[238603 7 5 96twf. doc/009 A7 B7 五、發明說明（/ ) 本發明是有關於一種補償訊號衰減之裝置與方法，且 特別是有關於一*種基於等化器之補償訊5虎哀減之裝置與方 法。 . 現今，傳遞訊號的方式大致可分爲有線通道（cable channel)傳輸與無線通道（air channel)傳輸。但不管是利用 何種通道傳輸，在傳遞連續訊號（例如類比訊號）的過程中， 都會受到鄰近符號的干擾（inter symbol interference，以下 簡稱ISI)，ISI即是連續訊號在傳遞的過程中，訊號彼此之 間會互相干擾（例如，可能使原本爲0的訊號變成爲1的訊 號），嚴重時甚至會干擾到前後數十個訊號，這種干擾對於 在做補償訊號之衰減時，影響特別大。 請參照第1圖，其繪示的是習知之補償訊號衰減之裝 置之方塊圖。類比訊號首先會透過有線通道或是無線通道 1〇2傳輸給自動增益控制器104，自動增益控制器104接收 到此類比訊號後，會放大此類比訊號再傳輸給類比數位轉 換器106,然後類比數位轉換器1〇6將此類比訊號轉換成 數位訊號後，最後輸出給等化器1〇8。在習知調整增益的 作法係利用累加器110與平均器112將多筆數位訊號做統 計、平均後，再傳送給自動增益控制對應電路U4，自動 增益控制對應電路1M會根據此平均過後的數値，調整自 動增益控制器104輸出給類比訊號之增益，使輸入等化器 之數位訊號能符合系統所需。 但習知在調整增益的作法上，累加器11〇需要統計大 量輸入訊號之振幅，因此會影響到整體裝置的運作時間， 3 _本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公髮— -----------^^f·-------訂--------- (請先閱讀背面之注意事項再填寫本頁) 經濟部智慧財產局員工消費合作社印製 [238603 7596twf.doc/009 A7 B7 五、發明說明（>) 且此數位訊號是原本就已經受到ISI的影響，大部分已經 失真，不是原本之數位訊號，所以利用此數位訊號來做統 計、平均，再輸出給自動增益控制對應電路114調整自動 增益控制器104輸出給類比訊號之增益，並不能獲得準確 的增益，以調整輸入的類比訊號。 因此知道習知在補償訊號衰減之裝置的作法上，有著 如下的缺點： 1. 需要儲存大量的數位訊號以統計輸入訊號之振幅’ 使整體裝置的運作時間延遲； 2. 訊號會受到ISI的影響，使增益預估不準；以及 3. 自動增益控制器之增益固定後，需預估等化器的起 使權重，但常常無法預估準確。 有鑑於此，本發明提供一種基於等化器之補償訊號衰 減之裝置，以改善習知的問題，包括：自動增益控制器’ 類比數位轉換器，自動增益控制對應電路與等化器。其中’ 自動增益控制器，用以放大類比信號後輸出。類比數位轉 換器，耦接至自動增益控制器之輸出端，用以將類比訊號 轉換爲數位訊號後輸出。自動增益控制對應電路，耦接至 自動增益控制器輸入端，用以調整自動增益器之增益。等 化器，耦接至類比數位轉換器之輸出端與自動增益控制對 應電路之輸入端，用以消除鄰近符號之干擾（ISI)。 在本發明的一個較佳實施例中，上述之自動增益控制 對應電路之輸入端訊號與輸出端訊號之關係爲任一單調遞 增函數。 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） -----------裝--------訂------1— (請先閱讀背面之注意事項再填寫本頁) 經濟部智慧財產局員工消費合作社印製 經濟部智慧財產局員工消費合作社印製 1238603 7596twf.doc/009 A7 ___ _B7 ___ 五、發明說明（)） 在本發明的另一個較佳實施例中，等化器可以用任何 可適應性的濾波器來達成，其構成模組可單純用前饋式等 化器，或再加上反饋式等化器以增加等化之效果。 本發明另提供一種基於等化器之補償訊號衰減之方 法，用以根據權重等化輸入訊號，其中此權重包括主權重， 此主權重爲等化器中最大的權重，此方法包括下列步驟： 首先根據主權重調整增益，再根據此增益調整輸入訊號， 然後根據此輸入訊號調整權重，再等化此輸入訊號，若權 重趨於穩定，則以此權重與此增益處理輸入訊號；若權重 不穩定，則跳回根據主權重調整增益步驟。 另外，本發明可用於有訓練信號之等化系統或肓目等 化系統(無訓練信號）。 本發明利用等化器消除ISI使輸入訊號前後干擾的問 題，因此可再利用自動增益控制對應電路調整自動增益控 制器對輸入訊號之增益，使系統漸漸趨於最佳增益値。 爲讓本發明之上述和其他目的、特徵和優點，能更加 明顯易懂，下文特舉較佳實施例，並配合所附圖示，做詳 細說明如下： 圖示簡單說明= 第1圖繪示的是習知之補償訊號衰減之裝置之方塊 圖； 第2圖繪示的是自動增益控制對應電路之輸入端訊號 與輸出端訊號之關係； 第3圖繪示的是本發明之補償訊號衰減之裝置之一較 5 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） -----------裝 *-------訂--------- (請先閱讀背面之注意事項再填寫本頁) [238603 7596twf.d〇c/〇09 A7 B7 五、發明說明（^V ) 佳實施例之方塊圖； 第4圖繪示的是基於等化器之補償訊號衰減之方法之 一'較佳實施例之流程圖；以及 第5圖繪示的是等化器內，前饋式等化器主權重與自 動增益控制器關係圖。 雷要元件標號： 102 :有線通道或無線通道 104 :自動增益控制器 106 :類比數位轉換器 108 :等化器 110 :累加器 112 :平均器 114 :自動增益控制對應電路 302 :有線通道或無線通道 304 :自動增益控制器 306 :類比數位轉換器 308 :前饋式等化器 310 :自動增益控制對應電路 312 :切割器 314 :反饋式等化器 316 :等化器 402〜412 :本發明方法之步驟流程圖 較佳實施例= 請參照第3圖，其繪示的是本發明之補償訊號衰減之 — — — — — — — — —^wi — — — — — — I— ^ ·1111111 (請先閱讀背面之注意事項再填寫本頁) 經濟部智慧財產局員工消費合作社印製 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） 1238603 7596twf. doc/009 A7 B7 五、發明說明（θ ) 裝置之一較佳實施例之方塊圖，並請同時參照第4圖，其 繪示的是本發明方法之步驟流程圖。本發明之基於等化器 之補償訊號衰減之裝置，包括：自動增益控制器304，類 比數位轉換器306,前饋式等化器308(位於等化器316內）， 自動增益控制對應電路310。其中自動增益控制器304，用 以放大類比信號後輸出。類比數位轉換器306，耦接至自 動增益控制器304之輸出端，用以將類比訊號轉換爲數位 訊號後輸出。自動增益控制對應電路310，耦接至自動增 益控制器304之輸入端，用以調整自動增益器304之增益。 等化器316，包括四部分：前饋式等化器308、反饋式等化 器314、切割器312與加法器318。前饋式等化器308，耦 接至類比數位轉換器306之輸出端與自動增益控制對應電 路310之輸入端，用以補償數位訊號之衰減。 舉例來說’當有訊號經過有線通道（cable channel)或 無線通道（air channel)時，會受到鄰近訊號的干擾（inter symbol interference，以下簡稱ISI)，因此訊號就會失真， 必須加以等化，但又因其振幅可能會變小，因此自動增益 控制對應電路310會根據預設的主權重（主權重爲數個權重 中權重値最大者)調整自動增益控制器304輸出給輸入訊號 的增益（步驟402)，接著再利用自動增益控制器304之增益 去放大此訊號的振幅（步驟404)，使輸出的訊號能達到類比 數位轉換器306能接受的範圍，然後類比數位轉換器306 接收到此訊號後會把此訊號轉換成數位訊號再傳送給前饋 式等化器3〇1 2，前饋式等化器308接受到此數位訊號後， (請先閱讀背面之注意事項再填寫本頁) 裝！ —訂i! 羲· 經濟部智慧財產局員工消費合作社印製 1 2 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公爱） 經濟部智慧財產局員工消費合作社印製 1238603 7596twf.d〇c/009 五、發明說明) 會調整數個權重（步驟4〇6)然後等化此數位訊號（步驟 408)，使其振幅能達到未受iSI與干擾的狀態，接著自動增 益控制對應電路31〇根據主權重調整自動增益控制器3〇4 輸出給輸入訊號的增益（步驟408)。 接著當下一個訊號經過有線通道或無線通道302時， 也會受到ISI的干擾，因此同樣地訊號就會失真，振幅可 能會變小或影響到前後的訊號，因此自動增益控制對應電 路310會根據調整後的主權重調整自動增益控制器3〇4輸 出給輸入訊號的增益（步驟4〇2)，再利用自動增益控制器304 之調整過後的增益去放大訊號的振幅（步驟4〇4)，使輸出的 訊號能達到類比數位轉換器306能接受的範圍。類比數位 轉換器306接收到此訊號後會把此訊號轉換成數位訊號再 傳送給前饋式等化器308，前饋式等化器3〇1接受到此數 位訊號後，會調整數個權重（步驟406)然後等化此數位訊號 (步驟4 〇 8)’使其振幅能達到未受I I與干擾的狀態。右寺 化器權重不穩定時，則跳回步驟402。若等化器權重趨於 穩定時，則固定住增益，以最後之增益、權重對往後輸入 訊號做補償（步驟412)。 S靑參照第5圖，其繪示的是等化器之補償訊號圖。等 化器可以用可適應性的濾波器來達成。等化器對輸入訊號 做補償的方法爲：依照各權重對相鄰信號的干擾做消除， 即前饋式等化器輸出：x2w2+x3w3+..· XmWm+...+XxWx，其中，乂1^爲欲等化的信號，而Xi，[238603 7 5 96twf. Doc / 009 A7 B7 V. Description of the invention (/) The present invention relates to a device and method for compensating signal attenuation, and in particular, to a kind of equalizer-based compensation signal. Subtraction device and method. At present, the methods of transmitting signals can be roughly divided into cable channel transmission and wireless channel (air channel) transmission. However, no matter which channel is used for transmission, in the process of transmitting continuous signals (such as analog signals), they will be subject to interference from adjacent symbols (hereinafter referred to as ISI). ISI is the signal of continuous signals in the process of transmission. They will interfere with each other (for example, the signal that is originally 0 may become a signal that is 1). In severe cases, it may even interfere with dozens of signals before and after. This interference has a particularly large impact on the attenuation of the compensation signal. . Please refer to Figure 1, which shows a block diagram of a conventional device for compensating for signal attenuation. The analog signal is first transmitted to the automatic gain controller 104 through a wired channel or a wireless channel 102. After receiving the analog signal, the automatic gain controller 104 amplifies the analog signal and then transmits it to the analog digital converter 106, and then the analog The digital converter 106 converts the analog signal into a digital signal, and finally outputs it to the equalizer 108. In the conventional method of adjusting the gain, the accumulator 110 and the averager 112 are used to calculate and average multiple digital signals, and then send them to the automatic gain control corresponding circuit U4. The automatic gain control corresponding circuit 1M will calculate the averaged data based on this Alas, adjust the gain output by the automatic gain controller 104 to the analog signal so that the digital signal of the input equalizer can meet the system requirements. However, in the practice of adjusting the gain, the accumulator 11 needs to count the amplitude of a large number of input signals, which will affect the operating time of the overall device. 3 _ This paper size applies the Chinese National Standard (CNS) A4 specification (210 X 297 Gongfa — ----------- ^^ f · ------- Order --------- (Please read the notes on the back before filling this page) Ministry of Economy Printed by the Intellectual Property Bureau's Consumer Cooperatives [238603 7596twf.doc / 009 A7 B7 V. Description of the invention (>) And this digital signal is already affected by ISI, most of it has been distorted, not the original digital signal, so Use this digital signal for statistics and averaging, and then output it to the automatic gain control corresponding circuit 114 to adjust the gain output by the automatic gain controller 104 to the analog signal. It is not possible to obtain accurate gain to adjust the input analog signal. The method of compensating for signal attenuation has the following disadvantages: 1. It needs to store a large number of digital signals to count the amplitude of the input signal, which delays the operation time of the overall device; 2. The signal will be affected by ISI, which will increase the The estimation is inaccurate; and 3. After the gain of the automatic gain controller is fixed, the starting weight of the equalizer needs to be estimated, but it is often impossible to estimate accurately. In view of this, the present invention provides a compensation signal based on the equalizer. Attenuation devices to improve the conventional problems, including: automatic gain controller 'analog digital converter, automatic gain control corresponding circuit and equalizer. Among them, the' auto gain controller 'is used to amplify the analog signal and output. Analog digital The converter is coupled to the output of the automatic gain controller for converting the analog signal into a digital signal and output. The corresponding circuit of the automatic gain control is coupled to the input of the automatic gain controller for adjusting the gain of the automatic gain controller. The equalizer is coupled to the output of the analog-to-digital converter and the input of the corresponding circuit of the automatic gain control to eliminate the interference of adjacent symbols (ISI). In a preferred embodiment of the present invention, the aforementioned automatic The relationship between the input signal and the output signal of the corresponding circuit of the gain control is any monotonically increasing function. This paper scale is applicable to China. Standard (CNS) A4 specification (210 X 297 mm) ----------- installation -------- order ------ 1-- (Please read the precautions on the back first (Fill in this page again.) Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs. Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs. 1236803 7596twf.doc / 009 A7 ___ _B7 ___ 5. Description of the invention ()) In the embodiment, the equalizer can be achieved by using any adaptive filter, and its constituent module can be simply a feedforward equalizer, or a feedback equalizer to increase the effect of equalization. The present invention further provides an equalizer-based method for compensating signal attenuation, which is used to equalize an input signal according to a weight, wherein the weight includes a main weight, and the main weight is the largest weight in the equalizer. The method includes the following steps: First adjust the gain according to the main weight, then adjust the input signal according to this gain, then adjust the weight according to this input signal, and then equalize this input signal. If the weight becomes stable, use this weight to process the input signal with this gain; if the weight is not If it is stable, go back to the step of adjusting the gain according to the main weight. In addition, the present invention can be applied to an equalization system with a training signal or an equalization system with no training signal (no training signal). In the present invention, the equalizer is used to eliminate the problem of interference between the input signal before and after the ISI. Therefore, the automatic gain control corresponding circuit can be used to adjust the gain of the input signal by the automatic gain controller, so that the system gradually approaches the optimal gain. In order to make the above and other objects, features, and advantages of the present invention more comprehensible, the following describes the preferred embodiments in detail with the accompanying drawings, and the detailed description is as follows: Brief description of the diagram = Figure 1 shows Figure 2 is a block diagram of a conventional device for compensating signal attenuation. Figure 2 shows the relationship between the input signal and output signal of the corresponding circuit of the automatic gain control. Figure 3 shows the compensation signal attenuation of the present invention. One of the devices is more than 5 paper sizes. It is applicable to China National Standard (CNS) A4 specification (210 X 297 mm). ----------- Installation * ------- Order ----- ---- (Please read the precautions on the back before filling in this page) [238603 7596twf.d〇c / 〇09 A7 B7 V. Description of the invention (^ V) Block diagram of the preferred embodiment; Figure 4 shows It is a flowchart of the preferred embodiment of the method of compensating the signal attenuation based on the equalizer; and FIG. 5 shows the relationship between the main weight of the feedforward equalizer and the automatic gain controller in the equalizer. . Thunder component numbers: 102: wired or wireless channel 104: automatic gain controller 106: analog-to-digital converter 108: equalizer 110: accumulator 112: averager 114: automatic gain control corresponding circuit 302: wired channel or wireless Channel 304: automatic gain controller 306: analog digital converter 308: feedforward equalizer 310: automatic gain control corresponding circuit 312: cutter 314: feedback equalizer 316: equalizer 402 to 412: the present invention The preferred embodiment of the method flow chart = Please refer to FIG. 3, which shows the compensation signal attenuation of the present invention — — — — — — — — — ^ wi — — — — — — — 1111111 (Please read the precautions on the back before filling out this page) The paper size printed by the Employees' Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs applies to Chinese National Standard (CNS) A4 (210 X 297 mm) 1238603 7596twf. Doc / 009 A7 B7 V. Description of the Invention (θ) A block diagram of a preferred embodiment of the device, please refer to FIG. 4 at the same time, which shows a flowchart of the steps of the method of the present invention. The equalizer-based device for compensating signal attenuation of the present invention includes: an automatic gain controller 304, an analog digital converter 306, a feedforward equalizer 308 (located in the equalizer 316), and an automatic gain control corresponding circuit 310 . The automatic gain controller 304 is used to amplify the analog signal and output it. The analog-to-digital converter 306 is coupled to the output terminal of the automatic gain controller 304 for converting the analog signal into a digital signal and outputting it. The automatic gain control corresponding circuit 310 is coupled to the input terminal of the automatic gain controller 304 to adjust the gain of the automatic gain controller 304. The equalizer 316 includes four parts: a feedforward equalizer 308, a feedback equalizer 314, a cutter 312, and an adder 318. The feedforward equalizer 308 is coupled to the output terminal of the analog-to-digital converter 306 and the input terminal of the automatic gain control corresponding circuit 310 to compensate for the attenuation of the digital signal. For example, when a signal passes through a cable channel or a wireless channel, it will be subject to interference from nearby signals (inter symbol interference (hereinafter referred to as ISI)), so the signal will be distorted and must be equalized. However, because its amplitude may become smaller, the automatic gain control corresponding circuit 310 will adjust the gain output by the automatic gain controller 304 to the input signal according to a preset main weight (the main weight is the largest of several weights) Step 402), and then use the gain of the automatic gain controller 304 to amplify the amplitude of the signal (Step 404), so that the output signal can reach the range acceptable by the analog-to-digital converter 306, and the analog-to-digital converter 306 receives this. After the signal, the signal will be converted into a digital signal and then sent to the feedforward equalizer 3102. After the feedforward equalizer 308 receives the digital signal, (Please read the precautions on the back before filling this page ) Install! —Order i! 羲 · Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 1 2 This paper size applies to the Chinese National Standard (CNS) A4 specification (210 X 297 public love) Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 1238603 7596twf. d〇c / 009 V. Description of the invention) It will adjust several weights (step 406) and then equalize this digital signal (step 408) so that its amplitude can reach the state without being affected by iSI and interference. The circuit 31 adjusts the gain output by the automatic gain controller 30 to the input signal according to the main weight (step 408). Then, when the next signal passes through the wired or wireless channel 302, it will also be interfered by ISI, so the signal will be distorted in the same way, the amplitude may become smaller or affect the front and back signals, so the automatic gain control corresponding circuit 310 will adjust according to the adjustment After the main weight is adjusted, the gain of the automatic gain controller 304 to the input signal is adjusted (step 402), and then the adjusted gain of the automatic gain controller 304 is used to amplify the amplitude of the signal (step 404), so that The output signal can reach a range acceptable by the analog-to-digital converter 306. After receiving the signal, the analog-to-digital converter 306 converts the signal into a digital signal and sends it to the feedforward equalizer 308. After the feedforward equalizer 301 receives the digital signal, it adjusts several weights. (Step 406) The digital signal is then equalized (Step 4 08) so that its amplitude can reach a state where it is not affected by II and interference. When the weight of the right templer is unstable, go back to step 402. If the equalizer weights become stable, the gain is fixed, and the final gain and weight are used to compensate the input signal in the future (step 412). That is, referring to FIG. 5, which shows the compensation signal diagram of the equalizer. Equalizers can be achieved with adaptive filters. The equalizer's method for compensating the input signal is to eliminate the interference of adjacent signals according to each weight, that is, the feedforward equalizer output: x2w2 + x3w3 + .. · XmWm + ... + XxWx, where 乂 1 ^ Is the signal to be equalized, and Xi,
爲前後的干擾信號。圖中D爲一單位延遲電路，wi ’ i=1〜X -----------裝--------訂---------^9. (請先閱讀背面之注意事項再填寫本頁) 1 本紙張尺度適用中國國家標準（CNS)A4規格（210 χ 297公釐） 7596twf.doc/009 A7 ____B7_____ 五、發明說明（°\ ) 爲權重，而Xi在這代表從數位類比轉換器輸入之數位訊號。 (請先閱讀背面之注意事項再填寫本頁) 其中，上述之前饋式等化器308可以用任何可適應性 的濾波器來達成，而自動增益控制對應電路310之輸入端 訊號與輸出端訊號之關係爲任一單調遞增函數。請參照第 2圖，其繪示的是自動增益控制對應電路之輸入端訊號與 輸出端訊號之關係圖。在圖中，若ufUj，則Af>A〆此爲單 調遞增函數的特性）。此時等化器的權重，包括主權重’則 依一般等化器係數調整方式調整，例如依最少平均平方法 (Least-Mean-Square，LMS)或是疊代最少平方法（Recursive· Least-Square，RLS) 〇 此外，基於等化器之補償訊號衰減之裝置更包括：切 割器312，耦接至等化器之輸出端，用以判斷訊號等化後 輸出準位；反饋式等化器，耦接至加法器318，使其輸出 與前饋式等化器之輸出相加，相加後之値輸入切割器312。 另外，本發明之裝置與方法適用於有訓練訊號之等化 系統與無訓練訊號之盲目等化系統。 經濟部智慧財產局員工消費合作社印製 綜上所述，本發明利用前饋式等化器308來消除輸入 訊號ISI的問題，但等化器也會部分彌補能量之衰減。當 輸入訊號能量不足時，主權重會變大以維持輸出能量的固 定，自動增益控制對應電路310會根據主權重調整自動增 益控制器304對輸入訊號之增益，因爲自動增益控制對應 電路310之輸入訊號與輸出訊號爲單調遞增函數，所以當 主權重變大，自動增益控制器304之增益也會隨之變大， 當增益變大時，主權重便不再變大，系統即趨於最佳增益 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） 1238603 7 5 96twf.doc/〇〇 9 五、發明說明（¾ ) 値，反之，當輸入訊號太大時，亦可利用此裝置與方法使 系統趨於最佳增益値。 $示上所述，本發明具有如下的優點· 1·不需要大量的數位訊號統計輸入訊號之振幅，因此 整體裝置的運作時間不會延遲； 2·利用等化器消除isi的影響，使增益預估準確’· 3·自動增益控制器之增益固定後，不需預估等化器的 起使權重；以及 4·不需累加器與平均器等額外電路，對輸入訊號做統 計，平均的工作，可有效節省成本與電路面積。 雖然本發明已以較佳實施例揭露於上，然其並非用以 限定本發明，任何熟習此技藝者，再不脫離本發明之精神 和範圍內，當可作各種之更動與潤飾，因此本發明之保護 範圍當視後附之申請專利範圍所界定者爲準。 丨丨丨！丨丨丨裝i丨—丨丨—丨訂丨丨丨！ (請先閱讀背面之注意事項再填寫本頁) 經濟部智慧財產局員工消費合作社印製 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公爱）Is the interference signal before and after. D in the figure is a unit delay circuit, wi 'i = 1 ~ X ----------- install -------- order --------- ^ 9. ( Please read the notes on the back before filling in this page) 1 This paper size applies the Chinese National Standard (CNS) A4 specification (210 χ 297 mm) 7596twf.doc / 009 A7 ____B7_____ 5. The description of the invention (° \) is the weight, Xi here represents the digital signal input from the digital analog converter. (Please read the precautions on the back before filling this page) Among them, the above feed-forward equalizer 308 can be achieved with any adaptable filter, and the input signal and output signal of the automatic gain control corresponding circuit 310 The relationship is any monotonically increasing function. Please refer to Figure 2, which shows the relationship between the input signal and the output signal of the corresponding circuit of the automatic gain control. In the figure, if ufUj, then Af> A (this is a characteristic of a monotonically increasing function). At this time, the weight of the equalizer, including the main weight, is adjusted according to the general equalizer coefficient adjustment method, such as the Least-Mean-Square (LMS) method or the Recursive Least- Square, RLS) 〇 In addition, the equalizer-based compensation signal attenuation device further includes: a cutter 312, coupled to the output terminal of the equalizer, used to determine the signal output level after equalization; feedback equalizer Is coupled to the adder 318, so that its output is added to the output of the feed-forward equalizer, and the added 値 is input to the cutter 312. In addition, the device and method of the present invention are applicable to equalization systems with training signals and blind equalization systems without training signals. Printed by the Consumer Cooperative of Intellectual Property Bureau of the Ministry of Economics In summary, the present invention uses a feed-forward equalizer 308 to eliminate the problem of input signal ISI, but the equalizer also partially compensates for the attenuation of energy. When the input signal energy is insufficient, the main weight will increase to maintain a fixed output energy. The automatic gain control corresponding circuit 310 will adjust the gain of the input signal by the automatic gain controller 304 according to the main weight because the automatic gain control corresponds to the input of the circuit 310 The signal and output signal are monotonically increasing functions, so when the main weight becomes larger, the gain of the automatic gain controller 304 will also increase. When the gain becomes larger, the main weight will no longer become large, and the system will become optimal. Gain This paper size applies the Chinese National Standard (CNS) A4 specification (210 X 297 mm) 1238603 7 5 96twf.doc / 〇〇9 V. Description of the invention (¾) 反 Conversely, when the input signal is too large, it can also be By using this device and method, the system tends to the optimal gain 値. As shown above, the present invention has the following advantages: 1. It does not need a large number of digital signals to count the amplitude of the input signal, so the operation time of the overall device will not be delayed; 2. The equalizer is used to eliminate the influence of ISI and make the gain Accurate estimation '· 3 · After the gain of the automatic gain controller is fixed, it is not necessary to estimate the starting weight of the equalizer; and 4 · No additional circuits such as the accumulator and averager are needed to make statistics on the input signal, and the average Work can effectively save costs and circuit area. Although the present invention has been disclosed above with a preferred embodiment, it is not intended to limit the present invention. Anyone skilled in the art can depart from the spirit and scope of the present invention and can make various modifications and retouches. Therefore, the present invention The scope of protection shall be determined by the scope of the attached patent application.丨 丨 丨!丨 丨 丨 Install i 丨 — 丨 丨 — 丨 Order 丨 丨 丨! (Please read the precautions on the back before filling out this page) Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs This paper applies the Chinese National Standard (CNS) A4 specification (210 X 297 public love)