THE INVENTION
The present invention is used to develop, evaluate, and test a signal processing apparatus for an adaptive array antenna, a beam tracking antenna, and the like, and gives each incident angle of a received signal as a parameter without actually arranging the antenna. The present invention relates to a vector channel simulator that outputs a vector in which complex amplitudes in which a change in relative phase similar to that in a case where antenna elements are arranged in space are applied to a reception signal of each antenna element are arranged.
[0002]
[Prior art]
A feature of mobile communication is that the wireless propagation environment is a multipath propagation path. Considering an upstream (mobile station transmission, base station reception) communication path, a bundle of transmitted elementary waves affected by scattering, diffraction, and reflection around the mobile station is reflected directly or further after being reflected far away. Arrives at the base station. Therefore, in the base station, the transmission signal of the mobile station is received through each path divided into a plurality of components having different angles of arrival. These components corresponding to each path are composed of the bundle of transmitted elementary waves described above, and the process of creating this bundle (scattering, diffraction, reflection, etc.) is different for each path, so each path is an independent fading. Will be receiving.
[0003]
Recently, the effectiveness of an adaptive array antenna in such a mobile communication environment has been pointed out. That is, it can be expected that the effective use of the interference cancellation capability of the adaptive array antenna can improve the surface utilization efficiency of the same frequency, and the equalizer can be made unnecessary by the delayed wave removal capability.
Technical issues in the development of adaptive array antennas are broadly divided into hardware issues such as antenna element configuration methods and radio frequency band circuit configurations, and algorithms issues such as antenna beam control and interference cancellation. Of course, since the characteristics of the two influence each other, it is needless to say that ultimately an optimum design that takes both into account is necessary. However, both are technologies that belong to individual fields, and in one examination process, the other is often modeled and handled. In algorithm development, evaluation, and testing, it is often assumed that antenna elements and radio frequency circuits operate ideally, and that signals are represented and simulated using complex baseband representations. It is.
[0004]
Naturally, various algorithms will eventually operate in real time, so the algorithms are executed on a device that matches the actual usage conditions (symbol rate, frame configuration, etc.), and the expected channel (antenna It is necessary to evaluate in an environment that can be assumed in reality by connecting to a device that simulates the environment of the device and the radio frequency band circuit). An adaptive array antenna controls its directivity pattern by weighting and combining a plurality of antenna element outputs. Since each antenna element is spatially separated, the phase of the received signal (or complex amplitude in the complex baseband representation) differs for each antenna element, and the relative change between each element is the incident angle of the received signal. (A vector in which complex amplitudes of received signals at each antenna element are arranged is called an array response). This means that if the shape of the array antenna and the incident angle of each received signal (each multipath component of the desired wave and each multipath component of the interference wave) are given, the array response to them can be simulated in the complex baseband. means. However, such an array response simulator is not known.
[0005]
[Problems to be solved by the invention]
The present invention provides an array response simulator that enables algorithm development, evaluation, and testing of an adaptive array antenna. By inputting the array shape (including the number of elements) and the incident angle of each received signal as parameters, an array response corresponding to them is generated. As a result, a change in relative phase similar to the case where the antenna elements are arranged in space is generated in each received signal.
[0006]
[Means for Solving the Problems]
According to the present invention, the complex amplitude is generated by the complex amplitude generating means for each element of the array antenna in accordance with the given incident angle, and the complex amplitude for the incident angle is obtained for the received signal at each element of the array antenna. Complex multiplication is performed by multiplication means, and the multiplication results are added by addition means for each antenna element to simulate array responses to a plurality of received signals of the array antenna.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
First, the principle of the present invention will be described, and then embodiments will be described.
When the shape of the array is given and the signal received by the reference point (arbitrary) is z _r (t), the signal z _i (t) (i = 1 to N) received by the i-th element is
z _i (t) = a _i (θ) z _r (t) (1)
It is represented by Here, a _i (θ) is an array response, which is given as a function of the relative angle θ between the direction of arrival of the signal and the coordinates (arbitrary) on the array. Further, a vector (a) (a ₁ (θ) a ₂ (θ)... A _N (θ)] ^t (2) in which a _i (θ) are arranged.
Is called an array response vector. t represents the transpose of the vector.
[0008]
If the signal bandwidth is narrower than the coherent bandwidth of the channel, a _i (θ) is expressed as the amount of phase change associated with the distance difference between the reference point and each element,
a _i (θ) = exp {jψ _i (θ)} (3)
It becomes. For example, in the case of a linear array in which N elements EL-1 to EL-N as shown in FIG. 1 are arranged on a straight line at intervals d, ψ _i (θ) = (2π / λ) if the reference point is the first element. ) ( I- 1) d sinθ (4)
It becomes. Where λ is the carrier wavelength and d is the element spacing.
[0009]
Received desired wave is divided into L _d pieces of the path, the j-th path components is assumed to come from the direction of theta _j in array. Further, the m-th present are M interference source is received is divided into L _um number of paths, further its k th path component shall arriving from the direction of theta _k in the array. At this time, the combined received signal vector z (t) is

Given in. Here, z _d ^j (t) is the j-th path component of the desired wave received by the reference point, z _u ^mk (t) is the k-th path component of the m-th interference wave received by the reference point, and z _d ^j ( t) = z _df ^j (t) z _D (t) (6)
z _u ^mk (t) = z _uf ^mk (t) z _U ^m (t) (7)
It becomes. Here, z _df ^j (t) is the complex amplitude of the j-th path component of the desired wave, z _D (t) is the transmission symbol waveform of the desired wave, and z _uf ^mk (t) is the k-th path component of the m-th interference wave. , Z _U ^m (t) is a transmission symbol waveform of the m-th interference wave. Z _g (t) is a noise vector and z _g (t) = [z _g1 (t) z _g2 (t)... Z _gN (t)] ^t (8)
Z _gi (t) is noise added to the i-th element. z _gi (t) are mutually independent zero-mean Gaussian variables,
<Z _g (t)> = 0 (9)
<Z _g ^* (t) z _g ^t (t)> = σ _g ² I _N (10)
It becomes. Here, _IN is an Nth-order unit matrix. Σ _g ² is noise power.
[0010]
From the above description, it can be understood that the array response simulator may be any device that executes the process expressed by Equation (5) in real time. This can be realized by the configuration shown in FIG. That is, the control unit (CONT) 11 controls the operation of the entire simulator, and the operation of each unit described below is controlled by control information CONT-INF generated by the control unit 11. Received signal input D _j of the j-th path of the desired wave from the input terminal 12j (j = 1~L _d) is input, the k paths of the m interference wave from an input terminal _{13 nk (m = 1~M, k} = 1 to L _um ) received signal inputs I _mk are input, and these incident angles are input from the control unit 11 to the array response forming unit as control information CONT-INF. That the reception signal input D-j of the desired wave of the input terminal 12j incident angle input A -D-j of the j-path of the desired wave from the input terminal 14j is input, the incident angle of the input terminal 14j inputs A-D- j is input to the array response forming unit AR-D-j of the jth pass of the desired wave. Further, the incident angle input of the k paths of the m interference wave from the input terminal 15 _mk is input, the m interference wave receiving signal I-mk from the input terminal 13 _mk is the m interference from the input terminal 15 _mk The incident angle of the wave is input to the array response forming unit AR-Imk of the kth path of the mth interference wave.
[0011]
Each output of each array response forming unit AR-Dj, AR-Im-k is a vector composed of N elements corresponding to the number of antenna elements, and is requested from the array response forming unit AR-Dj. An array output vector AOD-j of the j-th path of the wave is output, and an array output vector AO-Im-k of the k-th path of the m-th interference wave is output from the array response forming unit AR-Im-k. The All of these output vectors are complex-added by adders 16 _{j1 to} 16 _jN and 17 _m1 to 17 _mN (for each element), and further complex-added by noise vector adders 18 ₁ to 18 _N. Further, the noise from the N-i is added to the i-th element (i = 1 to N) by the adder 18 _i by the noise generator. The array output vector complex-added with the noise vector becomes the output Out of the entire array response simulator.
[0012]
A configuration example of the array response forming unit is shown in FIG. As described above, the input of the array response forming unit is the desired wave Dj or the path component Imk of the interference wave, and the incident angle information ADj or AImk. The array response forming unit is composed of N elements corresponding to N antenna elements. They are composed of N complex amplitude generation circuits E-1 to EN corresponding to the equation (3) and N complex multipliers M-1 to MN. The i-th complex amplitude generation circuit E-i generates a complex amplitude a _i (θ) corresponding to an array response corresponding to the incident angle of the received signal (as described above, a _i (θ) is an array). (A _i (θ) in the case of a linear array is given by equations (3) and (4)). The complex amplitude a _i (θ) is complex-multiplied to the input signal to become an output (AO-Dj or ARO-Imk).
[0013]
【The invention's effect】
As described above, according to the present invention, an array response vector corresponding to the incident angle of each input signal can be generated without actually arranging antenna elements in space. Since these synthesized signals are obtained at the output, a snapshot vector can be obtained by sampling the output of the simulator. Various adaptive array antenna algorithms and directivity pattern control algorithms receive this snapshot vector as an input. Therefore, if a signal that matches the actual usage conditions (symbol rate, frame configuration, etc.) is input to this simulator device, and the device that executes the above algorithm is connected to the simulator output, the entire system is operated. It is possible to evaluate and test under conditions close to the environment.
[0014]
Further, in order to comprehensively simulate an array response to a received signal in a mobile communication radio wave propagation environment, a fading simulator that simulates a fading propagation path, that is, a desired wave transmission waveform D is input as shown in FIG. A desired wave fading simulator FS-D-1 that outputs a desired wave D _j (j = 1... Ld) that has passed through the path and an m-th interference wave transmission waveform Im are input. The interference wave fading simulator FS-I-m that outputs the _passed interference wave _Imk (m = 1,..., M, k = 1,..., L _uM ) respectively. The output of the fading simulator is obtained for each pair of corresponding array response forming units AR-Dj and AR-Imk of the array response simulator of the present invention shown in FIG. It may be supplied to the input terminal. In this case, it goes without saying that a signal that matches the actual use condition is input to the fading simulator.
[Brief description of the drawings]
FIG. 1 is a diagram showing an antenna element arrangement of an N element linear array.
FIG. 2 is a block diagram showing a functional configuration of an embodiment of an array response simulator according to the present invention.
FIG. 3 is a block diagram illustrating a functional configuration example of an array response forming unit.
FIG. 4 is a block diagram showing an example of a functional configuration when a fading simulator that simulates a fading propagation path is connected to the array response simulator of the present invention.

Claims (1)

In an array response simulator that simulates changes in relative phase similar to when array antenna elements are arranged in space without arranging each antenna element,
Each path component of the desired wave signal and its incident angle information are input, and a plurality of desired wave array response forming units each outputting N vectors of antenna elements,
Each path component of the interference wave signal and the incident angle information thereof are input, and a plurality of interference wave array response forming units each outputting N vectors of antenna elements,
Each of the array response forming units receives each input incident angle information, and N complex amplitude generating circuits for generating a complex amplitude corresponding to the array response corresponding to the incident angle of the received signal for each antenna element; N complex multipliers for multiplying the generated complex amplitude and the input path component to output the vector respectively.
Adding means for adding output vectors for each corresponding antenna element of the array response forming unit of the desired wave and the array response forming unit of the interference wave and outputting a reception signal of the N antenna elements;
An array response simulator for simulating array responses to a plurality of received signals of an array antenna.

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