Error concealment method and apparatus for mobile radio

Abstract

An error concealment method and apparatus for a mobile radio are described herein. A current position value is provided by a spatial position receiver. If available, a signal quality parameter associated with the current location value is retrieved from a database. If the signal quality parameter is available, a first error concealment method for the received audio signal is selected and applied depending on the signal quality parameter value. If the signal quality parameter associated with the current location value is unavailable and the received audio signal is corrupted, a more conservative second (default) error concealment method is applied to the received audio signal.

Description

Technical Field

[0001] The present disclosure relates to an error concealment method and apparatus for mobile radio. Background Art

[0002] In a typical digital radio system used in a vehicle, referred to herein as a mobile radio, it may not be possible to decode the audio frame and obtain the desired digital audio signal when reception conditions deteriorate. The data signal may be corrupted in transmission, typically resulting in a silent frame containing zeros at the source decoder output. In these cases, error concealment methods need to be applied to the audio signal.

[0003] Fast silence (where the audio is interrupted on the order of 30ms in the time span of one audio frame) is one error concealment strategy. This requires an advance buffering of one audio frame. Fast silence may be considered too abrupt, and so alternative methods of concealing corrupted audio frames may use frame repetition, noise substitution, and prediction.

[0004] In other scenarios, a simulcast, i.e., a secondary broadcast of the same radio program from a different source (e.g., analog broadcast on FM or digital broadcast on Internet radio) may be presented next to the primary broadcast. If the audio data of the primary broadcast is corrupted, the system can "mix in" the audio signal of the secondary broadcast. Summary of the invention

[0005] Various aspects of the disclosure are defined in the accompanying claims. In a first aspect, a method of error concealment for an audio signal of a mobile radio is provided, the method comprising: receiving a current position value provided by a spatial position receiver; determining whether at least one signal quality parameter associated with the current position value is available in a database; in response to the at least one signal quality parameter being available: selecting a first error concealment method for the received audio signal depending on the at least one signal quality parameter; applying the first error concealment method to the received audio signal; and in response to the at least one signal quality parameter associated with the current position value being unavailable and determining that the received audio signal is corrupted: applying a second error concealment method to the received audio signal.

[0006] In some embodiments, the at least one signal quality parameter comprises an audio impairment duration. In some embodiments, in response to the audio impairment duration being below a first time threshold, the first error concealment method comprises frame repetition. In some embodiments, in response to the audio impairment duration being below a first time threshold, the first error concealment method comprises switching to a secondary broadcast signal aligned with the received audio signal in at least one of time, spectrum, and level.

[0007] In some embodiments, in response to the audio corruption duration being above a second time threshold, the first error concealment method comprises at least one of an audio fade-in and an audio fade-out. In some embodiments, in response to the audio corruption duration being above a second time threshold, the first error concealment method comprises switching to a secondary broadcast signal and fading out at least one of spectral and level alignment with the received audio signal. In some embodiments, the at least one signal quality parameter comprises an audio corruption rate. In some embodiments, the method further comprises updating a database, the database comprising a plurality of database entries, each database entry comprising a position value and a signal quality parameter.

[0008] In some embodiments, the method further comprises, in response to the at least one signal quality parameter being unavailable: determining the at least one signal quality parameter of the received audio signal; and updating the database with a database entry comprising the at least one signal quality parameter and the current position value. In some embodiments, each database entry further comprises at least one of a timestamp value and a position visit count value, and the method further comprises updating the database with at least one of a timestamp value and a position visit count value of the current position.

[0009] In some embodiments, updating the database comprises: in response to the number of entries exceeding a maximum entry value, removing a selected one of the plurality of database entries based on at least one of the timestamp value and the location visit count value of each database entry. In some embodiments, determining the at least one signal quality parameter comprises determining that the received audio signal is corrupted. In some embodiments, the at least one signal quality parameter comprises a proportion of a number of corrupted audio frames during one of a predetermined duration and a predetermined distance.

[0010] In a second aspect, a controller for a mobile radio is provided, the controller comprising: a navigation input, the navigation input being configured to couple to a spatial position receiver; a radio reception condition input, the radio reception condition input being configured to receive a radio reception condition signal; an audio input, the audio input being configured to couple to an output of the radio receiver; and an audio output; wherein the controller is configured to: receive a current position value provided by the spatial position receiver; determine whether at least one signal quality parameter associated with the current position value is available in a database; in response to the at least one signal quality parameter being available: select a first error concealment method for a received audio signal depending on the at least one signal quality parameter; apply the first error concealment method to the received audio signal; and in response to the at least one signal quality parameter being unavailable, the controller is further configured to: predict whether the received audio signal will be damaged based on the radio reception condition signal; and in response to determining that the received audio signal will be damaged, apply a second error concealment method to the received audio signal.

[0011] In some embodiments, the controller further includes: a control module coupled to a database, the control module having a first control module input coupled to the navigation input, a second module input coupled to the radio reception condition input, and a control module output; an error concealment module, the error concealment module having a first error concealment input coupled to the audio input, a second error concealment input coupled to the control module output, and an error concealment output coupled to the audio output; wherein the control module is configured to: receive the current position value; determine whether at least one signal quality parameter associated with the current position value is available in the database; in response to the at least one signal quality parameter being available: select a first error concealment method for the received audio signal depending on the at least one signal quality parameter; control the error concealment module to apply the first error concealment method to the received audio signal; in response to the at least one signal quality parameter being unavailable: determine whether the received audio signal will be damaged based on the radio reception condition signal; control the error concealment module to apply the second error concealment method to the received audio signal.

[0012] In some embodiments, the at least one signal quality parameter comprises an audio impairment duration, and wherein in response to the audio impairment duration being below a first time threshold, the first error concealment method comprises frame repetition.

[0013] In some embodiments, the at least one signal quality parameter includes an audio impairment duration, and wherein in response to the audio impairment duration being below a first time threshold, the first error concealment method includes switching to a secondary broadcast signal that is aligned with the received audio signal in at least one of time, spectrum, and level.

[0014] In some embodiments, the at least one signal quality parameter comprises an audio corruption duration, and wherein in response to the audio corruption duration being above a second time threshold, the first error concealment method comprises at least one of an audio fade-in and an audio fade-out.

[0015] An embodiment of the controller may be included in a mobile radio receiver, the mobile receiver further comprising: a series arrangement of a tuner, a demodulator, a channel decoder and a source decoder; wherein the tuner is configured to receive a signal from an antenna, and the source decoder is configured to output a digital audio signal to the controller. The mobile radio receiver may further include a navigation module coupled to a navigation input of the controller. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In the drawings and description, like reference numerals refer to like features. Embodiments will now be described in detail only by way of example as illustrated by the accompanying drawings, in which:

[0017] Figure 1 A mobile radio according to an embodiment is shown.

[0018] Figure 2 Show Figure 1 Additional details of the mobile radio section.

[0019] Figure 3 A graph indicating an example variation over time of a bit error rate of a fast information channel of digital audio broadcasting (DAB+) during driving of a vehicle is shown.

[0020] Figure 4 Show Figure 3 Expanded details of the curve graph.

[0021] Figure 5 A method for error concealment for mobile radio according to an exemplary embodiment is shown.

[0022] Figure 6 A method for error concealment for mobile radio according to an exemplary embodiment is shown.

[0023] Figure 7 A method for error concealment for mobile radio according to an exemplary embodiment is shown.

[0024] Figure 8 Show updates by Figure 5 , Figure 6 or Figure 7 The error hiding method uses the database method.

[0025] It should be noted that the figures are diagrammatic and not drawn to scale. For clarity and convenience in the drawings, the relative sizes and proportions of the various parts of these figures have been shown as enlarged or reduced in size. The same reference numerals are generally used to refer to corresponding or similar features in modified and different embodiments. DETAILED DESCRIPTION

[0026] Figure 1 A mobile radio 100 according to an embodiment is shown. The mobile radio 100 may be, for example, a car radio or part of a car entertainment system. A first receiver, which may be a receiver for a DAB digital radio broadcast, includes a tuner 102, an orthogonal frequency division multiplexing (OFDM) demodulator 104, a channel decoder 106, and a source decoder 108. An antenna 112 is connected to the tuner 102. A tuner output 114 is connected to an input of the OFDM demodulator 104. An OFDM demodulator output 116 is connected to an input of the channel decoder 106. A channel decoder output 118 is connected to an input of the source decoder 108. An output of the source decoder 108, which may include signals from a plurality of broadcasts, is connected to an audio input 122 (s1) of a controller 120. Optionally, the mobile radio 100 may have a second receiver, for example, an Internet Protocol (IP) radio 124 having a signal output connected to the audio input 122 (s1). The controller 120 may have one or more radio reception condition inputs 130-1 (Qa), 130-2 (Qb), 130-3 (Qc) connected to the respective outputs of the OFDM demodulator 104, the channel decoder 106, and the source decoder 108. The controller 120 may have an audio output 128 (s2) and a navigation input 126 (p) connected to a navigation module 110, which may be, for example, a global positioning system (GPS) receiver or other spatial position receiver having means for determining position. Other radios may also include FM / AM analog receivers or other digital radio receivers that may provide multiple sources of the same audio content.

[0027] The antenna signal from the antenna 112 is converted into a digital data signal using the tuner 102 and the OFDM demodulator 104. The digital data signal is decoded into a digital received audio signal by the channel decoder 106 and decoded by the source decoder 108. When the data at the input of the source decoder 108 is valid, the source decoder 108 generates a received digital audio frame. Similarly, the IP radio receiver 124 can output a digital audio frame.

[0028] Figure 2Details of a controller 120 for a mobile radio 100 are shown. The controller 120 includes a control module 140, a memory including a location database 134, and an error concealment module 138. The control module 140 has inputs connected to the navigation input 126 and the radio reception condition input 130 and a control module output 142 connected to the error concealment module 138. The control module 140 is connected 136 to the location database 134. The error concealment module 138 has an input connected to the audio input 122 and an output connected to the audio output 128. The controller 120 may receive an input audio stream s1, location information p, and a radio reception condition signal Q that may be used to predict whether the audio signal will be corrupted. a , Q b , Q c The controller 120 may receive a condition signal Q from the radio a , Q b , Q c One or more signal quality parameters are derived. The signal quality parameters may be, for example, one or more of: a bit error rate, a duration for which the audio signal is considered corrupted, or a distance from a current location at which the audio signal is considered corrupted. The duration for which the audio signal is considered corrupted may be determined, for example, by evaluating whether the bit error rate is greater than a threshold for a predetermined duration. The distance from the current location at which the audio signal is considered corrupted may be determined, for example, by evaluating whether the bit error rate is greater than a threshold for a predetermined distance from the current location. The controller 120 may be implemented in hardware or a combination of hardware and software.

[0029] In operation, digital audio signal s1 is input to error concealment module 138. Operation of error concealment module 138 is controlled by control module 140 using control signal ("C"). Control module 140 additionally receives input p indicating the current position of the vehicle from navigation module 110 and exchanges data with database 134.

[0030] The error concealment module 138 can operate in several modes depending on when the audio is expected to be corrupted. In systems where only a single broadcast is available, there may be a short-term concealment strategy using frame repetitions and a long-term concealment strategy using audio fade-ins and fade-outs, for example. Other modes and concealment strategies are possible. Under normal reception conditions where error concealment is not required, the digital audio signal can be passed to the audio output 128 without modification, i.e., the signals s1 and s2 are identical.

[0031] In a system where simulcast is available, there may be, for example, three error concealment modes. For example, in the case of very short audio silence, the short-time mode may switch to an aligned secondary broadcast for a relatively short duration, and then return to the original source. Before switching back to the main broadcast, the medium-time mode may switch to an aligned secondary broadcast for a relatively long duration. This may be applicable, for example, to locations where there is intermittent audio. The long-time mode may switch to an aligned secondary broadcast for an indeterminate duration. The error concealment module 138 may gradually remove alignment, which may be one or more of level alignment, spectrum alignment, and time alignment with the original broadcast source. For example, when the first reception quality is very poor (because the vehicle is outside the range of the main broadcast), the alignment may need to be removed. In addition, removing the alignment in the long-time mode may be preferred because the alignment process is typically estimated based on short-term differences between broadcasts, and may be invalid over a longer period of time because it may depend largely on the frequency content when the signal is estimated.

[0032] Database 134 may store information about the spatial locations where audio corruption has occurred for a particular broadcast, and what type of corruption may be expected (e.g., short-term or longer-term). Database 134 may contain locations where audio corruption is expected in a given broadcast and corruption rates indicating the nature of the audio corruption. The spatial locations may be selected to be at least a certain distance apart, such as 20 meters, to limit the number of entries in the database.

[0033] The control module 140 may determine a preferred concealment strategy and update the database. When the signal quality metric Q indicates possible audio corruption, or if the audio data is corrupted, the control module 140 queries the database 134 with the current broadcast and current spatial position Pc received by the control module 140 periodically or only upon request from the navigation module 110. The response to the query is, for example, a corruption rate C(P) about the length or ratio of the audio data corruption, based on which a preferred error concealment strategy is determined, which is sent to the error concealment module 138 via the control signal C. The corruption rate C(P) is an example of a signal quality parameter. Instead of or in addition to the preferred concealment mode, the control signal C may also control the audio or mixing gain. In order to update the database 134, the control module 140 may evaluate the audio corruption during a certain time period to determine the length or ratio of the audio corruption. This information may be used to update the database 134 by adding new entries or adapting existing entries.

[0034] The corruption rate C(P) may be continuously monitored by the control module 140 and may indicate the type of audio signal corruption. In one example, the corruption rate C(P) is the length of the audio corruption. In this example, the control module 140 measures the time or distance of the audio signal corruption. In another example, the corruption rate is the proportion of a specific time or distance of audio signal corruption. In one example, a running buffer may be maintained as a memory of audio corruption, such as encoded as 0 / 1, which is updated for each audio frame. If the length of the running buffer is equal to 1 second (in frames), the average value of the elements corresponds to the proportion of corrupted audio frames in the past second.

[0035] In operation, the radio 100 may receive a radio reception condition signal Q predicting audio signal corruption, and a binary flag corresponding to a current or future broadcast if a look-ahead audio frame (lossless or corrupted) exists from one or more of the OFDM demodulator 104, the channel decoder 106, and the source decoder 108. When the radio reception condition signal Q indicates that the upcoming audio signal is corrupted, that is, if one or more of the metrics are above or below a certain threshold, the control module 140 queries the database 134 with the current broadcast and the current spatial position Pc obtained from the navigation module 110. If the current spatial position is not close enough to the position stored in the database 134, a default conservative error concealment strategy is initiated, such as a slow fade-out. If the position is close enough to the position stored in the database 134, the corruption rate C (Pc) is retrieved, based on which an appropriate error concealment strategy may be determined. The control module 140 may update the database 134 when the audio signal s1 is corrupted or when the audio signal s1 is lossless again. In this way, if the spatial location is not in database 134, error concealment is conservative, resulting in more silent audio to prevent intermittent audio, while if the spatial location has been previously visited and is therefore in database 134, error concealment is less conservative, resulting in less silent audio.

[0036] Figure 3 An example graph 150 of radio reception condition quality metrics recorded during a test drive is shown. The y-axis Q shows the bit error rate (BER) of the Fast Information Channel (FIC) of the DAB+ broadcast varying between 0 and 0.08. The x-axis shows the time between 0 and 600 seconds corresponding to the position variation as the vehicle moves. A high BER factor indicates a high probability of audio signal corruption. Referring to line 152, it can be observed that the BER is below 0.025 most of the time in a section roughly between t=500s and t=530s, wherein the BER is generally above 0.025 except for a short section with a low BER factor in the middle.

[0037] Figure 4A graph 160 is shown which shows a portion of graph 150, with an additional region 164 showing when audio signal corruption actually occurs. Although the FIC BER line 162 indicates audio signal corruption, it is difficult to correlate that measure with actual signal corruption: audio signal drops do not always correspond to high FIC BER values, or vice versa. It can be observed that the first audio signal corruption occurs around t=500s, and the audio recovers twice shortly thereafter. This is an example of intermittent audio, which is to be avoided because it is considered annoying. The audio signal recovers at about t=514s, but only for about 1 second, even though the FIC BER is relatively low in that segment. This behavior is consistent, and it is associated with the spatial location when the vehicle enters a short tunnel during this segment.

[0038] By storing problem locations (with corresponding damage rates and broadcasts from driving history), error concealment can be controlled so that the audio remains absent until the tunnel ends. The database size is limited and may not retain all locations that have been visited. In one example, only recent information can be retained by sorting the entries by date and retaining only the more recent entries. In this way, locations that have not been visited for a long time are deleted (moved out) from the database. In other examples, information about frequently visited locations can be retained by storing information about the number of times the location was visited in the past month or year. If this number is high enough, then the entry is retained. Dynamically updating the database 134 avoids having to use a fixed database that would need to contain a very high resolution map for each broadcast. This is because audio signal degradation is different for different tuner frequencies and even for different channels in the same multiplex.

[0039] In mobile radios, such as car radio systems, reception quality may vary along a given route, but in a fairly consistent manner. When commuting to work, for example, there may be multiple locations where audio data is consistently corrupted. Typical error concealment systems will consistently fade the audio signal in and out or mix another broadcast too conservatively, since there is no prior or accumulated knowledge about audio degradation. This can become particularly annoying when it occurs in specific locations on a daily route.

[0040] Some examples use radio reception condition metrics to predict when audio corruption will occur. However, due to the fault tolerance in digital radio standards, a moderate degree of antenna signal degradation will not result in audio signal corruption. Indications of impending audio corruption can be obtained from the tuner, OFDM demodulator, and (channel and source) decoder stages, and audio fade-out can be initiated when there is an indication of expected audio corruption. However, this may result in muting the audio signal, even when there is no audio signal corruption.

[0041] After the fade out, when the audio data becomes lossless again, the audio signal can be faded in. This is usually done with a reasonable confidence that the audio data will remain lossless for a considerable time to avoid intermittent audio. Therefore, a safety period is required in which the audio signal is evaluated before initiating the audio fade in. If this safety period is too short, there is a risk of intermittent audio, and when it is too long, the method becomes too conservative.

[0042] In other scenarios, in addition to the main broadcast, simulcast, that is, the secondary broadcast of the same radio program from different sources (e.g., analog broadcast on FM or digital broadcast on Internet radio) is also available. If the audio data of the main broadcast is damaged, the system can "mix" the received audio signal of the secondary broadcast. This usually requires the alignment of the secondary broadcast so that the audio content is closer to the audio content of the main broadcast, for example, in level, frequency and stereoscopic image, so as to make the transition smoother. When the data of the main broadcast is damaged for a long time, the alignment can be gradually removed so that the original secondary broadcast is played. The alignment of the two broadcasts is usually a short-term estimate based on the difference, and may not be effective in a long period of time. However, if the audio is damaged only in a short time, it is better not to remove the alignment, because this may produce audible artifacts. The control of the mixing process is similar to the control of the fade method, and it is necessary to make similar decisions in terms of when to mix the secondary broadcast and when to return to the main broadcast and when to gradually remove the alignment.

[0043] Therefore, the control of error concealment based on the radio reception condition signal can result in an overly conservative error concealment strategy: due to the error correction method in the decoder, a degraded reception quality may still result in a lossless audio signal. As a result, even when the audio signal is lossless, it sometimes starts to fade out. In addition, the fade-in of the audio requires an additional safety period in which the audio signal is evaluated, resulting in a longer period without audio.

[0044] The mobile radio 100 allows the use of a priori knowledge of the broadcast audio signal quality in a particular location so that an appropriate concealment strategy can be selected. The mobile radio 100 may use information from the navigation system to build or adapt a database that can be used to determine an appropriate error concealment strategy.

[0045] Figure 5An error concealment method 200 for a mobile radio (e.g., mobile radio 100) according to an embodiment is shown. In step 202, the method starts. In step 204, a current position is determined, for example, by a GPS receiver. In step 206, the method checks to see if the current position is in a database. If the current position is not in the database, then in step 208, the method checks to see if the audio signal is corrupted. If the audio signal is not corrupted, the method returns to the start (step 202) and error concealment is not applied, i.e., the audio signal is not modified. Otherwise, after step 208, in step 210, the method determines at least one signal quality parameter of the audio signal. After step 210, in step 212, a database is updated with a database entry comprising at least one audio signal parameter and an associated (current) position value. The method then applies a default error concealment method in step 214. The method then ends in step 220. Returning to step 206, if the current position is in the database, then in step 216, one or more associated signal quality parameters are retrieved from the database. In step 218, an error concealment method is selected and applied depending on at least one signal quality parameter.

[0046] Figure 6 An error concealment method 250 for a mobile radio with a single source of a broadcast channel is shown according to an embodiment. In step 252, a current location is received from a spatial location receiver such as a GPS or other receiver. In step 254, the method looks up an audio impairment duration associated with the current location from a database. The audio impairment duration is an example of a signal quality parameter. In step 256, the method determines whether the audio impairment duration is below a first threshold. If the audio impairment duration is below the first threshold, the method proceeds to step 258 and frame repetition of the audio signal is applied. Otherwise, the method proceeds to step 260 and audio fade-in and fade-out are applied.

[0047] Figure 7An error concealment method 300 for a mobile radio with a secondary source of a broadcast channel according to an embodiment is shown. In step 302, a current location is determined. In step 304, the method looks for an audio impairment duration associated with the current location. The audio impairment duration is an example of a signal quality parameter. Step 306 determines whether the audio impairment duration is below a first threshold. If the audio impairment duration is below the first threshold, the method proceeds to step 310 and switches to an aligned secondary broadcast for a first time period, after which the audio output reverts to the primary broadcast. Returning to step 306, if the audio impairment duration is equal to or above the first threshold, the method proceeds to step 312 and determines whether the audio impairment duration is below a second threshold greater than the first threshold. If the audio impairment duration is below the second threshold, the method proceeds to step 314 and switches to an aligned secondary broadcast for a second time period longer than the first time period of step 310. After the second time period, the audio output reverts to the primary broadcast. Returning to step 312, if the audio corruption duration is above or equal to the second threshold, the method proceeds to step 316 and switches to the secondary broadcast aligned for a limited period of time, then removes the alignment. The secondary broadcast is then effectively used as the primary broadcast.

[0048] Figure 8 A method of updating a database 400 for use by embodiments of the error concealment methods and apparatus described herein (e.g., mobile radio 100 and error concealment methods 200, 250, 300) is shown. In step 402, the method begins. In step 404, the method checks to see if the current position is in the database. If the current position is in the database, then in step 406, the timestamp in the database entry is updated for the current position. After step 406, the location access count value of the current position is updated (incremented) in step 408. Returning to step 404, if the current position is not in the database, the method proceeds to step 410 and determines at least one signal quality parameter of the audio signal. In step 412, the current position and the signal quality parameter are added to the database as a new database entry. In step 414, the timestamp is added to the newly created database entry.

[0049] From steps 408 and 414, the method proceeds to step 416, which checks whether the number of database entries (database size) exceeds a predefined limit. If it does not exceed the limit, the method ends in step 422. Otherwise, in step 418, one or more entries with the oldest timestamp value may be removed. In step 420, one or more entries may be removed based on the least visited locations (i.e., the smallest location visit count value). After step 420, the method ends at step 422. In some examples, steps 406, 414, and 418 may be omitted, i.e., timestamps are not used. In other examples, steps 408 and 420 may be omitted, i.e., location popularity is not used.

[0050] The described embodiments use knowledge about audio signal corruption, which may be related to spatial position obtained from a navigation module. This knowledge may improve error concealment by, for example, preventing intermittent audio by enforcing audio muting when necessary, and fading the audio earlier in the presence of a priori knowledge that the audio is expected to remain lossless. This avoids the use of conservative audio error concealment strategies that may be configured to be overly conservative, such that intermittent audio (short segments where audio is present / absent) is avoided, for example, by muting the audio for longer periods than necessary.

[0051] An error concealment method and apparatus for mobile radio is described herein. A current position value is provided by a spatial position receiver. If available, a signal quality parameter associated with the current position value is retrieved from a database. If the signal quality parameter is available, a first error concealment method for a received audio signal is selected and applied depending on the signal quality parameter value. If the signal quality parameter associated with the current position value is not available and the received audio signal is corrupted, a more conservative second (default) error concealment method is applied to the received audio signal.

[0052] In some example embodiments, the instruction set / method steps described above are implemented as functions and software instructions embodied as an executable instruction set, which is implemented on a computer or a machine programmed and controlled with the executable instructions. Such instructions are loaded for execution on a processor (e.g., one or more CPUs). The term processor includes a microprocessor, a microcontroller, a processor module or subsystem (including one or more microprocessors or microcontrollers), or other control or computing devices. A processor may refer to a single component or multiple components.

[0053] In other examples, the instruction sets / methods shown herein and the data and instructions associated therewith are stored in corresponding storage devices, which are implemented as one or more non-transitory machine or computer readable or computer usable storage media. Such computer readable or computer usable storage media are considered to be part of an article (or product). An article or product may refer to any manufactured single component or multiple components. Non-transitory machine or computer usable media as defined herein do not include signals, but such media may be able to receive and process information from signals and / or other transient media.

[0054] Example embodiments of the materials discussed in this specification may be implemented in whole or in part via a network, computer or data-based device and / or service. These may include the cloud, the Internet, an intranet, a mobile device, a desktop computer, a processor, a lookup table, a microcontroller, a consumer device, an infrastructure, or other enabling devices and services. As may be used herein and in the claims, the following non-exclusive definitions are provided.

[0055] In one example, one or more instructions or steps discussed herein are automated. The term automation or automatically (and similar variations thereof) means the use of computers and / or mechanical / electrical devices to control the operation of a device, system, and / or process without human intervention, observation, effort, and / or decision making.

[0056] Although the attached claims are directed to specific feature combinations, it should be understood that the scope of the disclosure of the present invention also includes any novel feature or any novel feature combination or any generalized form thereof disclosed explicitly or implicitly herein, regardless of whether it relates to the same invention as currently claimed in any claim or whether it alleviates the same technical problem as any or all of the technical problems alleviated by the present invention.

[0057] The applicants hereby give notice that new claims may be formulated to such features and / or combinations of such features during the prosecution of the present application or of any further application derived therefrom.

[0058] For the sake of completeness, it is also stipulated that the term "comprising" does not exclude other elements or steps, the term "a" does not exclude a plurality, a single processor or other unit may fulfil the functions of several components recited in the claims, and the reference signs in the claims should not be construed as limiting the scope of the claims.

Claims

1. A method for error concealment of an audio signal for mobile radio, characterized in that The method comprises: Receive the current position value provided by the spatial position receiver; determining whether at least one signal quality parameter associated with the current position value is available in a database; In response to the at least one signal quality parameter being available: selecting a first error concealment method for the received audio signal in dependence on the at least one signal quality parameter; applying the first error concealment method to the received audio signal; and in response to the at least one signal quality parameter being unavailable, determining that the received audio signal is corrupted: A second error concealment method is applied to the received audio signal.

2. The method according to claim 1, characterized in that The at least one signal quality parameter comprises an audio impairment duration.

3. The method according to claim 2, characterized in that In response to the audio impairment duration being below a first time threshold, the first error concealment method includes frame repetition, or switching to a secondary broadcast signal aligned with the received audio signal in at least one of time, spectrum, and level.

4. The method according to claim 2, characterized in that: In response to the audio corruption duration being above a second time threshold, the first error concealment method comprises at least one of audio fading in and audio fading out, or switching to a secondary broadcast signal and fading out at least one of aligning the spectrum and level of the received audio signal.

5. A method according to any of the preceding claims, characterised in that The at least one signal quality parameter comprises an audio corruption rate.

6. A method according to any of the preceding claims, characterised in that Also included is updating a database comprising a plurality of database entries, each database entry comprising a position value and a signal quality parameter.

7. The method according to claim 6, characterized in that Additionally comprising, in response to the at least one signal quality parameter being unavailable: determining the at least one signal quality parameter of the received audio signal; and updating the database with a database entry comprising the at least one signal quality parameter and the current position value.

8. The method according to claim 6 or 7, characterized in that: Each database entry additionally includes at least one of a timestamp value and a location visit count value, and the method additionally includes updating the database with at least one of the timestamp value and the location visit count value for the current location.

9. A controller for a mobile radio, characterized in that The controller comprises: a navigation input configured to couple to a spatial position receiver; a radio reception condition input configured to receive a radio reception condition signal; an audio input configured to be coupled to an output of a radio receiver; and Audio output; The controller is configured to: Receive the current position value provided by the spatial position receiver; determining whether at least one signal quality parameter associated with the current position value is available in a database; In response to the at least one signal quality parameter being available: selecting a first error concealment method for the received audio signal in dependence on the at least one signal quality parameter; applying the first error concealment method to the received audio signal; and In response to the at least one signal quality parameter being unavailable, the controller is further configured to: predicting whether the received audio signal will be corrupted based on the radio reception condition signal; and In response to determining that the received audio signal will be corrupted, a second error concealment method is applied to the received audio signal.

10. The controller according to claim 9, characterized in that: Also includes: a control module coupled to the database, the control module having a first control module input coupled to the navigation input, a second control module input coupled to the radio reception condition input, and a control module output; an error concealment module having a first error concealment input coupled to the audio input, a second error concealment input coupled to the control module output, and an error concealment output coupled to the audio output; The control module is configured to: receiving the current position value; determining whether at least one signal quality parameter associated with the current position value is available in the database; In response to the at least one signal quality parameter being available: selecting a first error concealment method for the received audio signal in dependence on the at least one signal quality parameter; controlling the error concealment module to apply the first error concealment method to the received audio signal; In response to the at least one signal quality parameter being unavailable: determining whether the received audio signal will be corrupted based on the radio reception condition signal; The error concealment module is controlled to apply the second error concealment method to the received audio signal.

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