Time-division method for playing multi-channel voice signals

• US 7,062,336 B1
• Filed: 10/08/1999
• Issued: 06/13/2006
• Est. Priority Date: 10/08/1999
• Status: Expired due to Term

• Current Assignee: Realtek Semiconductor Corp.
• Original Assignee: Realtek Semiconductor Corp.
• Inventors: Yang, Brian, Chen, Kuo-hsiang, Cheng, Fu-yuan
• Primary Examiner(s): Grier, Laura A.
• Application Number:
  US09/414,518
• Time in Patent Office: 2,440 Days
• Field of Search: 700/94, 370/369, 370/537, 370/538, 381/2, 381/80, 381/119, 455434- 37, 846/00, 704500-504, 704/258, 704/205, 704/201, 704/267
• US Class Current: 700/94
• CPC Class Codes: H03F 3/68 Combinations of amplifiers, e.g. multi-channel amplifiers for stereophonics power amplifiers using a combination of several semiconductor amplifiers H03F3/211; combinations of amplifiers using coupling networks with distributed constants H03F3/602

Abstract

A time-division method for playing multi-channel voice signals is provided to improve voice qualities of the multi-channel voice signals. The first feature of the present invention is that after time-division sampling, the voice signals can be directly sent to a subsequent voice generator without being demodulated beforehand. The second feature is that the ratio of a specific voice signal to a synthesized voice can be easily adjusted by changing the numbers of channels occupied by the specific voice. Consequently, the adjusting circuitry can be significantly simplified.

Claims

1. A method for time-divisionally outputting a plurality of voice signals, comprising the steps of:

generating the voice signals, wherein the voice signals are digital signals;

transmitting the voice signals through a plurality of channels, wherein each of the digital voice signals corresponds to one of the channels;

time-divisionally sampling the digital voice signals according to a periodic channel selecting signal to generate a multi-channel sampled signal;

sending the multi-channel sampled signal to a pulse width modulator to generate an output voice signal by adjusting the magnitude of the multi-channel sampled signal;

causing the pulse width modulator to generate based on the multi-channel sampled signal, pulses whose widths represent amplitudes of the output voice signal, converting the pulses corresponding to the multi-channel sampled signal to an analog output voice signal; and

amplifying the magnitude of the output voice signal; and

outputting the output voice signal.

2. The method as claimed in claim 1, wherein the period of the channel selecting signal corresponds to the number of the channels.

3. The method as claimed in claim 1, wherein the voice signals are eight-bit digital signals.

4. The method as claimed in claim 1, wherein each of the voice signals is sampled at least once per sampling cycle.

5. An apparatus for time-divisionally outputting a plurality of voice signals comprising:

a plurality of voice data generators for generating and transmitting the voice signals, wherein each of the voice signal generators includes at least a channel and each of the voice signals is transmitted through the corresponding channel;

a channel selector coupled to the voice data generators for time-divisionally sampling the voice signals according to a periodic channel selecting signal to generate a multi-channel sampled signal;

a voice generator including a pulse width modulator coupled to the channel selector for modulating the multi-channel sampled signal to generate an output voice signal, said pulse width modulator being arranged to generate, based on the multi-channel sampled signal, pulses whose widths represent amplitudes of the output voice signal, and said voice generator further converting said pulses into an output voice signal; and

a speaker coupled to the voice generator for outputting the output voice signal,

wherein the output voice signal is generated by adjusting magnitudes of the multi-channel sampled signals and converting the multi-channel sampled signal to the output voice signal, wherein the output voice signal is an analog signal.

6. The apparatus as claimed in claim 5, wherein the period of the channel selecting signal corresponds to the number of the channels.

7. The apparatus as claimed in claim 5, wherein the voice signals are eight-bit digital signals.

8. The apparatus as claimed in claim 5, wherein the most significant bit (MSB) of the multi-channel sampled signal is transmitted to the voice generator through a first pathway, and the remaining bits of the multi-channel sampled signal are transmitted to the voice generator through a second pathway.

9. The apparatus as claimed in claim 8, wherein the voice generator further includes a high-speed counter and a switch.

10. The apparatus as claimed in claim 9, wherein the switch is controlled according to the most significant bit of the multi-channel sampled signal.

11. The apparatus as claimed in claim 5, wherein the voice generator is a digital-to-analog converter.

12. The apparatus as claimed in claim 5, wherein the voice generator further includes a power amplifier for amplifying the magnitude of the output voice signal.

13. The apparatus as claimed in claim 5, wherein each of the voice signals is sampled at least once per sampling cycle.

14. An apparatus for time-divisionally outputting a plurality of voice signals comprising:

a plurality of voice data generators for generating and transmitting the voice signals, wherein each of the voice signal generators includes at least a channel and each of the voice signals is transmitted through the corresponding channel;

a time-division multiplexing unit coupled to the voice data generators for time-divisionally sampling the voice signals to generate a multi-channel sampled signal;

a voice generator coupled to the time-division multiplexing unit for modulating the multi-channel sampled signal to generate an output voice signal; and

a speaker coupled to the voice generator for outputting the output voice signal;

wherein the output voice signal generated by the voice generator contains voice information of the plurality of voice signals.

15. The apparatus as claimed in claim 14, wherein the ratio of a first voice signal in the multi-channel sampled signal is adjusted by controlling the number of channels occupied by the first voice signal.