KR102190816B1 - Method for saving power consumtion by early decoding and apparatus thereof - Google Patents

Abstract

Disclosed is a method and apparatus for reducing power consumption through early decoding. The method includes a process of determining whether a predetermined decoding condition is satisfied in a unit time for decoding during one transmission period, and when the decoding condition is satisfied, decoding a signal received up to the unit time during the transmission period A process of performing and, when the decoding is successful, a process of setting the wireless signal processing unit to a low power mode for the remaining time period of the transmission period, and when the unit time is the last unit time of the transmission period, relation with the decoding condition And performing decoding on the signal received through the wireless signal processing unit until the last unit time of the transmission period without.

Description

Method and device to reduce power consumption through early decoding {METHOD FOR SAVING POWER CONSUMTION BY EARLY DECODING AND APPARATUS THEREOF}

The present invention relates to a method and apparatus for reducing power consumption of a receiver supporting early decoding.

The wireless communication system is implemented based on various technologies for high-speed packet data communication. One of the various techniques is error correction decoding.

In a wireless communication system, a transmitter encodes and transmits information bits of data to be transmitted in a packet unit, and a receiver receives the encoded packet through a wireless channel and decodes it by a decoder to recover the information bits.

The decoder may attempt to decode some signals within one transmission period before receiving all signals corresponding to one transmission period (TTI) of the encoding. However, if the channel condition is good, there is a high probability of successful decoding before all signals of one transmission period are received. In this case, the receiver may perform an unnecessary reception operation on signals in the remaining sections that have not yet been received.

Accordingly, a technique for removing unnecessary reception and decoding operations in decoding a wireless communication system is required.

The present invention provides a method and apparatus for supporting early decoding in a wireless communication system.

The present invention relates to a method and apparatus for reducing power consumption of a receiver supporting early decoding.

The present invention provides a method and apparatus for controlling a receiver circuit according to the operation of a digital error correction decoder.

The present invention provides a method and apparatus for reducing power consumption of a wireless terminal by controlling a receiver circuit according to a successful decoding.

The present invention provides a method and apparatus for determining an early decoding time of a digital error correction decoder.

The present invention provides a method and apparatus for controlling the early decoding operation of a digital error correction decoder.

The method according to an embodiment of the present invention; In the power consumption reduction method through early decoding, the process of determining whether a predetermined decoding condition is satisfied in a unit time for decoding during one transmission period, and, when the decoding condition is satisfied, up to the unit time during the transmission period The process of performing decoding on the received signal, and if the decoding is successful, setting the wireless signal processor to the low power mode for the remaining time period of the transmission period, and the unit time being the last unit time of the transmission period In this case, it includes a process of performing decoding on the signal received through the radio signal processor up to the last unit time of the transmission period regardless of the decoding condition.

The method according to an embodiment of the present invention; In the method of reducing power consumption through early decoding, the process of performing decoding on a signal received up to a predetermined early decoding point in one transmission period, and when the decoding fails, received until a next unit time in the transmission period A process of performing decoding on a signal, and if the decoding is successful, a process of checking whether the number of successive decoding successes including the success of decoding of the transmission period exceeds a predetermined threshold, and the number of successive decoding successes is the threshold value If exceeds, the process of reducing the early decoding time by one unit time.

The method according to an embodiment of the present invention; In the method of reducing power consumption through early decoding, at the start of one transmission period, the transmission period according to at least one of a power consumption gain obtained through early decoding and a reception quality during a predetermined time period before the transmission period. A process of determining whether to perform early decoding at, and when it is determined that the early decoding is to be performed, a process of performing decoding on a signal received up to an early decoding point in the transmission period, and the decoding If successful, the process of setting the wireless signal processing unit to the low power mode for the remainder of the transmission period.

An apparatus according to an embodiment of the present invention includes; An apparatus for reducing power consumption through early decoding, comprising: a wireless signal processing unit for receiving a radio signal; a baseband signal processing unit for processing an output signal of the wireless signal processing unit; and a decoder for decoding an output signal of the baseband signal processing unit; , Determines whether a predetermined decoding condition is satisfied in a unit time for decoding during one transmission period, and when the decoding condition is satisfied, the decoder performs decoding on a signal received up to the unit time during the transmission period. Control, and if the decoding is successful, the wireless signal processing unit is set to a low power mode for the remaining time period of the transmission period, and when the unit time is the last unit time of the transmission period, the transmission regardless of the decoding condition And a control unit for controlling the decoder to perform decoding on the signal received through the radio signal processing unit until the last unit time of the period.

An apparatus according to an embodiment of the present invention includes; An apparatus for reducing power consumption through early decoding, comprising: a wireless signal processing unit for receiving a radio signal; a baseband signal processing unit for processing an output signal of the wireless signal processing unit; and a decoder for decoding an output signal of the baseband signal processing unit; , Control the decoder to perform decoding on the signal received up to an early decoding point in one transmission period, and when the decoding fails, decode the signal received up to the next unit time in the transmission period, When the decoding is successful, it is checked whether the number of successive decoding successes including the success of decoding of the transmission period exceeds a predetermined threshold, and when the number of successive decoding successes exceeds the threshold, the early decoding time is determined by one It includes a control unit that decreases by a unit time of.

An apparatus according to an embodiment of the present invention includes; An apparatus for reducing power consumption through early decoding, comprising: a wireless signal processing unit for receiving a radio signal; a baseband signal processing unit for processing an output signal of the wireless signal processing unit; and a decoder for decoding an output signal of the baseband signal processing unit; , At the start of one transmission period, it is determined whether to perform early decoding in the transmission period according to at least one of a power consumption gain obtained through early decoding and a reception quality during a predetermined time period before the transmission period, , When it is determined that the early decoding is to be performed, the decoder is controlled to perform decoding on a signal received up to a predetermined early decoding point in the transmission period, and when the decoding is successful, the remaining time of the transmission period And a control unit for setting the wireless signal processing unit to a low power mode.

Other aspects, features and benefits as described above of certain preferred embodiments of the present invention will become more apparent from the following description, which is handled in conjunction with the accompanying drawings.
1 illustrates a frame structure of a wireless communication system to which the present invention can be applied.
2 is a block diagram illustrating a structure of a receiver including a decoder in a wireless communication system.
3 shows a timing diagram for explaining a decoding operation in a general decoding mode.
4 is a block diagram illustrating a structure of a receiver supporting early decoding according to an embodiment of the present invention.
5 is a timing diagram illustrating a decoding operation in an early decoding mode according to an embodiment of the present invention.
6A and 6B are graphs showing an effective coding rate according to a location of a reception slot for each transport channel.
7 is a diagram for explaining a criterion for setting a threshold value of a link quality index for evaluating channel quality for each slot.
8 is a flowchart illustrating an operation of determining early decoding according to an embodiment of the present invention.
9 is a timing diagram illustrating an operation of determining an early decoding time point according to an embodiment of the present invention.
10 is a flowchart illustrating an operation of determining an early decoding time point according to an embodiment of the present invention.
11 is a timing diagram illustrating a predetermined early decoding time point according to an embodiment of the present invention.
12 is a timing diagram illustrating a decoding operation of a plurality of transport channels according to an embodiment of the present invention.
13 is a graph showing a comparison of reception quality according to a channel environment in a normal decoding mode and an early decoding mode.
14 is a flowchart illustrating an operation of activating an early decoding mode according to an embodiment of the present invention.
It should be noted that throughout the drawings, like reference numbers are used to show the same or similar elements, features, and structures.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In describing the embodiments, descriptions of technical contents that are well known in the technical field to which the present invention pertains and are not directly related to the present invention will be omitted. This is to more clearly convey the gist of the present invention by omitting unnecessary description.

For the same reason, some components in the accompanying drawings are exaggerated, omitted, or schematically illustrated. In addition, the size of each component does not fully reflect the actual size. The same reference numerals are assigned to the same or corresponding components in each drawing.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in a variety of different forms, only the present embodiments are intended to complete the disclosure of the present invention, and the general knowledge in the technical field to which the present invention pertains. It is provided to completely inform the scope of the invention to those who have it, and the invention is only defined by the scope of the claims. The same reference numerals refer to the same components throughout the specification.

In this case, it will be appreciated that each block of the flowchart diagrams and combinations of the flowchart diagrams may be executed by computer program instructions. Since these computer program instructions can be mounted on the processor of a general purpose computer, special purpose computer or other programmable data processing equipment, the instructions executed by the processor of the computer or other programmable data processing equipment are described in the flowchart block(s). It creates a means to perform functions. These computer program instructions can also be stored in computer-usable or computer-readable memory that can be directed to a computer or other programmable data processing equipment to implement a function in a particular way, so that the computer-usable or computer-readable memory It is also possible to produce an article of manufacture containing instruction means for performing the functions described in the flowchart block(s). Computer program instructions can also be mounted on a computer or other programmable data processing equipment, so that a series of operating steps are performed on a computer or other programmable data processing equipment to create a computer-executable process to create a computer or other programmable data processing equipment. It is also possible for instructions to perform processing equipment to provide steps for executing the functions described in the flowchart block(s).

In addition, each block may represent a module, segment, or part of code that contains one or more executable instructions for executing the specified logical function(s). In addition, it should be noted that in some alternative execution examples, functions mentioned in blocks may occur out of order. For example, two blocks shown in succession may in fact be executed substantially simultaneously, or the blocks may sometimes be executed in reverse order depending on the corresponding function.

In this case, the term'~ unit' used in this embodiment refers to software or hardware components such as field-programmable gate array (FPGA) or application specific integrated circuit (ASIC), and'~ unit' is a certain role. Perform them. However,'~ part' is not limited to software or hardware. The'~ unit' may be configured to be in an addressable storage medium, or may be configured to reproduce one or more processors. Thus, as an example,'~ unit' refers to components such as software components, object-oriented software components, class components and task components, processes, functions, properties, and procedures. , Subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, database, data structures, tables, arrays, and variables. The components and functions provided in the'~ units' may be combined into a smaller number of elements and'~ units', or may be further divided into additional elements and'~ units'. In addition, components and'~ units' may be implemented to play one or more CPUs in a device or a security multimedia card.

In describing the embodiments of the present specification in detail, the OFDM-based wireless communication system will be the main target, but the main subject of the present specification is the scope of the present specification to other communication systems and services having a similar technical background and channel type. It can be applied within the range not significantly departing from, this will be possible by the judgment of a person skilled in the technical field of the present specification.

In embodiments to be described later, the digital error correction decoder (hereinafter referred to as the decoder) of the wireless terminal may attempt to decode every predetermined unit time before receiving all signals corresponding to one transmission period. By controlling the circuit part, it is possible to reduce the power consumption of the wireless terminal.

1 illustrates a frame structure of a wireless communication system to which the present invention can be applied.

Referring to FIG. 1, wireless communication between a transmitter and a receiver is performed through a transport channel. In the downlink, the transmitter may be a base station and the receiver may be a wireless terminal. In the uplink, the opposite is true. The transmission period (TTI) of the transmission channel is composed of one or a plurality of frames (Frame) (102). One frame 102 is composed of a plurality of sub-frames 104, each sub-frame 104 includes a plurality of slots (106).

In 3rd Generation Partnership Project (3GPP) Long-Term Evolution (LTE), which is one of the standards of wireless communication, one frame is 10 ms long, and one frame is divided into 10 subframes each 1 ms long, and each subframe Is divided into two slots that are 0.5ms long. One subframe is a minimum unit of a transmission period (TTI), and a transmission period may be allocated from a minimum of 1 ms to a maximum of 40 ms for each transport channel (TrCH).

Output bits after encoding are uniformly spread over a plurality of frames corresponding to one transmission period through a channel interleaver. The decoder performs decoding every predetermined unit time after receiving a signal of one transmission period through a baseband signal processor (including a demodulator as an example). The unit time may be, for example, a half slot, one slot, or a plurality of slots.

2 is a block diagram illustrating a structure of a receiver including a decoder in a wireless communication system.

2, a radio frequency (RF) signal processing unit (RF processor) 210 receives a radio signal through a receiving antenna unit, converts it into a baseband signal, and then converts it into a baseband signal. BB processor) 220. The baseband signal processing unit 220 processes and outputs the baseband signal according to a signal processing algorithm. The decoder 230 performs channel decoding on the signal output from the baseband signal processing unit 220 to correct an error, and then recovers and outputs information bits transmitted by the transmitter.

The decoder 230 generally performs decoding after receiving all of the plurality of frames corresponding to one transmission period through the baseband signal processing unit 220 (including a demodulator as an example). In this specification, this is referred to as a normal decoding mode.

3 shows a timing diagram for explaining a decoding operation in a general decoding mode.

Referring to FIG. 3, one transmission period 300 includes N slots, and the baseband signal processing unit 320 or a channel measuring unit (not shown) for each slot is the channel quality (as an example, Link quality or signal quality), for example, a Signal to Interference Ratio (SIR) may be measured and output. The decoder 230 in the normal decoding mode attempts to decode the entire received signal of the corresponding transmission period at the time 310 when the signal of the last slot is completely received, that is, at the boundary of one transmission period. It is irrelevant to the channel quality of each slot.

When the decoder 230 operates in the general decoding mode, the RF signal processing unit 210 ensures good signal quality (for example, a low block error rate (BLER)), in a high or normal signal quality mode ( Hereinafter referred to as general signal quality mode). As an example, the general signal quality mode may operate to generate a signal having an Error Vector Magnitude (EVM) higher than a predetermined threshold.

4 is a block diagram illustrating a structure of a receiver supporting early decoding according to an embodiment of the present invention.

Referring to FIG. 4, the RF signal processing unit 410 receives a radio signal through a receiving antenna unit, converts it into a baseband signal, and transmits it to the baseband signal processing unit 420. The baseband signal processing unit 420 processes and outputs the baseband signal according to a signal processing algorithm. The decoder 430 performs channel decoding on the signal output from the baseband signal processing unit 420 to correct an error, and then recovers and outputs information bits transmitted by the transmitter.

The decoder 430 supporting early decoding may attempt decoding in units of slots before receiving all signals of one transmission period. In this specification, this is referred to as an early decoding mode.

The decoder 430 attempts to decode a signal received from an early decoding point before the end of one transmission period to the early decoding point in a corresponding transmission period. During decoding, signals of slots that have not yet been received among the slots constituting one transmission period are filled with'erasure(=0)', and signals of already received slots and signals filled with the erasure are subject to decoding. If the effective coding rate is low and the channel conditions are good, the signal quality of each unit section constituting one transmission period is relatively high, so that only some section signals constituting one transmission period and the remaining section signals filled with erasure are used. There is a high probability of successful decoding. Upon successful decoding, the RF signal processing unit 410 may reduce power consumption by not performing an unnecessary reception operation during a period corresponding to slots that have not yet been received in a corresponding transmission period.

For example, AMR (Adaptive Multi-Rate) 12.2kbps, one of the transmission modes of 3GPP, uses a relatively low channel coding rate during the transmission period. In an environment with good channel conditions, even if only some slots in the transmission period are used There is a high probability that the transport channel will be successfully received. The general decoding mode attempts to decode after receiving all the signals of one transmission period even in such a good channel situation, so that the RF signal processing unit 410 operates in the normal signal quality mode during all periods of one transmission period, thereby making a voice call. It may cause unnecessary current consumption. Maintaining a high signal quality mode of the RF signal processing unit 410 in a transmission channel having a low transmission rate unnecessarily increases the power consumption of the entire terminal.

The controller 440 may determine whether the decoder 430 operates in a normal decoding mode or an early decoding mode for at least one transmission period. When it is determined as the early decoding mode, the control unit 440 is an operation mode in which the RF signal processing unit 410 and/or the baseband signal processing unit 420 consumes less power according to the decoding result transmitted from the decoder 440. For example, the RF signal processing unit 410 and/or the baseband signal processing unit 420 may be controlled to operate in a low signal quality mode. As an example, the low signal quality mode of the RF signal processing unit 410 may allow a signal having an EVM that is not higher than a predetermined threshold. The RF signal processing unit 410 may maintain the low signal quality mode during the period corresponding to the remaining slots of the corresponding transmission period, and may return to the normal signal quality in the next transmission period.

The RF signal processing unit 410 is set to a general signal quality mode when starting to receive a transmission channel and outputs a signal of high signal quality. When operating in the early decoding mode, the decoder 430 performs decoding of data transmitted from the baseband signal processing unit 420 at a time point indicated by the control unit 440, a predetermined early decoding time point, or every slot. Attempts are made, and the decoding result is reported to the control unit 440. When a plurality of transport channels are set in the receiver, the decoder 430 individually decodes signals of the plurality of transport channels in each slot, and transmits the decoding results for the plurality of transport channels to the controller 440. I can deliver. When the decoding success is notified from the decoder 430 in a slot other than the end of one transmission period, the control unit 440 provides the RF signal processing unit 410 in a low signal quality mode (ie, low power consumption) during the remaining slot(s) of the transmission period. Mode).

As an embodiment, the controller 440 may determine a time point at which the decoder 440 attempts early decoding, that is, an early decoding time point. The baseband signal processing unit 420 performs channel estimation, frequency/time synchronization, and channel compensation on signal samples of the baseband signal transmitted from the RF signal processing unit 410, and the signal The channel quality of the samples is estimated and reported to the control unit 440. The channel quality may be, for example, a Signal to Interference Ratio (SIR) for signal samples in each slot. The control unit 440 may use the SIR for each slot as a link quality indicator for a corresponding slot to determine whether the decoder 430 attempts early decoding in the corresponding slot. The early decoding time may be determined in units of slots or in units of periods including a predetermined number of slots.

As an embodiment, the control unit 440 stores the time when CRC good is reported as a decoding result from the decoder 440 in one transmission period as an early decoding time in the next transmission period, and information on the early decoding time in the next transmission period. May be provided to the decoder 440. The decoder 440 decodes signals received up to the early decoding point indicated by the control unit 440 within one transmission period.

5 is a timing diagram illustrating a decoding operation in an early decoding mode according to an embodiment of the present invention.

5, in the current transmission period 500, the baseband signal processing unit 420 measures the SIR representing the channel quality in slot units using a pilot channel or a reference channel transmitted from the base station and reports it to the control unit 440. do. In the illustrated example, Slot SIR(k) may be the channel quality of slot k, or the channel quality of signals during slots 0 to k. The control unit 440 derives a link quality metric (LQM) TTI_LQM(k) based on the slot SIR(k) reported by the baseband signal processing unit 420. The TTI_LQM(k) of slot k is compared with a predetermined threshold TTI_LQM_TH, and the control unit 440 determines whether to attempt decoding of the signal received up to slot k according to the comparison result. Here, the threshold value may be obtained from a look-up table having different values for each slot to attempt decoding, or may be implemented as a single constant value for the slots to be decoded. The control unit 440 may calculate the link quality indicator TTI_LQM based on the slot SIR according to a predetermined algorithm, and as an example, a technique widely known in the art may be used.

When TTI_LQM(k) of slot k is smaller than TTI_LQM_TH (510), the control unit 440 controls the decoder 430 to not attempt decoding in slot k. When TTI_LQM(k+1) of slot k+1 is greater than or equal to TTI_LQM_TH (520), the controller 440 controls the decoder 430 to attempt decoding in slot k+1. In this case, the early decoding time is slot k+1.

The decoder 430 decodes transport channels in a slot indicated by the control unit 440 within a transmission period of a plurality of set transport channels, and reports a result of the decoding to the control unit 440. The decoding result refers to a result of a CRC (Cyclic Redundancy Code) check for information bits obtained as a result of decoding, and may be CRC good when decoding is successful and CRC bad when decoding fails.

When decoding results for a plurality of transport channels set in the terminal are different from each other, that is, when both CRC good and CRC bad for transport channels occur in a specific slot, the control unit 440 is used to control the transport channels in which CRC failure occurs. It is possible to control the decoder 430 to attempt decoding only in the next slot, or attempt to decode all transport channels in the next slot. Accordingly, even if the signal quality mode of the RF signal processing unit 410 is kept low for a predetermined period, the reception quality (ie, BLER) of transmission channels to be received may be guaranteed not to have a performance degradation compared to the general decoding mode.

As another embodiment, the control unit 440 may determine a plurality of conditions for performing decoding for each slot before the transmission period for each transport channel is terminated, or for each predetermined number of slots. The plurality of conditions may include a condition for an effective coding rate of a corresponding transport channel. As an example, the above condition is satisfied when the effective coding rate of the transport channel is less than 1. The plurality of conditions may include a condition for the link quality indicator (LQM) described above. The channel quality of each slot may be TTI_LQM obtained using a pilot channel or a reference channel of a corresponding slot, and TTI_LQM may be calculated as an effective SIR or Mean Mutual Information per coded Bit (MMIB). The above condition is satisfied when TTI_LQM is greater than or equal to a threshold corresponding to the target BLER (target BLER) of the corresponding transport channel. The plurality of conditions may include a condition for the number of remaining slots. As an example, the condition is the length of the section in which the RF signal processing unit 410 can be maintained in a low signal quality mode, that is, the number of slots from the next slot of the successful decoding slot to the last slot of the current transmission section is a predetermined minimum It is satisfied when it is greater than the number (=X, for example 1).

6A and 6B are graphs showing an effective coding rate according to a location of a reception slot for each transport channel. Since the effective coding rate 610 for the transport channel TrCH0 shown in FIG. 6A becomes less than the threshold (=1) from the 10th slot, the control unit 440 for TrCH0 is the condition of the effective coding rate in the 10th and subsequent slots. We judge that we are satisfied. Since the effective coding rate 620 for the transport channel TrCH3 shown in FIG. 6B is less than the threshold (=1) from the 22nd slot among all 60 slots, the control unit 440 for TrCH3 It is determined that the conditions of the effective coding rate are satisfied in the fields.

7 is a diagram for explaining a criterion for setting a threshold value of a link quality index for evaluating channel quality for each slot. As shown, the control unit 440 sets a threshold TTI_LQM_TH 710 corresponding to the target BLER 705 required for each of the transport channels set in the receiver. The BLER according to TTI_LQM can be obtained experimentally/empirically or in a predetermined table.

8 is a flowchart illustrating an operation of determining early decoding according to an embodiment of the present invention. The illustrated operation may be executed in every transmission cycle by a wireless terminal having a receiver configured as shown in FIG. 4 as an example.

Referring to FIG. 8, in step 805, the control unit 440 sets the RF signal processing unit 410 to a general signal quality mode. The RF signal processing unit 410 receives each slot of one transmission period according to the general signal quality mode. The general signal quality mode may have a higher EVM than the low signal quality mode described later, and may require relatively large power consumption.

In step 810, the control unit 440 determines whether all conditions for determining early decoding in the current slot are satisfied or, if necessary, some conditions are satisfied for each slot of the transmission period. As an embodiment, the control unit 440 determines whether the effective coding rate of the transport channel in the current slot is less than a predetermined threshold (for example, 1), the link quality index calculated in the current slot is greater than or equal to the threshold (TTI_LQM_TH), and the current transmission period. It may be determined whether the number of remaining slots of is greater than the threshold value X.

If all of the above conditions are satisfied, in step 815, the controller 440 instructs the decoder 430 to perform decoding on signals received up to the current slot during the current transmission period. As another embodiment, the controller 440 may determine to perform decoding in the current slot when at least one specified condition among the above conditions, for example, an effective coding rate condition, is satisfied.

In step 820, the controller 440 determines whether decoding has succeeded in the signal received up to the current slot according to the decoding result received from the decoder 430. If the decoding success is reported, in step 825, the control unit 440 performs an RF signal so that the RF signal processing unit 410 operates in a low power mode, that is, a low signal quality mode during a time period corresponding to the remaining slot(s) of the current transmission period. Controls the processing unit 410. When a plurality of transport channels are configured in the receiver, the decoding result may indicate whether decoding is successful for the plurality of transport channels. Then, the control unit 440 may adjust the RF signal processing unit 410 to the low power mode when decoding of all transmission channels or a predetermined number or more of transmission channels is successful. As another embodiment, the controller 440 may stop, that is, disable the RF signal processor 410, instead of adjusting the RF signal processor 410 to a low power mode for the remaining slots of the current transmission period. As a selectable embodiment, when decoding success is detected before the end of the current transmission period, the control unit 440 stops the call originating operation for the remainder of the current transmission period, or stops both the reception and transmission operations of the call. I can.

In step 840, when the currently received slot is the last slot of the current transmission period, the controller 440 ends the operation. If it is not the last slot, the controller 440 receives the next slot in step 845 and then proceeds to step 810 to determine whether the decoding condition of the next slot is satisfied.

If it is determined in step 810 that the current slot does not satisfy the early decoding condition, in step 830 the controller 440 determines whether the currently received slot is the last slot of the current transmission period. If the last slot is received, the controller 440 proceeds to step 815 and controls the decoder 430 to decode signals up to the last slot regardless of whether the early decoding condition is satisfied. If the current slot does not satisfy the early decoding condition and is not the last slot, in step 835, the control unit 440 maintains the RF signal processing unit in the normal signal quality mode, and after receiving the next slot, to determine the early decoding of the next slot. Proceed to step 810.

9 is a timing diagram illustrating an operation of determining an early decoding time point according to an embodiment of the present invention.

Referring to FIG. 9, reference numeral 900 denotes decoding timing of a transport channel having TTI0, and reference numeral 920 denotes decoding timing of a transport channel having TTI1. Here, TTI0 is 1/2 of TTI1. The decoder may attempt decoding every predetermined unit time within one transmission period 900 and 920. The unit time is TTI0/N, where N is a positive integer. As an example, the minimum value of TTI0/N may be one slot.

In the case of the transport channel 900 having TTI0, the decoder can decode up to N times within one transmission period, and in the case of the transport channel 900 having TTI1, the decoder decodes up to 2N times within one transmission period. Can be done. The minimum decoding time at which the decoder can operate is TTI0/N, the last time of one transmission period becomes the decoding time (910,930) of the normal decoding mode, and the unit times before the end of one transmission period becomes the early decoding time (905,925). I can.

Early decoding in the first TTI starts at the time point TTI0/N.

10 is a flowchart illustrating an operation of determining an early decoding time point according to an embodiment of the present invention. The illustrated operation may be executed in every transmission cycle by a wireless terminal having a receiver configured as shown in FIG. 4 as an example.

Referring to FIG. 10, in step 1005, the controller 440 instructs the decoder 430 to attempt decoding at a previously stored decoding point in the current transmission period. The decoding time in the first transmission period may be a unit time for decoding (for example, a first slot). In the transmission period after the first, the decoding time becomes the value stored in the previous transmission period.

In step 1010, the controller 440 determines whether decoding is successful for the signal received up to the indicated decoding time according to the decoding result received from the decoder 430, and if the decoding fails, proceeds to step 1015 and proceeds to the decoder 430. ) Is the next unit time, as an example, attempts to decode after receiving the signal of the next slot. On the other hand, if decoding is successful, the control unit 440 proceeds to step 1020. When a plurality of transport channels are configured in the receiver, the controller 440 may proceed to step 1020 when decoding of all transport channels is successful or when decoding of a predetermined number or more of transport channels is successful.

In step 1020, the control unit 440 measures the number of successive decoding successes (referred to as successive decoding success counts) in previous transmission periods including the current transmission period, and in step 1025, a threshold at which the number of successive decoding successes is predetermined ( Determine whether it exceeds D). The number of successive decoding successes is measured in units of a transmission period. As an example, when decoding is successively succeeded during three transmission periods before the current transmission period, the number of successive decoding successes is 4. The threshold may be changed according to a channel environment, for example, a Doppler frequency. When the threshold is set to 1, the decoding time can be updated every transmission period.

When the number of successive decoding successes exceeds the threshold (D), in step 1030, the control unit 440 moves the stored decoding time by a unit time (TTI0/N), as an example, one slot before the stored decoding time. To change. As an example, when the stored decoding time point is slot k, in step 1030, the controller 440 advances the decoding time point to slot (k-1) and stores it. On the other hand, when the number of successive decoding successes does not exceed the threshold (D), information on a time point at which decoding is successful in the current transmission period is stored as a decoding time point in step 1035. The stored decoding time may be used in the next transmission period.

When a plurality of transport channels are configured in the receiver, the operation shown in FIG. 10 may be individually performed for each transport channel. When the coding rate of the specific transport channel is changed, the controller 440 may initialize the decoding time of the transport channel.

The embodiment shown in FIG. 10 may be combined with the embodiment of FIG. 8. As an example, the control unit 440 determines whether the early decoding condition is satisfied for each slot from the first slot of a transmission period, but instead determines the early decoding condition for each slot or every predetermined unit time from the decoding time determined as shown in FIG. Can be checked.

In an embodiment to be described later, a decoding time to perform early decoding within one transmission period may be determined according to a power consumption gain obtainable through early decoding. As an embodiment, the decoding time is an index measured by the terminal, for example, a signal-to-interference ratio (SIR) or a symbol signal-to-noise ratio (SNR) of a transport channel, a symbol SNR of a pilot channel, and a block of a transport channel. It may be determined according to at least one of the error rates (BLER).

11 is a timing diagram illustrating a predetermined early decoding time point according to an embodiment of the present invention.

Referring to FIG. 11, reference numeral 1100 shows the decoding timing of a transport channel with TTI0=20ms. In the normal decoding mode, the decoder attempts to decode at the end of one transmission period (1110), and in the early decoding mode, the decoder Tries to decode at a predetermined early decoding time 1105 before the end of one transmission period. Reference number 1120 shows the decoding timing of the transport channel with TTI1 = 40ms.In the normal decoding mode, the decoder attempts to decode at the end point 1130 of one transmission period, and in the early decoding mode, the decoder ends one transmission period. Decoding is attempted at a previously determined early decoding time 1125.

For example, the predetermined early decoding time 1105 may be a time when all the outputs of the baseband signal processor for the first 10 ms (that is, one frame) are transmitted to the decoder. The early decoding time may be varied by the control unit. If the decoding of the signal of one frame is successful, assuming that the delay time passing through the baseband signal processing unit is insignificant, the control unit can transition the operation mode of the RF signal processing unit to the low signal quality mode for approximately 10 ms for the next frame. have. The operation mode of the RF signal processing unit can be adjusted to the normal mode according to the start point of the next transmission period.

When early decoding in the early decoding mode is performed for a plurality of transmission channels having the same transmission period, the control unit performs a decoding failure (ie, CRC failure) in a predetermined number of transmission channel(s), and the RF signal processing unit performs a general signal quality. There is adjustment in mode. In this case, at the decoding time of the normal decoding mode, that is, at the end of one transmission period, the decoder may perform decoding on transport channels that have failed to decode at the previous decoding time or for all transport channels at which the transmission period ends. .

12 is a timing diagram illustrating a decoding operation of a plurality of transport channels according to an embodiment of the present invention.

Referring to FIG. 12, at least one transmission channel TrCH0 1220 having a transmission period of 10 ms and at least one transmission channel TrCH1 1225 having a transmission period of 20 ms are set in the receiver, and the RF signal processing unit 1205 Operates with a minimum transmission period of 10ms.

Reference numeral 1230 denotes a decoding time according to a general decoding mode or a decoding time when an early decoding fails in the early decoding mode. Reference numeral 1235 denotes a decoding time point of the TrCH0 1220 in the early decoding mode, and reference numeral 1240 denotes a decoding time point of the TrCH1 1225 in the early decoding mode.

At the start of the transmission period, the operation mode 1210 of the RF signal processing unit is set to a general signal quality mode, that is, a high EVM. If decoding of the symbols of TrCH0 is successful at decoding time 1245, the operation mode 1210 of the RF signal processor is adjusted to a low signal quality mode, that is, a low EVM. The low signal quality mode is maintained until the corresponding transmission period ends, and when the next transmission period starts, the RF signal processing unit is initialized to the general signal quality mode. Since decoding of TrCH0 is successful at decoding time 1545, the decoder does not need to perform decoding on TrCH0 at decoding time 1250.

At decoding time 1250, the decoder performs decoding on symbols of TrCH0 and TrCH1, respectively. When the decoding of TrCH0 fails and the decoding of TrCH1 is successful, the operation mode 1210 of the RF signal processing unit is maintained in a high signal quality mode. Since decoding of TrCH0 has failed, at decoding time 1260, the decoder tries again to decode the entire signal of TrCH0 received in the corresponding transmission period.

13 is a graph showing a comparison of reception quality according to a channel environment in a normal decoding mode and an early decoding mode. Here, the channel environment is indicated by symbol SNR, and the reception quality is indicated by BLER.

Referring to FIG. 13, when decoding is attempted at the end of one transmission period (i.e., normal decoding mode) at the same symbol SNR, BLER0 (1310) is BLER1 (i.e., an early decoding mode) at the intermediate time. 1305). Therefore, the reception quality of the general decoding mode is deteriorated compared to the earlier decoding mode. Therefore, the control unit can determine whether to activate the early decoding mode of the decoder according to various criteria.

As an example, when the reception quality of transport channels within a predetermined window satisfies a predetermined criterion, an early decoding mode of the decoder may be activated. As an example of another criterion, it may be determined whether to continue the early decoding mode based on the block error rate of the early decoding mode acquired by activating the early decoding mode unconditionally for a certain period of time and the power consumption gain calculated in advance. As an example, the power consumption gain may be calculated through a power consumption gain through an operation mode adjustment of an RF signal processor and an increase in power consumption according to an increase in the number of decoding times of a decoder. As an example of another criterion, when the occurrence of a burst error is detected, the early decoding mode may not be performed until the burst error is released.

14 is a flowchart illustrating an operation of activating an early decoding mode according to an embodiment of the present invention. The illustrated operation is performed by a wireless terminal having a receiver configured as shown in FIG. 4, as an example, at each transmission period of each transmission channel or at a predetermined operation period including at least one transmission period, or according to a predetermined trigger condition. It can be run periodically.

Referring to FIG. 14, in step 1405, the control unit 440 sets the RF signal processing unit 410 to a normal signal quality mode, and sets the decoder 430 to a normal decoding mode. In step 1410, the control unit 440 determines whether to activate the early decoding mode according to the characteristics of each transport channel and a power consumption gain obtained through early decoding. If the early decoding mode cannot be activated or the gain obtainable through early decoding is small or insignificant, in step 1440, the controller 440 maintains the decoder 430 in the normal decoding mode.

As an embodiment, the controller 440 may determine to activate the early decoding mode when the reception quality of transport channels within a previous predetermined window satisfies a predetermined criterion. In another embodiment, the control unit 440 includes channel quality indicators transmitted from the baseband signal processing unit 420, for example, the SNR of the data channel or the pilot channel, the SIR of the pilot channel, the Doppler estimate, and the Channel Delay Profile. : CDP) It is possible to predict the reception quality of a transport channel, that is, a block error rate during early decoding, and determine whether to activate the early decoding mode according to the block error rate. As an example, when the block error rate of the early decoding mode acquired during a predetermined time period does not exceed a predetermined reference value, it may be determined to activate the early decoding mode. As another embodiment, the control unit 440 calculates the power consumption gain through the sum of the power consumption gain according to the low signal quality mode of the RF signal processing unit 410 and the power consumption increase according to the early decoding mode of the decoder 430. When the power consumption gain exceeds a predetermined reference value, it may be determined to activate the early decoding mode.

The block error rate in the early decoding mode is actually estimated for a transmission channel or a pilot channel based on information indicating the relationship between the symbol SNR measured for the transmission channel and the BLER in the early decoding mode (for example, a graph or table). It can be calculated from the symbol SNR. Techniques for mapping the effective SNR and BLER are well known in the art.

As another embodiment, when the occurrence of a burst error in the wireless channel is detected, the controller 440 activates the early decoding mode, and may determine to maintain the early decoding mode until the burst error is released. As another embodiment, the controller 440 may activate the early decoding mode according to information indicated through the upper layer.

When it is determined to activate the early decoding mode, in step 1415, the controller 440 operates the decoder 430 in the early decoding mode. In step 1420, the decoder 440 performs decoding at a predetermined early decoding time within each transmission period of the transport channels configured in the receiver or at an early decoding time indicated by the control unit 440, and controls the decoding result for each transport channel. Forward to 440.

In step 1425, the control unit 440 determines whether the reception quality of the transmission channels attempted to decode satisfies a predetermined condition. As an example, the controller 440 may determine that the reception quality is good when decoding success is notified for all transport channels or a predetermined number (T) or more of transport channels, and proceed to step 1430. In step 1430, the control unit 1430 adjusts the RF signal processing unit 410 to the low signal quality mode during a period corresponding to the remaining slots of the current transmission period. In the next transmission period of the corresponding transmission channels, the RF signal processing unit 410 may return to the normal signal quality mode.

On the other hand, when decoding fails in at least one transport channel or the number of successfully decoded transport channels is less than a predetermined number (T), the control unit 440 maintains the RF signal processing unit 410 in the general signal quality mode in step 1435. . As an embodiment, in step 1435, the control unit 440 may adjust the RF signal processing unit 410 to a high signal quality mode. As an example, the high signal quality mode may include an EVM higher than that of the general signal quality mode.

In the general decoding mode, the decoder attempts to decode according to the end point of the transmission period of each transport channel, and may attempt decoding at a point before the end of the transmission period of each transport channel in the early decoding mode. That is, the decoder may attempt to decode all transport channels in every slot, or may attempt to decode some transport channels.

The embodiment shown in FIG. 14 may be combined with at least one of the embodiments of FIGS. 8 and 10. As an example, the controller 440 may determine whether to activate the early decoding mode at a predetermined period, and when it is determined to activate the early decoding mode, perform early decoding as in the embodiment of FIG. 8 or 10.

Various embodiments of the present invention may be implemented as computer readable code in a computer readable recording medium from a specific viewpoint. A computer-readable recording medium is any data storage device capable of storing data that can be read by a computer system. Examples of computer-readable recording media include read only memory (ROM: ROM), random access memory (RAM:'RAM), and compact disk-read only memory. : CD-ROMs), magnetic tapes, floppy disks, optical data storage devices, and carrier waves (data transmission over the Internet, etc.) can do. The computer readable recording medium can also be distributed through networked computer systems, so that the computer readable code is stored and executed in a distributed manner. In addition, functional programs, codes, and code segments for achieving various embodiments of the present invention can be easily interpreted by experienced programmers in the field to which the present invention is applied.

In addition, it will be appreciated that the apparatus and method according to various embodiments of the present invention can be realized in the form of hardware, software, or a combination of hardware and software. Such software may be, for example, a volatile or nonvolatile storage device such as a storage device such as a ROM, or a memory such as a RAM, memory chip, device or integrated circuit, or For example, it may be optically or magnetically recordable, such as a compact disk (CD), a DVD, a magnetic disk, or a magnetic tape, and stored in a storage medium that can be read by a machine (for example, a computer). The method according to various embodiments of the present invention may be implemented by a computer or mobile terminal including a control unit and a memory, and such a memory is used to store a program or programs including instructions for implementing the embodiments of the present invention. You will find that it is an example of a suitable machine-readable storage medium.

Accordingly, the present invention includes a program including a code for implementing the apparatus or method described in the claims of the present specification, and a storage medium readable by a machine (such as a computer) storing such a program. In addition, such a program may be electronically transferred through any medium such as a communication signal transmitted through a wired or wireless connection, and the present invention suitably includes equivalents thereto.

In addition, the device according to various embodiments of the present disclosure may receive and store a program from a program providing device connected by wire or wirelessly. The program providing device includes a program including instructions for the program processing device to perform a preset content protection method, a memory for storing information necessary for the content protection method, and for performing wired or wireless communication with the graphic processing device. It may include a communication unit and a control unit that automatically transmits a request from the graphic processing device or a corresponding program to the transmission/reception device.

The embodiments of the present invention disclosed in the present specification and drawings are merely provided for specific examples to easily explain the technical content of the present invention and to aid understanding of the present invention, and are not intended to limit the scope of the present invention. In addition, the embodiments according to the present invention described above are merely exemplary, and those of ordinary skill in the art will understand that various modifications and equivalent ranges of embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention should be determined by the following claims.

Claims (19)

In the method of reducing power consumption through early decoding,
At the start of a transmission period, a process of determining whether to perform the early decoding in the transmission period according to a first power consumption gain obtainable through the early decoding; and
A process of determining whether a decoding condition predetermined in a unit time for decoding during the transmission period is satisfied, and
When the decoding condition is satisfied, the process of performing decoding on the signal received up to the unit time during the transmission period,
When the decoding is successful, the process of setting the wireless signal processing unit to a low power mode for the remaining time period of the transmission period,
When the unit time is the last unit time of the transmission period, the process of performing decoding on the signal received through the wireless signal processing unit up to the last unit time of the transmission period regardless of the decoding condition,
The process of determining whether to perform the early decoding in the transmission period,
The first power consumption gain is calculated through the sum of the second power consumption gain resulting from operating the wireless signal processor in the low power mode and the power consumption increase resulting from operating the decoder in the early decoding mode, and the first power consumption gain And determining to perform the early decoding in the transmission period when the reference value is exceeded. The method of claim 1, wherein the decoding condition is
A first condition satisfied when the effective coding rate of the signal received up to the unit time is less than a first threshold;
A second condition that is satisfied when the link quality index calculated in the unit time is greater than or equal to a second threshold;
And at least one of a third condition satisfied when the number of unit times after the unit time in the transmission period is greater than a third threshold. The method of claim 1, wherein determining whether the decoding condition is satisfied,
And starting the determination of the decoding condition at a time determined according to a decoding result of a previous transmission period among the transmission periods. The method of claim 1, wherein the low power mode,
And at least one of a low error vector size (EVM) for the wireless signal processing unit, stopping a call originating operation, and stopping a call reception and origination operation. delete In the method of reducing power consumption through early decoding,
At the start of a transmission period, a process of determining whether to perform the early decoding in the transmission period according to a first power consumption gain obtainable through the early decoding; and
A process of performing decoding on a signal received up to an early decoding point in the transmission period, and
When the decoding fails, the process of performing decoding on the signal received until the next unit time within the transmission period,
When the decoding is successful, the process of setting the wireless signal processing unit to a low power mode for the remaining time period of the transmission period,
When the decoding is successful, a process of checking whether the number of successive decoding successes including the success of decoding of the transmission period exceeds a predetermined threshold;
When the number of successive decoding successes exceeds the threshold, reducing the early decoding time by one unit time,
The process of determining whether to perform the early decoding in the transmission period,
The first power consumption gain is calculated through the sum of the second power consumption gain resulting from operating the wireless signal processor in the low power mode and the power consumption increase resulting from operating the decoder in the early decoding mode, and the first power consumption gain And determining to perform the early decoding in the transmission period when the reference value is exceeded. 7. The method of claim 6, wherein the number of successive decoding successes is measured in units of a transmission period. The method of claim 6,
A process of determining whether a predetermined decoding condition is satisfied every unit time from the early decoding time during the transmission period; and
And when the decoding condition is satisfied, decoding the signal received up to a corresponding unit time during the transmission period. delete delete delete delete delete delete delete delete In the power consumption reduction device through early decoding,
A wireless signal processing unit for receiving a wireless signal,
A baseband signal processing unit that processes an output signal of the wireless signal processing unit,
A decoder for decoding an output signal of the baseband signal processing unit,
Including a control unit,
The control unit,
At the start of the transmission period, it is determined whether to perform the early decoding in the transmission period according to the first power consumption gain obtained through the early decoding,
Determine whether a decoding condition predetermined in a unit time for decoding during the transmission period is satisfied,
When the decoding condition is satisfied, controlling the decoder to perform decoding on the signal received up to the unit time during the transmission period,
When the decoding is successful, the wireless signal processing unit is set to a low power mode for the remaining time period of the transmission period,
When the unit time is the last unit time of the transmission period, decoding is performed on the signal received through the wireless signal processing unit until the last unit time of the transmission period regardless of the decoding condition,
As part of an operation for determining whether to perform the early decoding in the transmission period,
The first power consumption gain is calculated through the sum of the second power consumption gain resulting from operating the wireless signal processor in the low power mode and the power consumption increase resulting from operating the decoder in the early decoding mode, and the first power consumption gain And determining to perform the early decoding in the transmission period when exceeding the reference value. In the power consumption reduction device through early decoding,
A wireless signal processing unit for receiving a wireless signal,
A baseband signal processing unit that processes an output signal of the wireless signal processing unit,
A decoder for decoding an output signal of the baseband signal processing unit,
Including a control unit,
The control unit,
At the start of the transmission period, it is determined whether to perform the early decoding in the transmission period according to the first power consumption gain obtained through the early decoding,
Perform decoding on the signal received up to an early decoding point in the transmission period,
When the decoding fails, controlling the decoder to perform decoding on the signal received until the next unit time within the transmission period,
When the decoding is successful, the wireless signal processing unit is set to a low power mode for the remaining time period of the transmission period,
When the decoding is successful, it is checked whether the number of successive decoding successes including the decoding success of the transmission period exceeds a predetermined threshold,
When the number of successive decoding successes exceeds the threshold, the early decoding time is reduced by one unit time,
As part of an operation of determining whether to perform the early decoding in the transmission period,
The first power consumption gain is calculated through the sum of the second power consumption gain resulting from operating the wireless signal processor in the low power mode and the power consumption increase resulting from operating the decoder in the early decoding mode, and the first power consumption gain And determining to perform the early decoding in the transmission period when exceeding the reference value. delete

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