Signal processing system and method thereof
A signal processing system and method is disclosed, applicable to environment providing voltage to Class-H driver. When using the signal processing system, the first is to detect the volume change of inputted voice and use the detection result as a power source to generate an expectation value for the circuit; the input end of the power generation circuit also adds a voltage offset in addition to the expectation value, so that the output voltage from the output end of the power generator provided to the Class-H driver is higher than a fixed value. The signal processing system and method of the present invention can adjust automatically and rapidly the output voltage signal for the power voltage provided to the Class-H driver by using negative feedback controller (such as, negative feedback loop, voltage offset and proportional integral differential (PID)) based on the detected volume change of inputted voice.
1. A signal processing method, applicable to an environment of providing an output voltage to a Class-H driver, comprising the following steps:
performing sound detection: detecting volume changes in a left sound and a right sound of an input signal, and using detection results as an expected value; and
performing signal processing: receiving the expected value, a voltage offset, and a feedback voltage to perform voltage negative feedback processing to obtain an output voltage higher than a fixed value, and providing the output voltage to the Class-H driver so that the Class-H driver is able to adjust voltage supply according to the output voltage;
wherein the left sound and the right sound of the input signal inputted to the Class-H driver are delayed and when the left sound and the right sound of the input signal arrive at the Class-H driver, the output voltage is already inputted to the Class-H driver.
2. The signal processing method as claimed in claim 1 , wherein the performing sound detection step further comprises:
obtaining absolute values of input sounds: obtaining a left input signal absolute value from the left sound and obtaining a right input signal absolute value from the right sound;
obtaining maximum value: selecting a maximum sound from the left input signal absolute value and the right input signal absolute value;
performing level detection processing: performing level detection using different speeds for rising value and falling value; performing different rising and falling speed processing on the selected maximum sound; and transmitting a processed level signal;
performing low-pass filtering: filtering out high frequency variation from the level signal, and transmitting a processed low-pass signal; and
performing low level detection processing: performing low level detection on the low-pass signal, and generating an expected value for subsequent processing.
3. The signal processing method as claimed in claim 1 , wherein the step of performing signal processing further comprises:
performing offset processing: receiving the expected value, the voltage offset, and the feedback voltage, and performing negative feedback processing on the expected value, the voltage offset, and the feedback voltage;
performing response/stability processing: improving the response and stability of the negative feedback processing;
performing direct current to direct current (DC/DC) translation: generating a positive voltage and a negative voltage of the output voltage required by the Class-H driver; and
performing improving purity: receiving the positive voltage and negative voltage of the output voltage, purity of a power source, providing the feedback voltage for performing voltage negative feedback processing, and providing the positive voltage and negative voltage of the output voltage to the Class-H driver, so that the Class-H driver is able to adjust voltage supply according to the positive voltage and negative voltage of the output voltage.
4. The signal processing method as claimed in claim 3 , wherein the left sound and the right sound of the input signal inputted to the Class-H driver are delayed; and when the left sound and the right sound of the input signal arrive at the Class-H driver, the positive voltage and negative voltage of the output voltage are already inputted to the Class-H driver.
5. A signal processing system, applicable to an environment of providing an output voltage to a Class-H driver, comprising:
a volume unit (VU) meter module, for detecting volume changes in a left sound and a right sound, and using detection results as an expected value; and
a power source generation circuit, being a negative feedback circuit, having input ends for receiving the expected value outputted from the VU meter module, a voltage offset, and a feedback voltage outputted from an output end of the power source generation circuit to perform voltage negative feedback processing, the output end of the power source generation circuit outputting voltages higher than a fixed value to provide to the Class-H driver so that the Class-H driver is able to adjust voltage supply according to the positive voltage and negative voltage of the output voltage.
6. The signal processing system as claimed in claim 5 , operating with a first delay circuit and a second delay circuit; wherein, the first delay circuit and the second delay circuit respectively and simultaneously delay the left sound and right sound for a duration so that when the left sound and right sound arrive at the Class-H driver, the output voltage is already inputted to the Class-H driver.