SYSTEM AND METHOD FOR GROUP PROBABILITY-BASED PREFIX MODIFICATION OF UNKNOWN SYMBOL PROBABILITY DISTRIBUTIONS

A method may include receiving a first symbol, and encoding the first symbol based on an initial codebook including a symbol frequency and a ranking for each symbol, and a group frequency for each group of symbols. The method may include incrementing a symbol frequency of the first symbol based on receiving the first symbol, swapping a rank of a lowest ranking symbol from among symbols in the initial codebook that have a symbol frequency lower than the incremented symbol frequency of the first symbol with a rank of the first symbol, in response to the symbol frequency of the lowest ranking symbol being lower than the incremented symbol frequency of the first symbol, and storing an updated codebook in a memory accessible by an encoder and/or a decoder.

FIELD

The disclosure generally relates to entropy coding. More particularly, the subject matter disclosed herein relates to improvements to a system and a method for group probability-based prefix modification of unknown symbol probability distributions.

SUMMARY

In digital signal processing, data (which may also be referred to as a “symbol”) is often encoded (e.g., into binary bits) by an encoder before being transmitted by a transmitter, and then decoded by a decoder upon receiving the encoded signal by a receiver. Electronic devices such as cellular phones, televisions, and other audio or video devices often utilize such digital signals when transmitting them between one device and another and/or even within the device itself, for example, transmitting a digital signal from one part of the device to another part of the same device. To effectively and efficiently transmit the digital signal, the encoding process may include compressing the digital signal such that fewer number of bits may be used to represent the original data.

Entropy encoding is a coding technique for digital signal processing that assigns a binary code to a symbol based on a probability of occurrence of that symbol. Some entropy coding techniques use binary code that can be represented by a combination of prefix and suffix, where the prefixes may be unique and the corresponding suffixes may have a fixed length. In the present disclosure, these codes may be referred to as prefix-suffix entropy codes and may include entropy codes such as, exponential Golomb codes, Elias gamma/delta/omega codes, Levenstein codes, etc.

One or more embodiments of the present disclosure may describe techniques to further optimize the entropy encoding.

According to a first embodiment of the present disclosure, a method may include: receiving, by an encoder, a first symbol; encoding, by the encoder, the first symbol based on an initial codebook including a symbol frequency and a ranking for each symbol, and a group frequency for each group of symbols; incrementing a symbol frequency of the first symbol based on receiving the first symbol; swapping a rank of a lowest ranking symbol from among symbols in the initial codebook that have a symbol frequency lower than the incremented symbol frequency of the first symbol with a rank of the first symbol, in response to the symbol frequency of the lowest ranking symbol being lower than the incremented symbol frequency of the first symbol; and storing an updated codebook in a memory accessible by the encoder.

The method may further include updating group frequencies based on the incremented symbol frequency of the first symbol and the swapping.

The method may further including: determining that a first group frequency of a first group is lower than a second group frequency of a second group; and swapping a first prefix corresponding to the first group with a second prefix corresponding to the second group in response, wherein a rank of the first group is lower than a rank of the second group.

The method may further include transmitting the encoded first symbol to a decoder in response to the encoder receiving the first symbol.

The first symbol may be encoded based on the initial codebook, the encoding being an entropy encoding.

The storing the updated codebook may include replacing the initial codebook in the memory with the updated codebook.

The symbol frequencies and group frequencies may be reset to zero in the initial codebook.

The initial codebook may be based on exponential Golomb codebook.

The initial codebook may include prefix-suffix codewords corresponding to symbols.

According to a second embodiment of the present disclosure, a method may include: receiving, by a decoder, a first code word; decoding, by the decoder, the first code word based on an initial codebook including a symbol frequency and a ranking for each symbol, and a group frequency for each group of symbols; incrementing a symbol frequency of a first symbol decoded from the first code word; swapping a rank of a lowest ranking symbol from among symbols in the initial codebook that have a symbol frequency lower than the incremented symbol frequency of the first symbol with a rank of the first symbol, in response to the symbol frequency of the lowest ranking symbol being lower than the incremented symbol frequency of the first symbol; and storing an updated codebook in a memory accessible by the decoder.

The method may further include updating group frequencies based on the incremented symbol frequency of the first symbol and the swapping.

The method may further include: determining that a first group frequency of a first group is lower than a second group frequency of a second group; and swapping a first prefix corresponding to the first group with a second prefix corresponding to the second group in response, wherein a rank of the first group is lower than a rank of the second group.

The first symbol may be decoded based on the initial codebook, the decoding being an entropy decoding.

The storing the updated codebook may include replacing the initial codebook in the memory with the updated codebook.

The symbol frequencies and group frequencies may be reset to zero in the initial codebook.

The initial codebook may be based on exponential Golomb codebook.

The initial codebook may include prefix-suffix codewords corresponding to symbols.

According to a third embodiment of the present disclosure, a system may include: a memory; and a processor configured to execute instructions stored in the memory to perform operations including: receiving a first symbol; encoding the first symbol based on an initial codebook including a symbol frequency and a ranking for each symbol, and a group frequency for each group of symbols; incrementing a symbol frequency of the first symbol based on receiving the first symbol; swapping a rank of a lowest ranking symbol from among symbols in the initial codebook that have a symbol frequency lower than the incremented symbol frequency of the first symbol with a rank of the first symbol, in response to the symbol frequency of the lowest ranking symbol being lower than the incremented symbol frequency of the first symbol; and storing an updated codebook in a memory accessible by the encoder.

The operations may further include updating group frequencies based on the incremented symbol frequency of the first symbol and the swapping.

The operations may further include: determining that a first group frequency of a first group is lower than a second group frequency of a second group; and swapping a first prefix corresponding to the first ranked group with a second prefix corresponding to the second group in response, wherein a rank of the first group is lower than a rank of the second group.

DETAILED DESCRIPTION

In one or more embodiments of the present disclosure, techniques will be described to further reduce the number of bits utilized by these prefix-suffix entropy codes.FIG.1is a table that illustrates an example codebook for 256 symbols using truncated exponential Golomb codes. The symbols may be represented as s0-s255and grouped into 8 groups, 0-7. Furthermore, it is assumed that the probability or frequency (i.e., probability or frequency of occurrence) of s0is higher than or equal to the probability of s1. Therefore, for example, the probability of s1is higher than or equal to the probability of s2, the probability of s2is higher or equal to the probability of s3, and so on. It should be noted that although the codebook shown inFIG.1includes 256 symbols, a codebook may instead include fewer or greater symbols, for example, 16 symbols, 512 symbols, 1024 symbols, etc. As shown inFIG.1, a group of symbols may be sorted or assigned to a group, and each group may have a unique prefix that is shared by all symbols in that group. Thus, for example, all symbols in group 0 (i.e., symbols s0-s1) have a prefix 0, all symbols in group 1 (i.e., symbols s2-s5) have a prefix 10, and all symbols in group 2 (i.e., symbols s6-s13) have a prefix 110, and so on. However, the suffixes for each symbol are unique to each symbol even if the symbols are in the same group. Accordingly, every symbol has a unique binary code. Furthermore, although each suffix is unique, the suffixes for the symbols belonging to the same group are all made up of the same number of bits. In other words, the bit length of the suffix is the same for all symbols in the same group. For example, the suffix for all of the symbols in group 0 have a length of 1 (i.e., 1 bit), the suffix for all of the symbols in group 1 have a length of 2 (i.e., 2 bits), the suffix for all of the symbols in group 2 have a length of 3 (i.e., 3 bits), and so on.

Additionally, the suffixes for the symbols are sequential such that the first symbol in a particular group has a suffix corresponding to a first binary number in that group and the last symbol in that particular group has a suffix corresponding to the last binary number in that group. For example, in group 0, s0is the first symbol so the corresponding suffix is 0 and s1is the last symbol in this group so that corresponding suffix is 1. In group 1, s2is the first symbol so the corresponding suffix is 00, s3is the second symbol so the corresponding suffix is 01, s4is the third symbol so the corresponding suffix is 10, and s5is the fourth (and the last) symbol of this group so the corresponding suffix is 11. Thus, the binary code for the symbol is the combination of the prefix and the suffix as shown in the table. For example, the code for symbol s0is 00 (i.e., prefix=0; suffix=0), and the code for symbol s1is 01 (i.e., prefix=0; suffix=1).

However, these prefix-suffix codes assume a certain probability distribution for the symbols. For example, exponential Golomb codes assume that the symbols have a geometric distribution. Therefore, these codes may perform most effectively if the symbols have an actual geometric distribution. However, exponential Golomb codes may be used on data that may not necessarily have a geometric distribution, thus leading to suboptimal binary codes. The same can be said for other prefix-suffix coding techniques, such as Elias gamma/delta/omega codes whereby these code assume a certain probability distribution but the actual distribution may be different. Accordingly, it is desirable to improve such entropy coding techniques to better fit actual probability distribution of the symbols. However, the actual probability distribution of the symbols may not necessarily be known thereby making it difficult to find better coding methods. Therefore, one or more embodiments of the present disclosure are directed to dynamically modifying an existing codebook based on the frequency of occurrence of the symbols received such that the codebook is updated on-the-fly with actual probability distribution as the incoming data (or symbols) are received. Accordingly, the codebook may be updated in real-time by learning the actual probability distribution of the symbols as the symbols are received, thereby optimizing the entropy encoded binary codes. Furthermore, as the probability distribution of the symbols change, the code book may continue to be updated based on the new probability distribution. As a result, the symbols can change from one group to another on an on-going basis. Furthermore, the modification of the codebook according to various embodiments of the present disclosure may also be implemented by the decoder in real-time so that the decoder may decode the received binary code.

In one or more embodiments of the present disclosure, as the codebook is updated, only the prefixes, only the suffixes, or both the prefixes and the suffixes of these prefix-suffix coding techniques may be modified such that the assignment of the binary codes to the symbols is more optimal for the actual probability distribution of the symbols.

FIG.2illustrates an example codebook that may be modified according to one or more embodiments of the present disclosure. Similar to the table illustrated inFIG.1, the table inFIG.2represents a truncated exponential-Golomb codebook except only 16 symbols are listed for simplicity in explaining the techniques of the present disclosure. However, as noted above, the one or more embodiments of the present disclosure may be applied to codebooks that include more or fewer symbols.

Here, the codebook lists 16 symbols s0-s15and their corresponding symbol frequencies (e.g., frequency of occurrence of the symbol), ranking of the symbols based on the frequencies, a grouping of the symbols and their corresponding group frequencies (e.g., frequency of occurrence of the symbol in the group), and the corresponding prefixes and suffixes for the symbols. More specifically, for the purpose of this example codebook, symbols so and s1are in group 0, symbols s2-s5are in group 1, symbols s6-s7are in group 2, and symbol s15is in group 3. Furthermore, a prefix of 0 and a suffix of 0 corresponds to symbol so; a prefix of 0 and a suffix of 1 corresponds to symbol s1; a prefix of 10 and a suffix of 00 corresponds to symbol s2; a prefix of 10 and a suffix of 01 corresponds to symbol s3; a prefix of 10 and a suffix of 10 corresponds to symbol s4; a prefix of 10 and a suffix of 11 corresponds to symbol s5; a prefix of 110 and a suffix of 000 corresponds to symbol s6; a prefix of 110 and a suffix of 001 corresponds to symbol s7; and a prefix of 111 and a suffix of 0001 corresponds to symbol s15, by way of example. Because this codebook shows the initial state of the codebook, all symbol frequencies are initialized to a frequency of zero and all group frequencies are initialized to a frequency of zero. As the encoder receives incoming data, the symbol frequencies may be updated, which in turn may update the group frequencies. Therefore, the symbols can move from one group to another group, the symbol rankings may change, and the group prefixes may be modified based on the symbol switching and the group frequencies (or probabilities). These steps will be described in further detail.

Here in the present disclosure, firepresents the frequency of symbol siand rirepresents its rank. Therefore, fjis the frequency of symbol sjand rjis its rank. Thus, if fi≥fjthen ri<rj. In other words, the higher the frequency of occurrence (or higher probability of occurrence), the smaller the rank. One or more embodiments of the present disclosure will be described by assuming that symbols are received by the encoder (for encoding and then transmission) in the following order: s0, s0, s1, s2, s6, s4, s5, s6. Therefore, according to a first step, when the first symbol s0is received by the encoder, the encoder may transmit the prefix-suffix code 00. Here, based on the initialized codebook (e.g., the codebook inFIG.2), the prefix-suffix code for so corresponds to a prefix of 0 and a suffix of 0. Therefore, the prefix-suffix code 00 is sent to the decoder. Furthermore, at the encoder, the symbol frequency for so may be incremented by 1 because the encoder received so one time. In other words, there was one occurrence of the symbol so. At this time, so has the highest frequency out of all of the symbols that are in the codebook and has a default (or initial) rank value of 0, which is the lowest rank. Therefore, the prefix portion of the codebook is not updated. However, because the symbol frequency for so was incremented, the group frequency for group 0 (which is the group that so belongs) is also incremented.

Next, the encoder receives a second symbol, which is again s0so the same prefix-suffix code 00 is sent to the decoder, and the symbol frequency for s0is incremented by 1. Therefore, the symbol frequency for s0is now 2, and is the highest symbol frequency of all symbols in the codebook. Because so already has the lowest (or smallest) rank 0, the codebook is correct in its current state and no further updates are made to the codebook. However, the group frequency for group 0 is also incremented by 1 to now have a value of 2 because the symbol frequency was incremented.

Next, the encoder receives a third symbol s1, so the prefix-suffix code 01 is sent to the decoder and the symbol frequency for s1is incremented by 1. Therefore, the symbol frequency for s1is 1. Because s1now has the second highest symbol frequency and the second lowest rank of 1, the codebook is correct in its current state and no further updates are made to the codebook. In other words, out of all of the symbol frequencies in the codebook that are lower than the symbol frequency corresponding to s1(i.e., any symbol frequency that is less than 1), the symbol frequency of s1is the lowest rank so no further updates are made to the codebook. However, because the symbol frequency was updated, the group frequency of group 0 is incremented by 1 so that it now has a value of 3.FIG.3shows the status of the codebook after the first three symbols s0, s0, s1are received and the codebook is updated. As can be seen, the group frequency is the total of the symbol frequencies in that particular group.

Next, the encoder receives a fourth symbol, which is s2, so the prefix-suffix code 1000 is sent to the decoder, and the symbol frequency for s2is incremented by 1. Because s2has the same symbol frequency as s1but has a higher rank of 2, the prefix portion of the codebook is not updated. However, the group frequency for group 1 is incremented by 1 because s2is in group 1.

Next, the encoder receives a fifth symbol, which is s6, so the prefix-suffix code 110000 is sent to the decoder, and the symbol frequency for s6is incremented by 1. Now, because s6has a higher symbol frequency than symbols s3, s4, s5(which have a symbol frequency of 0) but also has a higher rank than symbols s3, s4, s5, the rank of s6is swapped with s3, which is the lowest ranked symbols out of s3, s4, s5. Therefore, the rank of symbol s6is elevated to rank 3 and as a result, s6is moved to group 1, and the rank of symbol s3is now downgraded to rank 6 and is moved to group 2. Based on this new ranking and new grouping, the group frequency of group 1 (i.e., the new group corresponding to s6) is updated. Accordingly, group 1 now has a group frequency of 2.FIG.4shows the status of the codebook after the first five symbols s0, s0, s1, s2, s6are received and the codebook is updated.

Next, the encoder receives a sixth symbol, which is s4, so the prefix-suffix code 1010 is sent to the decoder, and the symbol frequency for s4is incremented by 1. Because s4has a lower rank than the other symbols that have a lower symbol frequency than s4(i.e., s3, s5, s7, s15which all have a symbol frequency of 0), the ranking is not updated. The group frequency for group 1 is incremented by 1 and now has a value of 3. Group 1 and group 0 now have the same group frequency of 3 so the prefix portion of the codebook is not updated.

Next, the encoder receives a seventh symbol, which is s5, so the prefix-suffix code 1011 is sent to the decoder, and the symbol frequency for s5is incremented by 1. Because s5has a lower rank than the other symbols that have a lower symbol frequency than s5(i.e., s3, s7, s15which all have a symbol frequency of 0), the ranking is not updated. The group frequency for group 1 is incremented by 1 and now has a value of 4. Now, because the group frequency for group 1 is higher than the group frequency of group 0, a group frequency inversion exists. In other words, a group frequency inversion exists when the group frequency of a higher ranked group (i.e., higher rank number) has a higher group frequency than the group frequency of a lower ranked group (i.e., lower rank number). Because of the presence of the group frequency inversion, the prefixes of group 0 and group 1 are swapped. Accordingly, group 0 now has a prefix 10 and group 1 has a prefix 0.FIG.5shows the status of the codebook after the first seven symbols s0, s0, s1, s2, s6, s4, s5are received and the codebook is updated. In the present disclosure, the terms “inversion” or “probability inversion” may be defined as a condition when given Px and Py, where Px>Py but Px appears after Py in a given string of probabilities.

Finally, the encoder receives the eighth symbol, which is s6, so the prefix-suffix code 001 is sent to the decoder, and the symbol frequency for s6is incremented by 1. As can be seen fromFIG.5, the binary code for s6is much shorter (i.e., 010) than the binary code for s6in the codebook at initialization (i.e., 110000). The symbol frequency for s6now has a value 2, and therefore has a higher symbol frequency than s1, s2, while still having a higher rank than s1, s2. Therefore, the rank of symbol s6is swapped with the rank of s1because s1has the lowest rank among s1, s2. As a result, symbol s6is elevated to rank 1 and is assigned to group 0. Consequently, the group frequency of group 0 is updated to 4 accordingly. Because the group frequencies of group 0 and 1 are the same, no update to the codebook (i.e., no update to the prefix) is performed. Accordingly, this completes the process for updating the codebook based on the example 8 symbols described herein. As additional symbols are received by the encoder, the same process may be performed and the codebook may continue to be updated in real-time.

In one or more embodiments of the present disclosure, as the above provided example symbols are encoded by the encoder, the bitstream 000001100011000010101011001 is transmitted to a receiver including a decoder. As with the encoder, the decoder may also include the same initial codebook as the initial codebook used by the encoder. By utilizing this initialized codebook, the decoder may decode 00 from the bitstream to determine that the first symbol is s0. The symbol frequency and group frequency are updated accordingly in the same manner as described above in the encoder for the first received symbol. Therefore, in this case, after the first symbol s0is received, the symbol frequency for s0is incremented and the group frequency for group 0 is incremented, while prefix for the codebook does not change. Accordingly, the decoder codebook may be updated to have an identical codebook as the one modified at the encoder thereby being more aligned with the actual probability distribution.

The decoder may next decode 00 from the bitstream 000001100011000010101011001 to determine that the next symbol is again s0. Accordingly, the symbol frequency and group frequency are updated again and the prefix of the codebook remains unchanged.

Next, the decoder may decode 01 from the bitstream 000001100011000010101011001 to determine that the next symbol is s1, and the symbol frequency and the group frequency are updated again while the codebook remains unchanged.

Next, the decoder may decode 1000 from the bitstream 000001100011000010101011001 to determine that the next symbol is s2, followed by decoding 110000 from the bitstream to determine that the next symbol is s6. In the same manner as in the encoder, after symbol s6is received by the decoder, the rank of symbol s6is updated by swapping with rank of symbol s3. The modified codebook is identical to the codebook that was modified by the encoder as shown inFIG.4. Thus, the codebook used by the decoder is in sync with the encoder and therefore proper decoding may be performed.

FIG.7is a flow chart illustrating a method for modifying an initialized codebook of an encoder and a decoder according to one or more embodiments of the present disclosure. At step702, an encoder may receive one or more symbols that are to be encoded. At step704, the encoder may encode a first symbol of the received one or more symbols based on an initial codebook comprising a symbol frequency and a ranking for each symbol, and a group frequency for each group of symbols. In other words, the encoder may utilize the encoder codebook to entropy encode the symbol into code word that has prefix bits and suffix bits (referred to herein as prefix-suffix code words) that correspond to the symbol frequency, rankings for the symbols, and group frequency for groups of symbols. This codebook may be referred to as the initial codebook or a default codebook because this is the codebook that is provided when this encoding process started and before any modifications are made to the codebook. After the symbols are encoded by the encoder, the encoded code words may be transmitted or sent to the decoder.

After the first symbol is received and the first symbol is encoded, the symbol frequency of the first symbol may be incremented at step706. In some embodiments, a rank of the lowest ranking symbol from among symbols in the initial codebook that have a symbol frequency lower than the incremented symbol frequency of the first symbol may be swapped with a rank of the first symbol. In other words, the ranks are swapped if the rank of lowest ranking symbol (i.e., the lowest ranking symbol out of the set of symbols that have a frequency of occurrence that is less than the frequency of occurrence of the first symbol) is smaller in value than the rank of the first symbol (i.e., the symbol that was received by the encoder and then incremented).

In some embodiments, a group frequency corresponding to a group comprising the first symbol may be updated based on the incremented symbol frequency of the first symbol. Additionally, the group frequencies corresponding to the groups that include symbols where the rankings were swapped, are also updated at step708. Next, a determination is made whether a first group frequency of a first group is lower than a second group frequency of a second group, and if so, a first prefix corresponding to the first group may be swapped with a second prefix corresponding to the second group at step710. It should be noted here that the rank of the first group is lower (e.g., a smaller number) than the rank of the second group. However, if the first group frequency of a first group is not lower than a second group frequency of a second group, then the prefix is not swapped. Finally, the updated codebook may be stored in a memory that is accessible by the encoder so that the encoder can use the updated codebook. In some embodiments, when the updated codebook is stored in the memory, the initial codebook may be erased or overwritten by the newly modified codebook. Therefore, when the next symbols are received by the encoder, the modified codebook is utilized as the next default codebook. Accordingly, this process may continue such that the codebook is continuously updated based on the received symbols in real-time.

Next, the processes for updating the codebook on the decoder side will be described. At step712, the code words (i.e., encoded bits) sent from the encoder are received by the decoder. At step714, the decoder may decode the received first code word based on an initial codebook that maps code words to symbols, and includes a symbol frequency and a ranking for each symbol, and a group frequency for each group of symbols. This initial codebook includes the same table that the encoder utilized to entropy encode the symbols, and therefore the decoder is able to correctly decode the code words to generate the symbol that was originally encoded by the encoder. Accordingly, the decoded symbol may now be outputted from the decoder and utilized by the system, such as for example, a computer system.

At step716, once the code word is decoded and a first symbol is generated, a symbol frequency of a first symbol decoded from the first code word may be incremented. Note that this is similar to the process that occurred on the encoder side where the first symbol frequency was incremented. Additionally, a rank of the lowest ranking symbol from among symbols in the initial codebook that have a symbol frequency lower than the incremented symbol frequency of the first symbol may be swapped with the rank of the first symbol. In other words, the ranks are swapped if the rank of lowest ranking symbol (i.e., the lowest ranking symbol out of the set of symbols that have a frequency of occurrence that is less than the frequency of occurrence of the first symbol) is smaller in value than the rank of the first symbol (i.e., the symbol that was received by the encoder and then incremented).

In some embodiments, a group frequency corresponding to a group comprising the first symbol may be updated based on the incremented symbol frequency of the first symbol. Additionally, the group frequencies corresponding to the groups that include symbols where the rankings were swapped, are also updated at step718. A determination may be made as to whether a first group frequency of a first group is lower than a second group frequency of a second group, and if so, a first prefix corresponding to the first group may be swapped with a second prefix corresponding to the second group at step720. It should be noted here that the rank of the first group is lower (e.g., a smaller number) than the rank of the second group. However, if the first group frequency of a first group is not lower than a second group frequency of a second group, then the prefix is not swapped. Finally, the updated codebook may be stored in a memory that is accessible by the decoder so that the decoder can use the updated codebook. When the updated codebook is stored in the memory, the initial codebook may be erased or overwritten by the newly modified codebook. Accordingly, the updated codebook for the decoder is updated in real-time in the same manner as the updated codebook for the encoder.

Accordingly, as the number of prefixes is much smaller compared to the number of symbols, updating the prefixes does not add significant overhead to the computer and therefore a more improved efficiency may be achieved. Moreover, symbol switching coupled with group prefix modification gives an extra layer of flexibility to the dynamic algorithm, and one or more prefix-suffix codes designed for any probability model may be modified to best fit the probability distribution of the actual symbols and groups.

FIG.8is a block diagram of an electronic device in a network environment800, according to an embodiment.

Referring toFIG.8, an electronic device801in a network environment800may communicate with an electronic device802via a first network898(e.g., a short-range wireless communication network), or an electronic device804or a server808via a second network899(e.g., a long-range wireless communication network). The electronic device801may communicate with the electronic device804via the server808. The electronic device801may include a processor820, a memory830, an input device850, a sound output device855, a display device860, an audio module870, a sensor module876, an interface877, a haptic module879, a camera module880, a power management module888, a battery889, a communication module890, a subscriber identification module (SIM) card896, or an antenna module897. In one embodiment, at least one (e.g., the display device860or the camera module880) of the components may be omitted from the electronic device801, or one or more other components may be added to the electronic device801. Some of the components may be implemented as a single integrated circuit (IC). For example, the sensor module876(e.g., a fingerprint sensor, an iris sensor, or an illuminance sensor) may be embedded in the display device860(e.g., a display).

The processor820may execute software (e.g., a program840) to control at least one other component (e.g., a hardware or a software component) of the electronic device801coupled with the processor820and may perform various data processing or computations.

As at least part of the data processing or computations, the processor820may load a command or data received from another component (e.g., the sensor module876or the communication module890) in volatile memory832, process the command or the data stored in the volatile memory832, and store resulting data in non-volatile memory834. The processor820may include a main processor821(e.g., a central processing unit (CPU) or an application processor (AP)), and an auxiliary processor823(e.g., a graphics processing unit (GPU), an image signal processor (ISP), a sensor hub processor, or a communication processor (CP)) that is operable independently from, or in conjunction with, the main processor821. Additionally or alternatively, the auxiliary processor823may be adapted to consume less power than the main processor821, or execute a particular function. The auxiliary processor823may be implemented as being separate from, or a part of, the main processor821.

The auxiliary processor823may control at least some of the functions or states related to at least one component (e.g., the display device860, the sensor module876, or the communication module890) among the components of the electronic device801, instead of the main processor821while the main processor821is in an inactive (e.g., sleep) state, or together with the main processor821while the main processor821is in an active state (e.g., executing an application). The auxiliary processor823(e.g., an image signal processor or a communication processor) may be implemented as part of another component (e.g., the camera module880or the communication module890) functionally related to the auxiliary processor823.

The memory830may store various data used by at least one component (e.g., the processor820or the sensor module876) of the electronic device801. The various data may include, for example, software (e.g., the program840) and input data or output data for a command related thereto. The memory830may include the volatile memory832or the non-volatile memory834. Non-volatile memory834may include internal memory836and/or external memory838.

The program840may be stored in the memory830as software, and may include, for example, an operating system (OS)842, middleware844, or an application846.

The input device850may receive a command or data to be used by another component (e.g., the processor820) of the electronic device801, from the outside (e.g., a user) of the electronic device801. The input device850may include, for example, a microphone, a mouse, or a keyboard.

The sound output device855may output sound signals to the outside of the electronic device801. The sound output device855may include, for example, a speaker or a receiver. The speaker may be used for general purposes, such as playing multimedia or recording, and the receiver may be used for receiving an incoming call. The receiver may be implemented as being separate from, or a part of, the speaker.

The display device860may visually provide information to the outside (e.g., a user) of the electronic device801. The display device860may include, for example, a display, a hologram device, or a projector and control circuitry to control a corresponding one of the display, hologram device, and projector. The display device860may include touch circuitry adapted to detect a touch, or sensor circuitry (e.g., a pressure sensor) adapted to measure the intensity of force incurred by the touch.

The audio module870may convert a sound into an electrical signal and vice versa. The audio module870may obtain the sound via the input device850or output the sound via the sound output device855or a headphone of an external electronic device802directly (e.g., wired) or wirelessly coupled with the electronic device801.

A connecting terminal878may include a connector via which the electronic device801may be physically connected with the external electronic device802. The connecting terminal878may include, for example, an HDMI connector, a USB connector, an SD card connector, or an audio connector (e.g., a headphone connector).

The haptic module879may convert an electrical signal into a mechanical stimulus (e.g., a vibration or a movement) or an electrical stimulus which may be recognized by a user via tactile sensation or kinesthetic sensation. The haptic module879may include, for example, a motor, a piezoelectric element, or an electrical stimulator. The camera module880may capture a still image or moving images. The camera module880may include one or more lenses, image sensors, image signal processors, or flashes. The power management module888may manage power supplied to the electronic device801. The power management module888may be implemented as at least part of, for example, a power management integrated circuit (PMIC).

The battery889may supply power to at least one component of the electronic device801. The battery889may include, for example, a primary cell which is not rechargeable, a secondary cell which is rechargeable, or a fuel cell.

The communication module890may support establishing a direct (e.g., wired) communication channel or a wireless communication channel between the electronic device801and the external electronic device (e.g., the electronic device802, the electronic device804, or the server808) and performing communication via the established communication channel. The communication module890may include one or more communication processors that are operable independently from the processor820(e.g., the AP) and supports a direct (e.g., wired) communication or a wireless communication. The communication module890may include a wireless communication module892(e.g., a cellular communication module, a short-range wireless communication module, or a global navigation satellite system (GNSS) communication module) or a wired communication module894(e.g., a local area network (LAN) communication module or a power line communication (PLC) module). A corresponding one of these communication modules may communicate with the external electronic device via the first network898(e.g., a short-range communication network, such as BLUETOOTH™, wireless-fidelity (Wi-Fi) direct, or a standard of the Infrared Data Association (IrDA)) or the second network899(e.g., a long-range communication network, such as a cellular network, the Internet, or a computer network (e.g., LAN or wide area network (WAN)). These various types of communication modules may be implemented as a single component (e.g., a single IC), or may be implemented as multiple components (e.g., multiple ICs) that are separate from each other. The wireless communication module892may identify and authenticate the electronic device801in a communication network, such as the first network898or the second network899, using subscriber information (e.g., international mobile subscriber identity (IMSI)) stored in the subscriber identification module896.

The antenna module897may transmit or receive a signal or power to or from the outside (e.g., the external electronic device) of the electronic device801. The antenna module897may include one or more antennas, and, therefrom, at least one antenna appropriate for a communication scheme used in the communication network, such as the first network898or the second network899, may be selected, for example, by the communication module890(e.g., the wireless communication module892). The signal or the power may then be transmitted or received between the communication module890and the external electronic device via the selected at least one antenna.

Thus, when one or more of the electronic devices801,802, or804transmits digital signal to another one or more of the electronic devices801,802, or804, the data (or symbols) that are transmitted may be entropy encoded by utilizing a the codebooks describe above, and then decoded by utilizing the codebooks as also describe above. Such codebooks may be dynamically updated on-the-fly as described according to one or more embodiments of the present disclosure such that the codebook is optimal based on the actual probability distribution of the symbols.

FIG.9shows a system including a UE905and a gNB910, in communication with each other. The UE may include a radio915and a processing circuit (or a means for processing)920, which may perform various methods disclosed herein, e.g., the method illustrated inFIG.1. For example, the processing circuit920may receive, via the radio915, transmissions from the network node (gNB)910, and the processing circuit920may transmit, via the radio915, signals to the gNB910.

Embodiments of the subject matter and the operations described in this specification may be implemented in digital electronic circuitry, or in computer software, firmware, or hardware, including the structures disclosed in this specification and their structural equivalents, or in combinations of one or more of them. Embodiments of the subject matter described in this specification may be implemented as one or more computer programs, i.e., one or more modules of computer-program instructions, encoded on computer-storage medium for execution by, or to control the operation of data-processing apparatus. Alternatively or additionally, the program instructions can be encoded on an artificially-generated propagated signal, e.g., a machine-generated electrical, optical, or electromagnetic signal, which is generated to encode information for transmission to suitable receiver apparatus for execution by a data processing apparatus.

A computer-storage medium can be, or be included in, a computer-readable storage device, a computer-readable storage substrate, a random or serial-access memory array or device, or a combination thereof. Moreover, while a computer-storage medium is not a propagated signal, a computer-storage medium may be a source or destination of computer-program instructions encoded in an artificially-generated propagated signal. The computer-storage medium can also be, or be included in, one or more separate physical components or media (e.g., multiple CDs, disks, or other storage devices). Additionally, the operations described in this specification may be implemented as operations performed by a data-processing apparatus on data stored on one or more computer-readable storage devices or received from other sources.