A method and system for processing packet loss of a digital intercom

Abstract

This invention provides a method and system for handling packet errors in digital walkie-talkies, comprising: a transmitting end encoding and modulating a segment of voice signal to be transmitted into a data transmission unit, and repeating the encoding and modulation N times to form N data frames, which are then sent sequentially to a receiving end; the receiving end, upon receiving the N data frames, demodulates, decodes, and verifies each data frame; if any data frame verifies correctly, the voice information of that data frame is output; if all data frames verify incorrectly, the decoded voice information of all data frames is accumulated, a hard decision is performed, and the hard-determined voice information is output. This invention employs digital transmission encoding and decoding, making the voice signal more stable and reliable in air interface transmission; the repeated transmission method improves transmission reliability; and the accumulated hard decision cancels out the gain caused by noise, thereby ensuring the clarity and reliability of the voice signal.

Description

Technical Field

[0001] This invention relates to the field of wireless communication, and in particular to a method and system for handling packet errors in digital walkie-talkies. Background Technology

[0002] The main difference between digital and analog walkie-talkies lies in the use of digital technology for encoding, modulating, demodulating, and decoding voice information, as well as the use of digital signal processing algorithms for noise reduction and compression. Digital walkie-talkies transmit more stable signals and have better anti-interference capabilities than analog walkie-talkies, resulting in superior voice quality.

[0003] Digital walkie-talkies transmit the acquired voice signal through digital signal processing algorithms, performing noise reduction and compression, followed by encoding and modulation. At the receiving end, the signal is first demodulated and decoded, then processed again, and finally played back via a DAC. If the data packet verification is completely correct, the receiving end can fully recover all the information bits of the processed voice signal from the transmitting end. This is equivalent to the voice information passing through the air interface without any alteration, providing a lossless voice experience.

[0004] However, packets with decoding and verification errors are discarded because the location of the erroneous bits cannot be determined. In this case, although digital walkie-talkies remove some noise during transmission, the intermittent and stuttering voice information caused by packet loss degrades voice quality. Therefore, in the design of digital walkie-talkies, it is necessary to consider how to improve the success rate of data packet transmission and how to ensure the stability of voice quality when data packet transmission fails. Summary of the Invention

[0005] To address the problems existing in the prior art, a method and system for handling packet errors in digital walkie-talkies are provided. This method can solve the problem of lag in digital walkie-talkies, improve the gain of digital walkie-talkie transmission, enhance transmission efficiency and sound quality, and enable digital walkie-talkies to achieve a better voice experience.

[0006] The technical solution adopted in this invention is as follows: A method for handling packet errors in digital walkie-talkies, comprising:

[0007] The transmitting end encodes and modulates a segment of voice signal to be transmitted into a data transmission unit, and repeats the encoding and modulation N times to form N data frames, which are then sent to the receiving end in sequence.

[0008] After receiving N data frames, the receiving end demodulates, decodes, and verifies them one by one. If any data frame is verified correctly, the voice information of that data frame is output. If all data frames are verified incorrectly, the voice information after decoding of all data frames is accumulated, a hard decision is made, and the voice information after the hard decision is output.

[0009] Furthermore, the data transmission unit includes data bits for the voice signal and redundant bits for verification.

[0010] Furthermore, the number of times the transmitting end repeats the coding modulation depends on the relationship between the digital air interface rate and the compressed voice rate. Where the digital air interface rate is N times the compressed voice rate, the coding modulation is repeated N times.

[0011] Furthermore, the hard decision method is as follows: the voice information after decoding all data frames is accumulated to form a new voice signal data bit sequence, and each bit is weighted and summed to obtain a total value; if the total value is greater than a set threshold, a decision is made on the accumulated result, and the result obtained from the decision is directly output without verification.

[0012] Furthermore, the set threshold is adjusted according to the actual channel conditions and bit error rate.

[0013] This invention also proposes a digital walkie-talkie packet error processing system, including a transmitter and a receiver. The transmitter includes a voice signal processing module and a digital encoding and modulation module; the receiver includes a demodulation module, a decoding and verification module, and a hard decision module.

[0014] In this process, after the transmitting end completes the voice signal processing, the digital encoding and modulation module encodes and modulates the voice signal N times to form N data frames, which are then sent to the receiving end in sequence. The receiving end demodulates, decodes, and verifies the N data frames in sequence through the demodulation module and the decoding and verification module, and determines whether to output the voice signal directly or after the hard decision module makes a decision based on the verification results.

[0015] Furthermore, the speech signal processing module is an ADC.

[0016] Furthermore, the digital encoding and modulation module includes an encoding module and a modulation module. The encoding module performs N repetitions of encoding, which is then modulated by the modulation module before being output. The number of repetitions N is a multiple of the digital air interface rate and the compressed speech rate.

[0017] Furthermore, at the receiving end, the decoded N data frames are verified. If any data frame is verified correctly, the voice information of that data frame is output. If all data frames are verified incorrectly, the voice information of all data frames is accumulated, and then a hard decision is made to output the voice information after the hard decision.

[0018] Furthermore, the hard decision module works as follows: it acquires the accumulated voice information, forms a new voice signal data bit sequence, performs weighted summation on each bit to obtain the total value; if the total value is greater than a set threshold, it makes a decision on the accumulated result and outputs the result directly without verification.

[0019] Compared with existing technologies, the beneficial effects of adopting the above technical solution are as follows:

[0020] 1. This invention uses digital transmission encoding and decoding, which can bring certain gains compared to analog walkie-talkie methods, making the voice signal more stable and reliable in air interface transmission.

[0021] 2. This invention employs a repeated transmission method, which improves transmission reliability. Since the throughput of the digital air interface is higher than the rate of compressed voice, the transmission unit can be repeatedly transmitted multiple times. As long as the receiving end receives a correctly verified packet, it can accept the result as the corresponding voice information.

[0022] 3. When the signal-to-noise ratio (SNR) is relatively high (below sensitivity), even if the decoding result has a verification error, there is still information (bit error rate greater than 50%, i.e., valid information exists). This is because the bit error rate of the decoding result increases as the SNR decreases. However, in the special application of speech, even if the speech information is not transmitted completely without distortion, due to the low discrimination ability of the human ear, subsequent speech processing can use noise reduction. Therefore, a small amount of erroneous bit information has a smaller impact on the continuity of speech than a data unit being discarded due to verification failure; in fact, it can ensure the continuity of speech.

[0023] 4. Even if the decoding result is incorrect after multiple transmissions, the present invention can cancel the gain caused by noise through hard decision after accumulation, thereby ensuring the clarity and reliability of the voice signal. Attached Figure Description

[0024] Figure 1 This is a schematic diagram illustrating the handling of packet errors in digital walkie-talkies proposed in this invention.

[0025] Figure 2 This is a schematic diagram of encoding and modulation in one embodiment of the present invention.

[0026] Figures 3(a)-3(c) This is a schematic diagram of the hard decision process in one embodiment of the present invention. Detailed Implementation

[0027] The embodiments of this application are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar modules or modules having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. Rather, the embodiments of this application include all variations, modifications, and equivalents falling within the spirit and scope of the appended claims.

[0028] To improve the voice transmission quality of digital walkie-talkies, resolve the issue of lag, and enhance transmission gain, efficiency, and sound quality, thereby providing a better voice experience, this invention proposes a method for handling packet errors in digital walkie-talkies, specifically including:

[0029] The transmitting end encodes and modulates a segment of voice signal to be transmitted into a data transmission unit, and repeats the encoding and modulation N times to form N data frames, which are then sent to the receiving end in sequence.

[0030] After receiving N data frames, the receiving end demodulates, decodes, and verifies them one by one. If any data frame is verified correctly, the voice information of that data frame is output. If all data frames are verified incorrectly, the voice information after decoding of all data frames is accumulated, a hard decision is made, and the voice information after the hard decision is output.

[0031] Finally, the obtained speech signal data bit sequence is directly output to the next level of speech processing.

[0032] In this embodiment, the data transmission unit includes data bits of the voice signal and redundant bits for verification. Correspondingly, each data frame contains data bits of the voice signal and redundant bits for verification.

[0033] Since the throughput of the digital air interface is higher than the rate of the compressed voice, the transmission unit can transmit multiple times. That is, the number of times the transmitting end repeats the encoding and modulation depends on the relationship between the digital air interface rate and the compressed voice rate. In this embodiment, the digital air interface rate is N times the compressed voice rate, so the encoding and modulation are repeated N times.

[0034] It should be noted that data that fails verification is not discarded in this embodiment, but is used for subsequent hard decision-making. When the signal-to-noise ratio is relatively high (below sensitivity), even if the decoding result has a verification error, there is still information (bit error rate greater than 50%, i.e., valid information exists). This is because the bit error rate of the decoding result increases as the signal-to-noise ratio decreases. In the special application of speech, even if the speech information is not transmitted completely without distortion, due to the low resolution of the human ear, subsequent speech processing can use noise reduction. Therefore, a small amount of erroneous bits has a smaller impact on the continuity of speech than discarding a data unit due to verification failure; in fact, it can ensure the continuity of speech.

[0035] Therefore, if the verification fails after decoding all N data frames, the information from all N decoding attempts is summed to form a new audio signal data bit sequence. This sequence represents the audio information of the transmission unit, but it may contain a certain number of erroneous bits. To reduce the impact of these erroneous bits, the data bits can be summed during the decoding process. In this embodiment, the audio information after decoding all data frames is summed to form a new audio signal data bit sequence, and each bit is weighted and summed to obtain a total value. If the total value is greater than a set threshold, the summation result is judged, and the result is output directly without verification. Note that the bit error rate of the decoding result increases as the signal-to-noise ratio decreases.

[0036] In practical applications, the threshold can be adjusted according to the actual channel conditions and bit error rate.

[0037] To further illustrate the solution proposed in this invention, a simple voice signal transmitted using WIoTa as the digital transmission protocol is used as an example:

[0038] Assume the transmitting end generates a speech signal, performs sampling and encoding processing to obtain a data transmission unit. The transmitting end then encodes and modulates each of the three transmission units to obtain three digital signals. See [link to documentation] for details. Figure 2 The transmitter sends three digital signals to the receiver via the WIoTa digital air interface.

[0039] The receiver receives three data signals and demodulates and decodes them respectively to obtain the decoding result shown in Figure 3(a). The decoding result is checked. If any signal passes the check, it is directly output; if all fail the check, the receiver accumulates the three decoding results to obtain the accumulated result shown in Figure 3(b). The receiver performs a hard decision on the accumulated result. The hard decision depends on the information being added. If it is a binary field, the addition of multiple data bits is still 0 / 1. If it is not a binary field, it is added according to the addition of the GF(X) field to obtain the result that is considered to be in the original field. In this example, (0,1) is judged as 0 and (2,3) is judged as 1 (this example is a binary field of GF(2), so the addition of multiple 01s is still 01), resulting in the final voice information shown in Figure 3(c).

[0040] After noise reduction, the final speech signal can be correctly restored. This speech signal can then be processed for applications such as speech recognition and speech synthesis. This invention effectively improves the stability and continuity of the speech signal during WIoTa digital air interface transmission through digital transmission encoding and decoding, repeated transmission, and cumulative hard decision-making, enabling subsequent speech processing modules to process the signal more accurately.

[0041] Meanwhile, the present invention also proposes a digital walkie-talkie packet error processing system, including a transmitter and a receiver. The transmitter includes a voice signal processing module and a digital encoding and modulation module; the receiver includes a demodulation module, a decoding and verification module, and a hard decision module.

[0042] In this process, after the transmitting end completes the voice signal processing, the digital encoding and modulation module encodes and modulates the voice signal N times to form N data frames, which are then sent to the receiving end in sequence. The receiving end demodulates, decodes, and verifies the N data frames in sequence through the demodulation module and the decoding and verification module, and determines whether to output the voice signal directly or after the hard decision module makes a decision based on the verification results.

[0043] In this embodiment, the speech signal processing module is an ADC.

[0044] The digital encoding and modulation module includes an encoding module and a modulation module. The encoding module performs encoding N times, and then the output is modulated by the modulation module. The number of encoding repetitions N is a multiple of the digital air interface rate and the compressed speech rate.

[0045] When the signal-to-noise ratio is relatively high (before reaching the sensitivity threshold), even if the decoding result is incorrect, there is still information (if the bit error rate is greater than 50%, then there is valid information). Therefore, at the receiving end, the decoded N data frames are checked. If any data frame is checked correctly, the voice information of that data frame is output. If all data frames are checked incorrectly, the voice information of all data frames is accumulated, and then a hard decision is made to output the voice information after the hard decision.

[0046] Specifically, the hard decision module works as follows: it acquires the accumulated speech information, forms a new speech signal data bit sequence, performs weighted summation on each bit to obtain the total value; if the total value is greater than a set threshold, it makes a decision on the accumulated result and outputs the result directly without verification.

[0047] Example 1

[0048] This embodiment proposes a method for handling packet errors in digital walkie-talkies, including:

[0049] The transmitting end encodes and modulates a segment of voice signal to be transmitted into a data transmission unit, and repeats the encoding and modulation N times to form N data frames, which are then sent to the receiving end in sequence.

[0050] After receiving N data frames, the receiving end demodulates, decodes, and verifies them one by one. If any data frame is verified correctly, the voice information of that data frame is output. If all data frames are verified incorrectly, the voice information after decoding of all data frames is accumulated, a hard decision is made, and the voice information after the hard decision is output.

[0051] Example 2

[0052] Based on Example 1, the data transmission unit in this example includes data bits of the voice signal and redundant bits for verification.

[0053] Example 3

[0054] Based on Example 1, in this example, the number of times the transmitting end repeats the coding modulation depends on the relationship between the digital air interface rate and the compressed voice rate. Wherein, if the digital air interface rate is N times the compressed voice rate, then the coding modulation is repeated N times.

[0055] Example 4

[0056] Based on Example 1, the hard decision method described in this example is as follows: the voice information after decoding all data frames is accumulated to form a new voice signal data bit sequence, and each bit is weighted and summed to obtain a total value; if the total value is greater than a set threshold, the accumulated result is decided, and the result obtained by the decision is directly output without verification.

[0057] Example 5

[0058] Based on Example 4, the threshold set in this example is adjusted according to the actual channel conditions and bit error rate.

[0059] Example 6

[0060] This embodiment also proposes a digital walkie-talkie packet error processing system, including a transmitter and a receiver. The transmitter includes a voice signal processing module and a digital encoding and modulation module; the receiver includes a demodulation module, a decoding and verification module, and a hard decision module.

[0061] In this process, after the transmitting end completes the voice signal processing, the digital encoding and modulation module encodes and modulates the voice signal N times to form N data frames, which are then sent to the receiving end in sequence. The receiving end demodulates, decodes, and verifies the N data frames in sequence through the demodulation module and the decoding and verification module, and determines whether to output the voice signal directly or after the hard decision module makes a decision based on the verification results.

[0062] Example 7

[0063] Based on Example 6, the speech signal processing module in this example is an ADC.

[0064] Example 8

[0065] Based on Example 6, the digital encoding modulation module in this example includes an encoding module and a modulation module. The encoding module completes encoding N times, and then outputs the encoded data after modulation by the modulation module. The number of encoding repetitions N is a multiple of the digital air interface rate and the compressed speech rate.

[0066] Example 9

[0067] Based on Example 6, in this example, at the receiving end, the decoded N data frames are verified. If any data frame is verified correctly, the voice information of that data frame is output. If all data frames are verified incorrectly, the voice information of all data frames is accumulated, and then a hard decision is made to output the voice information after the hard decision.

[0068] Example 10

[0069] Based on Example 9, the hard decision module in this example works as follows: it acquires the accumulated voice information, forms a new voice signal data bit sequence, performs weighted summation on each bit to obtain the total value; if the total value is greater than a set threshold, it makes a decision on the accumulated result and outputs the result directly without verification.

[0070] The present invention can be well implemented through the above embodiments 1 to 10.

[0071] It should be noted that, in the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "set" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances. The accompanying drawings in the embodiments are used to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0072] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A method for handling packet errors in digital walkie-talkies, characterized in that, include: The transmitting end encodes and modulates a segment of voice signal to be transmitted into a data transmission unit, and repeats the encoding and modulation N times to form N data frames, which are then sent to the receiving end in sequence. After receiving N data frames, the receiving end demodulates, decodes, and verifies them one by one. If any data frame is verified correctly, the voice information of that data frame is output. If all data frames are verified incorrectly, the voice information after decoding of all data frames is accumulated, a hard decision is made, and the voice information after the hard decision is output. The hard decision method is as follows: the audio information after decoding all data frames is accumulated to form a new audio signal data bit sequence, and each bit is weighted and summed to obtain the total value; If the sum is greater than the set threshold, the accumulated result is judged and the result is output directly without verification. The hard decision depends on the information being added. If it is a binary field, the addition of multiple data bits will still result in 0 / 1. If it is not a binary field, the addition will be performed according to the addition method of the GF(X) field, and the result will still be the same as the result in the original field.

2. The method for handling error packets in digital walkie-talkies according to claim 1, characterized in that, The data transmission unit includes data bits for the voice signal and redundant bits for verification.

3. The method for handling packet errors in digital walkie-talkies according to claim 1 or 2, characterized in that, The number of times the transmitter repeats the coding modulation depends on the relationship between the digital air interface rate and the compressed voice rate. Where the digital air interface rate is N times the compressed voice rate, the coding modulation is repeated N times.

4. The method for handling error packets in digital walkie-talkies according to claim 1, characterized in that, The set threshold is adjusted according to the actual channel conditions and bit error rate.

5. A system for handling packet errors in digital walkie-talkies, characterized in that, It includes a transmitter and a receiver. The transmitter includes a voice signal processing module and a digital encoding and modulation module; the receiver includes a demodulation module, a decoding and verification module, and a hard decision module. In this process, after the transmitting end completes the voice signal processing, the digital encoding and modulation module encodes and modulates the voice signal N times to form N data frames, which are then sent to the receiving end in sequence. The receiving end demodulates, decodes, and verifies the N data frames in sequence through the demodulation module and the decoding and verification module, and determines whether to output the voice signal directly or after the hard decision module makes a decision based on the verification results. At the receiving end, the decoded N data frames are checked. If any data frame is checked correctly, the voice information of that data frame is output. If all data frames are checked incorrectly, the voice information of all data frames is accumulated, and then a hard decision is made to output the voice information after the hard decision. The hard decision module works as follows: it acquires the accumulated voice information, forms a new voice signal data bit sequence, and performs a weighted summation on each bit to obtain the total value. If the total value is greater than a set threshold, the accumulated result is decided, and the result of the decision is output directly without verification.

6. The digital walkie-talkie packet error processing system according to claim 5, characterized in that, The speech signal processing module is an ADC.

7. The digital walkie-talkie packet error processing system according to claim 5 or 6, characterized in that, The digital encoding and modulation module includes an encoding module and a modulation module. The encoding module performs N repetitions of encoding, which is then modulated by the modulation module before being output. The number of repetitions N is a multiple of the digital air interface rate and the compressed speech rate.

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