JP5712850B2 - Synchronous code detection method and apparatus - Google Patents

Description

  The present invention relates generally to the communications field. More specifically, the present invention relates to a method and an apparatus for detecting a synchronization code (Synchronization symbol, SS) from a received signal in a TDD system, particularly a TDD-LTE (Time Division Duplex-Long Term Evolution) system.

In a wireless communication system, the damping effect of the radio channel, which may greatly wave over wide oscillation received signal. In order to ensure accuracy after signal quantization, the terminal typically needs to dynamically track changes in the signal using an automatic gain control unit. Based on the operating range of the analog-digital converter (ADC), the gain of the amplifier is increased when the received signal is weak, and the gain of the amplifier is decreased when the received signal is too strong. In order to ensure that the adjustment of the gain of the amplifier does not add distortion to the received signal, the AGC measurement and adjustment needs to be performed based on the frame structure of the received signal. The adjustment of AGC has a great influence on the quality of the synchronization detection performed in the synchronization process between the terminal and the base station.

  In a 3GPP Long Term Evolution (LTE) system, there are a time division duplex (TDD) mode and a frequency division duplex (FDD) mode. In the frequency division duplex mode, uplink / downlink signals are transmitted at different frequency points, while in the time division duplex mode, uplink / downlink signals are transmitted in different time zones of the same carrier frequency.

In a time division duplex mode LTE (TDD-LTE) system, the received signal correlates with the time domain of the local synchronization code, thereby realizing synchronization and cell synchronization code type acquisition. Therefore, in application, after receiving a signal, it is necessary to detect a synchronization code from the received signal. In the TDD-LTE system, there are seven types of frame structure arrangements shown in Table 1. In Table 1, “D” indicates a downlink subframe, “U” indicates an uplink subframe, and “S” indicates a special subframe. Each subframe has a length of 1 ms and is composed of two slots having a length of 0.5 ms. As shown in Table 1, the primary synchronization code (Primary synchronization symbol, PSS) is located in a subframe having subframe numbers 1 and 6, and the secondary synchronization code (Secondary synchronization symbol, SSS) is a subframe number. Are located in subframes with 0 and 5. FIG. 10 shows a TDD frame structure of half subframes. Of these, the subframe SF # 1 (subframe number 1) is a special subframe, and includes a downlink time slot DwPTS, an uplink / downlink conversion interval GP, and an uplink time slot UpPTS. In FIG. 10, PSS is located in the third code of the downlink time slot DwPTS, while SSS is located in the last code of subframe SF # 0 (number 0 subframe). In the cell search, the frame timing and the cell ID are acquired by using detection for these two synchronization codes.

（ｋ ＝ ０， １， …， ６１）であり，合計３つがある。

ただし、

は｛２５，２９，３４｝のうちの一つである。図１１は、キャリアにおいてＰＳＳを調整することを示している。図１１に示されたように、当該系列がＤＣを中心に左右各３１個のサブキャリアに位置し、ＤＣサブキャリアに対応する

が０に設定される。系列の両側における五個のサブキャリアも同様に０に設定する。合計７２個のサブキャリアは中心の六個のＲＢ （ｒｅｓｏｕｒｃｅ ｂｌｏｃｋ、リソースブロック）に対応する。サブフレームＳＦ＃１及びサブフレームＳＦ＃６におけるＰＳＳ系列は同様のものである。 The PSS is a Zadoff-Chu sequence with a length of 62

(K = 0, 1,... 61), and there are three in total.

However,

Is one of {25, 29, 34}. FIG. 11 shows adjusting the PSS in the carrier. As shown in FIG. 11, the sequence is located in 31 left and right subcarriers around DC and corresponds to the DC subcarrier.

Is set to 0. The five subcarriers on both sides of the sequence are also set to 0. A total of 72 subcarriers correspond to the six central RBs (resource blocks). The PSS sequences in subframe SF # 1 and subframe SF # 6 are the same.

  For detection of PSS, a detection method based on matching filtering is usually adopted. If the timing is unknown, it is necessary to detect the position of the PSS by searching for at least 5 ms.

The SSS is a series formed by m series d (2k) and d (2k + 1) having two lengths of 31, and has a total of 168 series. FIG. 12 shows adjusting the SSS in the carrier. As shown in FIG. 12, the SSS occupies six RBs centered on the carrier, like the PSS, and each of the five subcarriers on both sides of the sequence is set to zero. The difference is that the SSS sequences located in subframe SF # 0 and subframe SF # 5 are different.

  Refer to 3GPP 36.211 for a specific method of generating a sequence. Detailed description is omitted here.

  The SSS detection method is usually based on code sequence matching detection in the frequency domain. When the CP (cyclic prefix) type is unknown, it is necessary to blindly detect the CP type with SSS as necessary.

  In the initial network access or switching period, the terminal performs synchronization code detection to acquire timing information so as to establish time and frequency synchronization with the base station. After the terminal obtains the timing information, the gain value of the AGC unit can be adjusted with an integer number of subframes or full frames as an interval based on the frame structure. On the other hand, when the terminal does not acquire timing information, AGC measurement and adjustment cannot be adjusted in units of code boundaries, and different gains are used in the synchronization code. If such adjustment occurs in the synchronization code, for example, if it occurs in the PSS as shown in FIG. 13, or occurs in the SSS as shown in FIG. 14, the difference in the PSS or SSS. A large amplifier gain is used, which can reduce the accuracy of sync code detection. On the other hand, the independence between signals, for example, the conversion intervals of the upstream signal, downstream signal, and upstream / downstream signal of the TDD system are independent, so that the amplifier gain specified by a certain type of signal is different from that of the other type. When used on a signal, the signal may be de-amplified, reducing the quality of subsequent synchronization detection. As shown in FIG. 15, the gain value obtained from the uplink signal may be used in the downlink signal due to an unknown cause for the signal load or an unknown cause for the uplink / downlink, The gain value determined by the signal at the guard interval may be used during the downlink signal. Since only the noise signal exists in the protection interval and the intensity is very low, the gain value thus obtained becomes high. On the other hand, when the downlink signal is strong, the power of the subsequent downlink signal may be significantly improved as indicated by the upward arrow in FIG. In particular, when the period of AGC adjustment is small, there is a possibility that there is a large difference between the strength of the PSS signal and the strength of the previous downlink signal. Such differences will affect PSS detection and frame synchronization acquisition.

  The following provides a basic understanding of some aspects of the present invention by providing a brief overview of the present invention. It should be understood that this summary is not exhaustive of the invention. To that end, it is not intended to define an essential or important part of the invention, nor is it intended to limit the scope of the invention, and provides some concepts in a simplified form to be described in more detail below. It is not limited to the preceding explanation.

In view of the problems existing in the above-described prior art, the synchronization code detecting apparatus and method provided by the embodiments of the present invention is based on the difference between the current AGC gain obtained from the AGC unit and the predetermined target gain. by compensating the AGC gain changes on the down-sampled signal of obtaining a stable sample signal amplitude after. For each signal whose gain has been compensated, normalization is performed for each sample point using each normalization window centered on each sample point of the signal, thereby further stabilizing the signal. Thereafter, synchronization detection is performed using the normalized signal.

According to an embodiment of the present invention, in a TDD communication system, an apparatus for detecting a synchronization code from a signal output from an automatic gain control AGC unit,
To obtain a stable sample signal width vibration by compensating the AGC gain variation on the down sampled signal after AD conversion based on the difference between the current AGC gain and a predetermined target gain obtained from the AGC unit A compensation unit to be arranged; and
For each sample point of the compensated sample signal, the normalized signal is normalized by using the statistics of all the sample points within the corresponding normalization window centered on that sample point. A pre-processing unit arranged to obtain,
A synchronization code detection unit arranged to perform synchronization code detection on the normalized signal to identify the position and type of the synchronization code in the normalized signal;
An apparatus is provided.

According to another aspect of the present invention, a method for detecting a synchronization code from a signal output from an automatic gain control AGC unit in a TDD communication system, comprising:
Based on the difference between the current AGC gain and a predetermined target gain obtained from the AGC unit, it obtains a stable sample signal width vibration by compensating the AGC gain changes on the down-sampled signal after AD change,
For each sample point of the compensated sample signal, the normalized signal is normalized by using the statistics of all the sample points within the corresponding normalization window centered on that sample point. Acquired,
A method is provided that includes performing synchronization code detection on the normalized signal to determine the position and type of the synchronization code in the normalized signal.

3 is a flowchart illustrating a method for detecting a synchronization code from signals output from an AGC unit in a TDD system according to an embodiment of the present invention. FIG. 3 is a structural diagram illustrating an AGC unit according to an embodiment of the present invention. It is a figure which shows one specific example of the process of step S110 shown by FIG. It is a figure which shows one specific example of the process of step S120 shown by FIG. It is a figure which shows one specific example of the process of step S426 shown by FIG. FIG. 6 is a comparison diagram showing correlation peaks of PSS obtained by PSS detection when preliminary processing has been performed on AGC gain change in the PSS code and signals that have not been subjected to preliminary processing. It is a figure which shows the apparatus which detects a synchronous code from the signals output from the AGC unit in the TDD system of one Example by this invention. It is a figure which shows one specific example of the compensation unit 710 shown by FIG. FIG. 8 is a diagram illustrating a specific example of a preliminary processing unit 720 illustrated in FIG. 7. It is a figure which shows the frame structure figure in a TDD-LTE system. It is a figure which shows the PSS modulation | alteration figure in a TDD-LTE system. It is a figure which shows the SSS modulation diagram in a TDD-LTE system. It is a figure which shows the AGC gain change in a PSS signal. It is a figure which shows the AGC gain change in a SSS signal. It is a figure which shows the condition of the change of the signal power by AGC gain change. FIG. 6 is a block diagram illustrating an exemplary structure of a general purpose computer capable of implementing methods and / or apparatus according to embodiments of the invention.

According to the present invention, by performing the pretreatment with respect to signal the automatic gain control has been performed, it is possible to significantly reduce the wave of the signal amplitude by the amplifier gain adjustment, to ensure the quality of the subsequent synchronization code detection .

  These and other advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments of the present invention with reference to the drawings.

  The invention can be better understood with reference to the following description with reference to the drawings. In all the drawings, the same or similar components are denoted by the same or similar reference numerals. The above drawings, together with the following specific description, form a part of this disclosure, and are used to explain the preferred embodiments of the present invention and to interpret the principles and advantages of the present invention.

  An exemplary embodiment of the invention will now be described with reference to the drawings. In the interest of clarity and simplicity, not all features of an actual embodiment are described in the specification. However, it should be understood that in the process of developing such a practical example, more decisions must be made specific to the embodiment in order to achieve the specific goals of the developer. For example, those restrictions related to the system and business are satisfied, and these restrictions may vary from embodiment to embodiment. It should also be understood that although development work can be very complex and time consuming, such development work is routine work for those skilled in the art who benefit from the content of the present disclosure.

  Here, in order to avoid obscuring the present invention due to unnecessary details, the drawings show only the device structure and / or processing steps closely related to the technical solution according to the present invention, Other details that are largely unrelated to the present invention are omitted.

  FIG. 1 is a flowchart illustrating a method for detecting a synchronization code from a signal output from an AGC unit in a TDD system according to an embodiment of the present invention.

に対して同期符号検出を行って、上記正規化された信号

における同期符号の位置及びタイプを特定する。 As shown in FIG. 1, after the downsampled signal is received, the AGC gain change on the signal is compensated based on the difference between the current AGC gain of the AGC unit and the predetermined target gain in step S110. Te to obtain a stable sample signal amplitude. In step 120, for each sample point of the compensated sample signal r, using the statistics of all sample points in the corresponding normalization window centered on that sample point A normalized signal is obtained by normalizing the sample point. In step S130, the normalized signal

And the above normalized signal

Specifies the position and type of the synchronization code.

  Here, the downsampled signal mentioned in step S110 is actually a signal obtained by downsampling the signal output from the automatic gain control (AGC) unit. FIG. 2 is a structural diagram illustrating an AGC unit according to an embodiment of the present invention.

内の信号ｒ（ｔ）の平均電力Ｐ（ｔｉ）を求める方法と、以下の等式（２）により平均電力Ｐ（ｔｉ）の対数値と目標電力Ｐ_{ｔａｒｇｅｔ}との差ΔＧを求める方法と、以下の等式（３）により前回の利得値Ｇ（ｎ−１）から現在利得値Ｇ（ｎ）を取得する方法とを含む。

ただし、

は測定の開始時間であり、

は測定時間

内のサンプルポイントの数である。また、以下の等式（４）を利用して目標電力Ｐ_{ｔａｒｇｅｔ}を算出しても良い。

ただし、

であり、

はディジタル・アナログコンバータ（ＡＤＣ）のビット数である。

は、信号のピーク対平均電力比（ｐｅａｋ−ｔｏ−ａｖｅｒａｇｅ ｐｏｗｅｒ ｒａｔｉｏ）及びチャンネルの変化などの要素を考慮した余裕量であり、

のうちで値を取ることができる。 As shown in FIG. 2, the AGC unit includes, for example, a variable gain amplifier (VGA) 210, an analog-to-digital (AD) converter 220, an automatic gain generator 230, and a digital-to-analog (DA) converter 240. It is configured with. The received analog signal is amplified through the VGA 210, the amplified gain is determined by the output of the automatic gain generator 230, and the amplified signal enters the AD converter 220 into the digital signal r (t). Converted. The quantized digital signal r (t) is output as an output signal. On the other hand, the quantized digital signal r (t) is also input to the automatic gain generator 230, and the automatic gain generator 230 uses the gain value G (n) (current gain) to be used based on the strength of the signal r (t). Also called). The current gain G (n) is output to the compensation unit 710 shown in FIG. The calculation method of the current gain G (n) is, for example, the measurement time according to the following equation (1).

A method for obtaining an average power P (ti) of the signal r (t) in the signal, a method for obtaining a difference ΔG between the logarithmic value of the average power P (ti) and the target power P _target by the following equation (2): And a method of obtaining the current gain value G (n) from the previous gain value G (n−1) by the following equation (3).

However,

Is the start time of the measurement,

Is the measurement time

Is the number of sample points in. Alternatively, the target power P _target may be calculated using the following equation (4).

However,

And

Is the number of bits of the digital-to-analog converter (ADC).

Is a margin considering factors such as the peak-to-average power ratio of the signal and channel change,

The value can be taken out of.

The output signal r (t) (time domain signal) is subjected to low-pass filtering through, for example, a low-pass filter LPF, thereby removing frequency information other than the bandwidth occupied by the synchronization code. In addition to this low-pass filtering process, it is clear that unnecessary frequency information can be removed using other processing forms. Therefore, the low-pass filtering process is not shown in the drawing. Thereafter, the filtered signal is transmitted to an independent down-sampling unit and down-sampling is performed, so that a down-sample signal r _DS can be obtained. Since the synchronization code occupies only six RBs centered on the carrier frequency, it is necessary to downsample the baseband sampling rate in consideration of the realization complexity of the subsequent units. As an example, a filter with a baseband of 1.4 MHz is used corresponding to a baseband sampling rate of 30.72 MHz, and 16 times downsampling is used. Further, the downsampling unit can be integrated in the preprocessing unit 720 shown in FIG.

Thereafter, a change in the AGC gain on the downsample signal r _DS is compensated based on the difference between the current AGC gain G (n) of the AGC unit and the predetermined target gain G _target (n). Therefore, the loss of synchronization performance due to different AGC gains within the same code is compensated by adjusting the signal power to a certain range. FIG. 3 shows one specific example S310 of step S110 shown in FIG.

As shown in FIG. 3, first, in step S312, the updated gain values within a certain time of the AGC unit are averaged to generate a target gain G _target (n). For example, the target gain G _target (n) is calculated according to equation (5), and the latest N updated gain values received from the AGC unit are averaged.

  N can select the number of AGC updates within 5 ms, and may vary depending on the AGC measurement time, the AGC update period, and the like. Preferably, N ≧ 4. Further, the corresponding time zone may not be 5 ms. When the coherence time indicating the similarity of the radio channel is much larger than 5 ms, the time zone is lengthened, and when the coherence time is much smaller than 5 ms, the time zone is shortened.

Next, in step S314, the compensation factor f _b is specified based on the difference between the current AGC gain G (n) and the target gain G _target (n). When the gain of AGC is expressed by a linear value, the compensation factor f _b is a value G _target (n) / G (n) of the ratio between the target gain and the current AGC gain.

となる。 When the gain of AGC is expressed as a logarithmic value, the compensation factor f _b is

It becomes.

Thereafter, in step S316, by using the compensation factor _{f b} to compensate for the AGC gain of the down-sample signal _{r DS.} Specifically, over the down-sample signal r _DS compensation factor f _b, to obtain a stable sample signal r of amplitude.

  Here, AGC gain compensation is performed on the sample signal. However, due to the influence of the VGA device, a deviation often occurs between the actual VGA amplification gain and the set value of the automatic gain generator 230. Therefore, in order to eliminate the influence of the AGC misadjustment, it is necessary to further perform a preliminary process on the compensated sample signal r before performing the synchronization code detection.

  Returning to FIG. 1, in step S120, for each sample point of the compensated sample signal r, using the statistics of all sample points in the corresponding normalization window centered on that sample point. The sample point is normalized to obtain a normalized signal. FIG. 4 shows one specific example S420 of step S120 shown in FIG.

を取得する。ここで、Ｗ_ｎｏｒｍはノーマライズウインドウの長さであり、ノーマライズウインドウ内のサンプルポイントの数を示す。Ｗ_ｎｏｒｍ／２だけ遅延させることによって、中心ウインドウの演算を実現する。通常の探索範囲は、１フレームの時間である。Ｗ_ｎｏｒｍは、２のＮ乗を使用し、Ｎの範囲は、３−８であることが好ましい。 As shown in FIG. 4, in step S422, the compensated sample signal r is delayed by a time corresponding to W _norm / 2 sample points.

To get. Here, W _norm is the length of the normalize window and indicates the number of sample points in the normalize window. The center window is calculated by delaying it by W _norm / 2. The normal search range is one frame time. W _norm uses 2 to the power of N, and the range of N is preferably 3-8.

Further, in step S424, for each sample point of the compensated sample signal r, a normalization factor corresponding to the sample point using all the sample points in the corresponding normalization window centered on the sample point. Is calculated. When calculating the normalization factor, the statistical values of all sample points are used. For example, the statistical value is an average value by the amplitude of the signal.

に対して、以下の式（６）により、受信信号

を中心とするノーマライズウインドウ内におけるすべてのサンプルポイントの平均ノルムの値を採用して受信信号

に対応する正規化因子Ｎ（ｍ， ｋ）を算出する。ノーマライズウインドウの長さはＷ_ｎｏｒｍである。

或いは、以下の式（７）により正規化因子Ｎ（ｍ， ｋ）を算出してもよい。

ただし、α及びβは実験によって最適化され、最適な実施例は

となる。その他の好適な値として、

及び

がある。更に簡単にするために、

が採用されてもよく、即ち、等式（７）を簡単にすると以下になる。

補償されたサンプル信号ｒの各サンプルポイントに対して、好ましくは、等しいノーマライズウインドウの長さＷ_ｎｏｒｍを使用する。 For example, the received signal of the kth sample point from the receiving antenna m of the compensated sample signal r

For the received signal, the following equation (6)

Received signal using the average norm value of all sample points within the normalization window

A normalization factor N (m, k) corresponding to is calculated. The length of the normalize window is W _norm .

Or you may calculate the normalization factor N (m, k) by the following formula | equation (7).

However, α and β are optimized by experiment, and the optimal example is

It becomes. Other suitable values include

as well as

There is. To make it even easier,

May be employed, ie, simplifying equation (7):

For each sample point of the compensated sample signal r, preferably an equal normalization window length W _norm is used.

の相応するサンプルポイントを正規化して、正規化された信号

を取得する。図５は、図４に示されたステップＳ４２６の一つの具体例Ｓ５２６を示している。 Next, in step S426, the delayed signal is utilized using the normalization factor.

Normalized signal by normalizing corresponding sample points of

To get. FIG. 5 shows one specific example S526 of step S426 shown in FIG.

の最上位ビット検出を行い、正規化因子

の最上位ビットの位置ｎを探し、正規化因子

の代わりに２^ｎを使用し（即ちシングルビットが正規化因子

に近似し）、次にビットシフタ５２０で遅延信号

のｋ個目のサンプルポイントの受信信号

に対してｎビットシフト操作を行って、ｋ個目のサンプルポイントの正規化された信号

を取得する。遅延信号

の全てのサンプルポイントに対して各自の正規化因子を利用して正規化操作を順に行って、正規化された信号

を取得する。また、正規化因子

の近似精度を向上するために、マルチビット近似を使用することができる。即ち、Ａ＊２^ｎで正規化因子

を近似し、Ａが近似ビット数に関連するパラメータである。まず、１／Ａでｋ個目のサンプルポイントの受信信号

を乗算した後に、ｎビットシフトを行ってｋ個目のサンプルポイントの正規化された信号 As shown in FIG. 5, the normalization factor is detected by the most significant bit detector 510.

Detects the most significant bit of and normalizes

Find the most significant bit position n of, and normalization factor

Instead of 2 ⁿ (ie a single bit is a normalization factor)

Next, the bit shifter 520 delays the signal

The received signal at the kth sample point of

N-bit shifted operation on the kth sample point normalized signal

To get. Delay signal

Normalized signals by sequentially performing normalization operations using all normalization factors for all sample points of

To get. Also normalization factor

Multi-bit approximation can be used to improve the approximation accuracy of. That is, A * 2 ⁿ is a normalization factor

Where A is a parameter related to the approximate number of bits. First, the received signal of the kth sample point at 1 / A

And then the nth bit shifted and normalized signal of the kth sample point

を取得する。このような正規化を実現する方法の他のメリットは、正規化過程において０で割り算する問題が避けられることである。

To get. Another advantage of a method for realizing such normalization is that the problem of dividing by 0 in the normalization process is avoided.

に対して同期符号検出を行い、上記正規化された信号

における同期符号の位置及びタイプを特定する。 Returning to FIG. 1, next, in step S130, the normalized signal

, And the normalized signal

Specifies the position and type of the synchronization code.

がＰＳＳ検出ユニットに出力されてＰＳＳ検出が行われることにより、ＰＳＳの位置及びタイプが検出される。その後、正規化された信号

及びＰＳＳ検出ユニットによる検出結果がＳＳＳ検出ユニットに出力されてＳＳＳ検出が行われることにより、ＳＳＳの位置及びタイプが検出される。 For example, normalized signal

Is output to the PSS detection unit and PSS detection is performed, whereby the position and type of the PSS are detected. Then normalized signal

And the detection result by a PSS detection unit is output to an SSS detection unit, and SSS detection is performed, and the position and type of SSS are detected.

  FIG. 6 shows a comparison diagram of PSS correlation peaks obtained by PSS detection for signals that have been subjected to preliminary processing and signals that have not been subjected to preliminary processing with respect to the AGC gain change in the PSS code. Among them, the difference in AGC gain is 6 dB. As can be seen from FIG. 6, the PSS correlation peak of the signal that has not been preprocessed is not clear, and the value of the ratio between the correlation peak value and the correlation average value (peak-to-average value ratio) is low. After pre-processing the signal using the pre-processing unit according to the present invention, the acquired PSS correlation peak becomes very clear, the peak-to-average ratio increases, and the quality of PSS detection is significantly improved.

  In the above, the specific processing steps of steps S110 and S120 shown in FIG. 1 of the embodiment of the present invention have been described using FIG. 3 and FIG. 4, respectively, but the present invention is not limited to this.

As can be seen from the above, according to the technical solution of the present invention, it is possible to significantly reduce the influence on the process of detecting synchronization codes according to the wave of the originating signal amplitude in the gain adjustment of the amplifier. Specifically, for example, firstly, to reduce the wave of the signal amplitude by the AGC adjustment technique how the automatic gain control performs AGC gain compensation to take place the signal, then AGC adjust art methods normalization by further reducing the wave of the signal amplitude due to guarantee the quality of the subsequent synchronization code detection.

  In addition to the above-described method for detecting the synchronization code from the signal output from the automatic gain control AGC unit in the TDD system, according to the embodiment of the present invention, from the automatic gain control AGC unit in the TDD system corresponding to the above method. A device for detecting the synchronization code from the output signal is accordingly provided.

  FIG. 7 shows an apparatus 700 for detecting a synchronization code from signals output from an automatic gain control AGC unit in a TDD system according to an embodiment of the present invention.

を取得するように配置される予備処理ユニット７２０と、正規化された信号

に対して同期符号検出を行って、上記正規化された信号

における同期符号の位置及びタイプを特定するように配置される同期符号検出ユニット７３０と、を備える。 As shown in FIG. 7, an apparatus for detecting a synchronization code from signals output from an automatic gain control AGC unit in a TDD system according to an embodiment of the present invention includes a current AGC gain obtained from the AGC unit. and compensation unit 710 which is arranged to obtain a stable sample signal r width vibration by compensating the AGC gain changes on the down-sampled signal r _DS that after AD conversion based on the difference between the predetermined target gain For each sample point of the compensated sample signal r, the sample point is normalized using the statistics of all sample points within the corresponding normalization window centered on the sample point. Signal

A preprocessing unit 720 arranged to obtain a signal and a normalized signal

And the above normalized signal

A synchronization code detection unit 730 arranged to identify the position and type of the synchronization code in FIG.

  FIG. 8 shows a specific example 810 of the compensation unit 710 shown in FIG.

  As shown in FIG. 8, the compensation unit 810 includes a target gain generator 814 arranged to average a gain updated within a specific time by the AGC unit to generate a predetermined target gain, and a current AGC gain. And a compensation factor specifying unit 812 arranged to specify a compensation factor based on the difference between the predetermined target gain and the AGC gain change on the down-sampled signal using the compensation factor And a compensation execution unit 816 arranged as described above.

Specifically, the target gain generation unit 814 generates a target gain G _target (n) by averaging the gain values updated within a predetermined time from the AGC unit. For example, the compensation factor specifying unit 812 of the controller may calculate the compensation factor f _b based on the difference between the current AGC gain G (n) from the AGC unit and the target gain G _target (n) generated by the target gain generating unit 814. Is identified. When the gain of AGC is indicated by a linear value, the compensation factor f _b is a value G _target (n) / G (n) of the ratio between the target gain and the current AGC gain.

となる。 When the gain of AGC is expressed as a logarithmic value, the compensation factor f _b is

It becomes.

For example, the compensation execution portion 816 of the multiplier, the downsampled signal r _DS inputted, by multiplying the compensation factor f _b specified by the compensation factor specifying unit 812, obtains a stable sample signal r of amplitude .

  FIG. 9 shows one specific example 920 of the preliminary processing unit 720 shown in FIG.

を取得するように配置される遅延部９２２と、補償されたサンプル信号ｒのサンプルポイントそれぞれに対して、当該サンプルポイントを中心とする相応ノーマライズウインドウ内のすべてのサンプルポイントを利用して当該サンプルポイントに対応する正規化因子を算出するように配置される正規化因子算出部９２４と、正規化因子算出部９２４により算出された正規化因子を利用して遅延部９２２により出力された遅延信号

の相応するサンプルポイントを正規化して、正規化された信号

を取得するように配置される正規化実行部９２６とを備える。 As shown in FIG. 9, the preprocessing unit 920 _delays the compensated sample signal r by a time corresponding to W _norm (correspondingly the number of sample points in the normalization window) / 2 sample points.

For each sample point of the compensated sample signal r, the delay unit 922 is arranged to acquire the sample point by using all the sample points in the corresponding normalization window centered on the sample point. And a delay signal output by the delay unit 922 using the normalization factor calculated by the normalization factor calculation unit 924.

Normalized signal by normalizing corresponding sample points of

And a normalization execution unit 926 arranged to acquire

  The apparatus 700 shown in FIG. 7 and the units 710 to 720 included therein and the units 810 and 920 shown in FIGS. 8 and 9 perform various operations described with reference to FIGS. Can be arranged to perform. For further details of these operations, reference may be made to the examples, specific embodiments and examples described above and will not be described in detail here for the sake of brevity.

  The synchronous code detection apparatus according to each of the above embodiments of the present invention can be realized by a method of software, hardware, firmware, or any combination thereof, for example. When the synchronous code detection device is realized by adopting a hardware form, an integrated circuit chip, a network card, a USB bar (USB-bar), or the like can be adopted.

  Of course, the synchronous code detection device according to each of the above embodiments of the present invention may be realized as an independent functional configuration, or may be realized by being integrated with a corresponding terminal device. Therefore, a terminal device including such a synchronous code detection device should be included in the protection scope of the present invention. Such a terminal device may include, for example, a mobile phone, a portable computer, a laptop computer, a data card, a USB stick, an in-vehicle receiver, a smart appliance, a smart meter, and the like.

  As described above, detailed descriptions have been given using block diagrams, flowcharts, and / or examples, and different embodiments of apparatuses and / or methods according to examples of the present invention have been described. When one or more functions and / or operations are included in these block diagrams, flowcharts, and / or embodiments, those functions and / or operations in these block diagrams, flowcharts, and / or embodiments can be performed by those skilled in the art. Obviously, it can be implemented individually and / or jointly by various types of hardware, software, firmware or any actual combination thereof. In one class of embodiments, some portions of the subject matter described herein include an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a digital signal processor (DSP), or Other integrated forms are possible. On the other hand, some aspects of the embodiments described herein may, in whole or in part, be in the form of one or more computer programs (eg, one or more) that are executed on one or more computers. One or more computer programs executed on one computer system), one or more programs executed on one or more processors (eg, executed on one or more microprocessors) It can be envisaged by those skilled in the art that they can be equally implemented in an integrated circuit in the form of one or more programs), in the form of firmware, or in any practical combination thereof. And according to the content disclosed herein, it is within the abilities of those skilled in the art to design circuitry for this disclosure and / or to program software and / or firmware code for this disclosure. Can be completed within.

  For example, the apparatus 700 and each component module, unit, and subunit can be configured by software, firmware, hardware, or any combination thereof. When implemented by software or firmware, a program constituting the software can be installed from a storage medium or a network to a computer having a dedicated hardware structure (for example, the computer 1600 shown in FIG. 16). The computer can execute various functions when various programs are installed.

  FIG. 16 shows a schematic block diagram of a computer that can be used to implement the method and apparatus according to an embodiment of the present invention.

  In FIG. 16, a central processing unit (CPU) 1601 executes various processes based on a program stored in a read-only memory (ROM) 1602 or a program loaded from a memory unit 1608 to a random access memory (RAM) 1603. To do. The RAM 1603 also stores data necessary for the CPU 1601 to execute various processes as necessary. The CPU 501, ROM 1602, and RAM 1603 are connected to each other via a bus 1604. An input / output interface 1605 is also connected to the bus 1604.

  An input unit 1606 (including a keyboard, a mouse, and the like), an output unit 1607 (including a display such as a cathode ray tube (CRT), a liquid crystal display (LCD), and a speaker), and a memory unit 1608 (including a hard disk) The communication unit 1609 (including a network interface card such as a LAN card and a modem) is connected to the input / output interface 1605. A communication unit 1609 executes communication processing via a network, for example, the Internet. A drive 1610 is also connected to the input / output interface 1605 as necessary. A removable medium 1611 such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, or the like can be mounted on the drive 1610 as necessary. Thereby, the read computer program is installed in the memory unit 1608 as necessary.

  When the above-described series of processing is realized by software, a program constituting the software can be installed from a network, for example, the Internet, or a storage medium, for example, a removable medium 1611.

  Those skilled in the art will recognize that such storage media are not limited to the removable media 1611 shown in FIG. 16 in which the program is stored and distributed away from the device to provide the program to the user. Should be understood. Examples of the removable medium 1611 include a magnetic disk (including a floppy (registered trademark) disk), an optical disk (including a compact disk / read-only memory (CD-ROM) and a digital versatile disk (DVD)), and a magneto-optical disk. A disk (including a mini disk (MD) (registered trademark)) and a semiconductor memory are included. Alternatively, the storage medium may be a hard disk included in the ROM 1602 and the memory unit 1608, in which a program is stored, and a hard disk distributed to a user together with a device including them.

  Therefore, the present invention provides a program product in which machine-readable instruction codes are stored. When the instruction code is read and executed by a machine, various methods according to the embodiment of the present invention can be executed. On the other hand, the above-mentioned various storage media on which such a program product is mounted are also included in the disclosure of the present invention.

  The method and apparatus according to the present invention can be applied not only to a TDD-LTE system but also to an IMT-Advanced system inherited by a future LTE system, such as a TDD-LTE Advanced system.

  In the foregoing description of specific embodiments of the invention, the features described and / or illustrated for one type of embodiment may be used in one or more other embodiments in the same or similar form. Or can be combined with features in other embodiments, or replaced with features in other embodiments.

  It should be emphasized that the word “comprising / having”, when used in the text, means the presence of a feature, element, step, or component, but one or more other features, elements, It does not exclude the presence or addition of steps or components.

  Further, the method of the present invention is not limited to being executed according to the time order described in the specification, and may be executed sequentially according to other time orders, may be executed in parallel, or may be executed individually. May be. Therefore, the execution order of the methods described herein does not limit the technical scope of the present invention.

の式で前記所定予定目標利得を算出するように配置され、
ただし、Ｎ（Ｎ≧４）は前記更新された利得の数であり、ｉ＝ｎのときのＧ（ｎ）は現在ＡＧＣ利得を示し、
前記補償因子特定部は、前記所定目標利得と現在ＡＧＣ利得との比の値、または前記所定目標利得と現在ＡＧＣ利得との差の値により前記補償因子を特定するように配置され、
前記補償実行部は、前記ダウンサンプリングされた信号に、前記補償因子を乗算して振幅の安定したサンプル信号を取得するように配置されることを特徴とする付記２に記載の装置。

（付記４）
前記予備処理ユニットは、
補償されたサンプル信号を、Ｗ_ｎｏｒｍ（相応のノーマライズウインドウ内のサンプルポイントの数）／２個のサンプルポイントの時間だけ遅延させて遅延信号を取得するように配置される遅延部と、
補償されたサンプル信号のサンプルポイントのそれぞれに対して、当該サンプルポイントを中心とする相応のノーマライズウインドウ内のすべてのサンプルポイントを利用して当該サンプルポイントに対応する正規化因子を算出するように配置される正規化因子算出部と、
正規化因子を利用して遅延された信号の相応サンプルポイントに対して正規化を行うように配置される正規化実行部と、を備えることを特徴とする付記１−３のいずれかに記載の装置。

（付記５）
前記正規化因子算出部は、補償されたサンプル信号のサンプルポイントそれぞれに対して、当該サンプルポイントを中心とする相応のノーマライズウインドウ内のすべてのサンプルポイントのノルムの値の平均値を利用して当該サンプルポイントに対応する正規化因子を算出するように配置されることを特徴とする付記４に記載の装置。

（付記６）
前記正規化実行部は、正規化因子に対して最上位ビット検出を行って最上位ビットの位置ｎを特定し、Ａ×２^ｎで正規化因子に対してビット近似を行い、遅延された信号の相応サンプルポイントに１／Ａを乗算してからｎビットシフト操作を行うように配置され、
前記Ａは、１より大きいか、又は等しい定数であることを特徴とする付記４に記載の装置。

（付記７）
更に、ＡＧＣユニットから出力された信号に対してローパスフィルタリングを行って、同期符号以外の周波数情報を除去するように配置されるフィルタ装置を備えることを特徴とする付記１−３のいずれかに記載の装置。

（付記８）
前記ＴＤＤ通信システムは、ＴＤＤ−ＬＴＥシステムまたはＴＤＤ−ＬＴＥ Ａｄｖａｎｃｅｄシステムであることを特徴とする付記１−３のいずれかに記載の装置。

（付記９）
自動利得制御ＡＧＣユニットから得られた現在ＡＧＣ利得と所定目標利得との差異に基づいて、ＡＤ変化後のダウンサンプリングされた信号上のＡＧＣ利得変化を補償して振幅の安定したサンプル信号を取得し、
補償されたサンプル信号のサンプルポイントそれぞれに対して、当該サンプルポイントを中心とする相応のノーマライズウインドウ内のすべてのサンプルポイントの統計値を利用して当該サンプルポイントを正規化して正規化された信号を取得し、
正規化された信号に対して同期符号検出を行って前記正規化された信号における同期符号の位置及びタイプを特定することを含むことを特徴とする、ＴＤＤ通信システムにおいて自動利得制御ＡＧＣユニットから出力された信号から同期符号を検出する方法。

（付記１０）
ＡＧＣ利得変化を補償することは、
前記ＡＧＣユニットの所定時間帯内に更新された利得を平均して前記所定目標利得を生成し、
現在ＡＧＣ利得と前記所定目標利得との差異に基づいて補償因子を特定し、
前記補償因子を利用して前記ダウンサンプリングされた信号上のＡＧＣ利得変化に対して補償を行うこと、を含むことを特徴とする付記９に記載の方法。

（付記１１）

の式で前記所定目標利得を算出し、
ただし、Ｎ（Ｎ≧４）は前記更新された利得の数であり、ｉ＝ｎのときのＧ（ｎ）は現在ＡＧＣ利得を示し、前記所定目標利得と現在ＡＧＣ利得との比の値、または前記所定目標利得と現在ＡＧＣ利得との差の値により前記補償因子を特定し、前記ダウンサンプリングされた信号に、前記補償因子を乗算して振幅の安定したサンプル信号を取得することを特徴とする付記１０に記載の方法。

（付記１２）
正規化を行うことは、補償された信号を、Ｗ_ｎｏｒｍ（相応のノーマライズウインドウ内のサンプルポイントの数）／２個のサンプルポイントの時間だけ遅延させて遅延信号を取得し、補償されたサンプル信号のサンプルポイントそれぞれに対して、当該サンプルポイントを中心とする相応のノーマライズウインドウ内のすべてのサンプルポイントを利用して当該サンプルポイントに対応する正規化因子を算出し、正規化因子を利用して遅延された信号の相応サンプルポイントに対して正規化を行うことを含むことを特徴とする付記９−１１のいずれかに記載の方法。

（付記１３）
補償されたサンプル信号のサンプルポイントそれぞれに対して、当該サンプルポイントを中心とする相応のノーマライズウインドウ内のすべての複数のサンプルポイントの平均ノルムの値を利用して当該サンプルポイントに対応する正規化因子を算出することを特徴とする付記１２に記載の方法。

（付記１４）
相応のサンプルポイントを正規化することは、正規化因子に対して最上位ビット検出を行って最上位ビットの位置ｎを特定し、Ａ×２^ｎで正規化因子に対してビット近似を行い、遅延された信号の相応サンプルポイントに１／Ａを乗算してからｎビットシフト操作を行い、前記Ａは、１より大きいか、又は等しい定数であることを特徴とする付記１２に記載の方法。

（付記１５）
ＡＧＣ利得変化を補償する前に、ＡＧＣユニットから出力された信号に対してローパスフィルタリングを行って、同期符号以外の周波数情報を除去することをさらに含むことを特徴とする付記９−１１のいずれかに記載の方法。

（付記１６）
前記ＴＤＤ通信システムは、ＴＤＤ−ＬＴＥシステムまたはＴＤＤ−ＬＴＥ Ａｄｖａｎｃｅｄシステムであることを特徴とする付記９−１１のいずれかに記載の方法。

（付記１７）
前記ＴＤＤ通信システムにおける同期符号検出を実行する装置を備えることを特徴とする、付記１−８のいずれかに記載の端末装置。

（付記１８）
命令コードは、機械で読取られて実行される際に、付記９−１６のいずれかに記載のＴＤＤ通信システムにおいて同期符号検出を実行する方法を実行することができることを特徴とする、マシンで読み取り可能な命令コードが記憶されるプログラム・プロダクト。

（付記１９）
付記１８に記載のプログラム・プロダクトを搭載することを特徴とする記憶媒体。

以上のように本発明は具体的な実施例を説明することにより開示したが、当業者は添付された請求項の趣旨と範囲内に本発明に対する様々な修正、改良、又は同等物を企図することができる。これら、修正、改良、又は同等物は本発明の保護範囲内に含まれるものと認められるべきである。
The following additional notes will be further described with respect to the embodiments including the above examples.

(Appendix 1)
A device,
To obtain a stable sample signal width vibration by compensating the AGC gain variation on the down sampled signal after AD conversion based on the difference between the obtained current AGC gain and a predetermined target gain from the automatic gain control AGC unit A compensation unit arranged as follows:
For each sample point of the compensated sample signal, the normalized signal is normalized by using the statistics of all the sample points within the corresponding normalization window centered on that sample point. A pre-processing unit arranged to obtain,
A synchronization code detection unit arranged to perform synchronization code detection on the normalized signal to identify the position and type of the synchronization code in the normalized signal;
An apparatus for detecting a synchronization code from a signal output from an automatic gain control AGC unit in a TDD communication system.

(Appendix 2)
The compensation unit is
A target gain generator arranged to average the gains updated within a predetermined time period of the AGC unit to generate the predetermined target gain;
A compensation factor identifying unit arranged to identify a compensation factor based on a difference between a current AGC gain and the predetermined target gain;
A compensation executor arranged to compensate for an AGC gain change on the downsampled signal using the compensation factor;
The apparatus according to claim 1, further comprising:

(Appendix 3)
The target gain generator is

It is arranged to calculate the predetermined scheduled target gain by the following formula:
Where N (N ≧ 4) is the number of the updated gains, G (n) when i = n indicates the current AGC gain,
The compensation factor specifying unit is arranged to specify the compensation factor by a value of a ratio between the predetermined target gain and a current AGC gain or a value of a difference between the predetermined target gain and a current AGC gain,
The compensation execution portion A device according the down sampled signal, in appendix 2, characterized in that it is arranged to obtain a stable sample signal width vibration by multiplying the compensation factor.

(Appendix 4)
The preliminary processing unit is:
A delay unit arranged to obtain a delayed signal by delaying the compensated sample signal by a time of W _norm (the number of sample points in the corresponding normalization window) / 2 sample points;
For each sample point of the compensated sample signal, arrange to calculate the normalization factor corresponding to that sample point using all the sample points in the corresponding normalization window centered on that sample point A normalization factor calculation unit to be
A normalization execution unit arranged so as to normalize corresponding sample points of a signal delayed using a normalization factor, according to any one of appendix 1-3, apparatus.

(Appendix 5)
The normalization factor calculation unit uses, for each sample point of the compensated sample signal, an average value of norm values of all sample points within a corresponding normalization window centered on the sample point. The apparatus according to claim 4, wherein the apparatus is arranged to calculate a normalization factor corresponding to the sample point.

(Appendix 6)
The normalization execution unit performs the most significant bit detection on the normalization factor to identify the most significant bit position n, performs bit approximation on the normalization factor with A × 2 ⁿ , and delays the signal. The corresponding sample points are multiplied by 1 / A and then an n-bit shift operation is performed.
The apparatus of claim 4, wherein A is a constant greater than or equal to one.

(Appendix 7)
Furthermore, it includes a filter device arranged to perform low-pass filtering on the signal output from the AGC unit and remove frequency information other than the synchronization code, according to any one of appendix 1-3, Equipment.

(Appendix 8)
The apparatus according to any one of appendix 1-3, wherein the TDD communication system is a TDD-LTE system or a TDD-LTE Advanced system.

(Appendix 9)
Automatic gain control AGC unit currently obtained from, based on the difference between AGC gain and a predetermined target gain, acquired a stable sample signal width vibration by compensating the AGC gain changes on the down-sampled signal after AD change And
For each sample point of the compensated sample signal, the normalized signal is normalized by using the statistics of all the sample points within the corresponding normalization window centered on that sample point. Acquired,
Output from an automatic gain control AGC unit in a TDD communication system, comprising performing synchronization code detection on the normalized signal to identify the position and type of the synchronization code in the normalized signal Of detecting a synchronization code from a received signal.

(Appendix 10)
Compensating for AGC gain changes is
Averaging the gains updated within a predetermined time period of the AGC unit to generate the predetermined target gain;
Identifying a compensation factor based on a difference between the current AGC gain and the predetermined target gain;
The method of claim 9, comprising compensating for AGC gain changes on the downsampled signal using the compensation factor.

(Appendix 11)

The predetermined target gain is calculated by the following formula:
Where N (N ≧ 4) is the number of the updated gains, G (n) when i = n indicates the current AGC gain, and the value of the ratio between the predetermined target gain and the current AGC gain, or wherein identifying the compensation factor on the value of the difference between the predetermined target gain and the current AGC gain, the down-sampled signal to obtain a stable sample signal width vibration by multiplying the compensation factor The method according to Supplementary Note 10.

(Appendix 12)
Performing normalization delays the compensated signal by a time of W _norm (the number of sample points in the corresponding normalization window) / 2 sample points to obtain a delayed signal and compensated sample signal For each sample point, calculate the normalization factor corresponding to the sample point using all the sample points in the corresponding normalization window centered on the sample point, and delay using the normalization factor 120. A method according to any of clauses 9-11, comprising normalizing the corresponding sample points of the processed signal.

(Appendix 13)
For each sample point of the compensated sample signal, the normalization factor corresponding to that sample point using the value of the average norm of all the multiple sample points within the corresponding normalization window centered on that sample point 13. The method according to appendix 12, wherein the method is calculated.

(Appendix 14)
Normalizing the corresponding sample points involves detecting the most significant bit for the normalization factor to identify the most significant bit position n, performing bit approximation to the normalization factor with A × 2 ⁿ , 13. The method of claim 12, wherein the corresponding sample point of the delayed signal is multiplied by 1 / A and then an n-bit shift operation is performed, wherein A is a constant greater than or equal to one.

(Appendix 15)
Any one of appendixes 9-11, further comprising: performing low-pass filtering on the signal output from the AGC unit before compensating for the AGC gain change to remove frequency information other than the synchronization code. The method described in 1.

(Appendix 16)
The method according to any one of appendixes 9-11, wherein the TDD communication system is a TDD-LTE system or a TDD-LTE Advanced system.

(Appendix 17)
The terminal device according to any one of appendices 1-8, comprising a device that performs synchronization code detection in the TDD communication system.

(Appendix 18)
When the instruction code is read and executed by a machine, the instruction code is read by a machine, characterized in that the method for performing synchronous code detection in the TDD communication system according to any one of Supplementary notes 9-16 can be executed. A program product in which possible operation codes are stored.

(Appendix 19)
A storage medium on which the program product according to appendix 18 is mounted.

Although the invention has been disclosed by describing specific embodiments, those skilled in the art will envision various modifications, improvements, or equivalents to the invention within the spirit and scope of the appended claims. be able to. These modifications, improvements, or equivalents should be recognized as being included within the protection scope of the present invention.

Claims (10)

An apparatus for detecting a synchronization code from a signal output from an AGC (Automatic Gain Control) unit that performs automatic gain control,
A compensation unit connected to the output of the AGC unit, the AGC gain change on the downsampled signal after AD conversion based on the difference between the current AGC gain obtained from the AGC unit and a predetermined target gain a compensation unit arranged to so as to obtain a stable sample signal width vibration is compensated,
For each sample point of the compensated sample signal, the normalized signal is normalized by using the statistics of all the sample points within the corresponding normalization window centered on that sample point. A pre-processing unit arranged to obtain,
A synchronization code detection unit arranged to perform synchronization code detection on the normalized signal to identify the position and type of the synchronization code in the normalized signal;
A device comprising: The compensation unit is
A target gain generator arranged to average the gains updated within a predetermined time period of the AGC unit to generate the predetermined target gain;
A compensation factor identifying unit arranged to identify a compensation factor based on a difference between a current AGC gain and the predetermined target gain;
A compensation executor arranged to compensate for an AGC gain change on the downsampled signal using the compensation factor;
The apparatus of claim 1 comprising: The target gain generator is

Arranged to calculate the predetermined scheduled target gain in a formula,
Where N (N ≧ 4) is the number of the updated gains, G (n) when i = n indicates the current AGC gain,
The compensation factor specifying unit is arranged to specify the compensation factor by a value of a ratio between the predetermined target gain and a current AGC gain or a value of a difference between the predetermined target gain and a current AGC gain,
The compensation execution portion, the down sampled signal, The apparatus of claim 2 which is arranged to obtain a stable sample signal width vibration by multiplying the compensation factor. The preliminary processing unit is:
A delay unit arranged to obtain a delayed signal by delaying the compensated sample signal by a time of W _norm (the number of sample points in the corresponding normalization window) / 2 sample points;
For each sample point of the compensated sample signal, arrange to calculate the normalization factor corresponding to that sample point using all the sample points in the corresponding normalization window centered on that sample point A normalization factor calculation unit to be
The normalization execution part arrange | positioned so that it may normalize with respect to the corresponding sample point of the signal delayed using the normalization factor, The apparatus in any one of Claims 1-3.   The normalization factor calculation unit uses, for each sample point of the compensated sample signal, an average value of norm values of all sample points within a corresponding normalization window centered on the sample point. The apparatus of claim 4 arranged to calculate a normalization factor corresponding to a sample point. The normalization execution unit performs the most significant bit detection on the normalization factor to identify the most significant bit position n, performs bit approximation on the normalization factor with A × 2 ⁿ , and delays the signal. The corresponding sample points are multiplied by 1 / A and then an n-bit shift operation is performed.
The apparatus of claim 4, wherein A is a constant greater than or equal to one. And a low-pass filter device arranged to perform low-pass filtering on the signal output from the AGC unit and remove frequency information other than the synchronization code before the compensation of the AGC gain change. Item 4. The device according to any one of Items 1-3.   The apparatus in any one of Claims 1-3 applied to a TDD-LTE (Time Division Duplex-Long Term Evolution Advanced) system or a TDD-LTE Advanced (Time Division Duplex-Long Term Evolution Advanced) system. A method of detecting a synchronization code from a signal output from an AGC (Automatic Gain Control) unit that performs automatic gain control,
Based on the difference between the current AGC gain and a predetermined target gain obtained from the AGC unit, a stable sample signal width vibration by compensating the AGC gain changes on the down-sampled signal after AD changes, the AGC Obtained by the compensation unit connected to the output of the unit ,
For each sample point of the compensated sample signal, the normalized signal is normalized by using the statistics of all the sample points within the corresponding normalization window centered on that sample point. Acquired,
Performing synchronization code detection on the normalized signal to determine the position and type of the synchronization code in the normalized signal. Compensating for AGC gain changes is
Averaging the gains updated within a predetermined time period of the AGC unit to generate the predetermined target gain;
Identifying a compensation factor based on a difference between the current AGC gain and the predetermined target gain;
10. The method of claim 9, comprising compensating for AGC gain changes on the downsampled signal using the compensation factor.

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