Detailed Description
The embodiment of the invention provides a method for adjusting the speed of a voice encoder, which can enable an LTE system to support the speed self-adaption function of the voice encoder and is completely compatible with the existing system.
According to section 6.1.3 of 3GPP TS 36.321v8.6.0, the Media Access Control layer (MAC) of the base station (eNB) can transmit a MAC Control Element (MAC Control Element, MAC CE) to the User Equipment, i.e. the terminal (UE), to Control the behavior of the UE. The UE may also transmit the MAC CE to the eNB to apply for certain radio resources. According to this protocol, the process for enabling an LTE system to support vocoder rate adaptation, i.e., adjusting the vocoder rate, is as follows, see fig. 1:
step 101: the eNB generates a first control element that adjusts the speech coder rate.
Here, the MAC layer of the eNB generates a first control element for adjusting the vocoder rate, i.e., generates a MAC CE for the vocoder rate adaptation function, according to a higher layer or its own decision criterion. The format of the MAC CE may be any one of the formats shown in fig. 2(a), fig. 2(B) and fig. 2(c), that is, the MAC CE may include one or more reserved bits "R", a downlink adjustment bit "D", an uplink adjustment bit "U", and an AMR wideband or narrowband information bit "B", "WB", or "NB", although the MAC CE may further include a group of AMR rate information bits "Speed of Voice Codec" for specifying an AMR level that the UE should use; or may include one or more AMR rate adjustment bits "a" specifying an increase or decrease of one AMR level that the UE should use.
Step 102: the eNB transmits a first control element.
The MAC layer of the eNB transmits the MAC CE to the physical layer of the eNB, and the physical layer of the eNB transmits the MAC CE.
Here, when the MAC CE is a cell-level MAC CE, a Physical Downlink Shared Channel (PDSCH) is indicated by Downlink Control Information (DCI)1A, 1C or other DCI formats to carry the MAC CE, and a Physical Downlink Control Channel (PDCCH) corresponding to the PDSCH is placed in a common region of a Control Channel Element (CCE). Scrambling is performed using a cell load radio network temporary identity (CL-RNTI) or other radio network temporary identity for the cell-level PDCCH and the corresponding PDSCH. The CL-RNTI is represented by 16 bits, has a value range of 0-65535 and is specified by the eNB.
And when the MAC CE is the MAC CE for a single UE, indicating that the PDSCH carries the MAC CE by using DCI1A or other DCI formats, and placing the PDCCH corresponding to the PDSCH in a public area or a special area of the CCE. The PDCCH and corresponding PDSCH for a single UE are scrambled using a cell radio network temporary identity (C-RNTI) or other radio network temporary identity.
Step 103: the UE obtains a first control element.
Firstly, a physical layer of the UE searches a PDCCH for indicating the MAC CE information in a public area or a special area of a CCE, and then the UE decodes a PDSCH containing the MAC CE information according to the searched PDCCH for indicating the MAC CE information; finally, the MAC layer of the UE parses the MAC CE from the PDSCH.
Step 104: the UE adjusts the rate of the speech encoder according to the first control element.
Here, in the adjustment process, if it is an incremental adjustment and the maximum value or the minimum value has been reached, no adjustment is made.
Of course, in the embodiment of the present invention, the UE may also send a second control element requesting to adjust the rate of the speech encoder to the eNB, that is, the MAC layer of the UE transmits a MAC CE request to the eNB to change the rate of the speech encoder. The format of the MAC CE may be any one of those shown in fig. 2(a), 2(b), and 2 (c). Wherein the process of the UE transmitting the second control element to the eNB may occur before or after the above steps 101, 102, 103, 104.
The embodiments of the present invention will be described in further detail with reference to the drawings attached hereto.
In the first embodiment, the VoIP of the LTE uses AMR-NB, which now needs to adjust down one AMR rate level for the downlink of the whole cell, and the AMR rate of the UE has not yet reached the minimum value, wherein the PDCCH and PDSCH are scrambled using CL-RNTI. Referring to fig. 3, the process of adjusting the rate of the speech coder down includes:
step 301: the MAC layer of the eNB generates a MAC CE for a speech coder rate adaptation function according to a high-level or own judgment criterion. The format of the MAC CE is shown in fig. 2 (b).
In the MAC CE, "R" indicates a reserved bit, and "0" is assumed by default. "D" indicates that the downlink AMR rate level is operated, and if "1" is selected, it indicates that the eNB has an operation on the downlink AMR, otherwise, it has no operation. "U" indicates operating the uplink AMR rate level, and if "1" is taken, it indicates that the eNB has an operation on the uplink AMR, otherwise, it has no operation. "WB" indicates whether the MAC CE has an operation on AMR-WB, if "1" is taken, it indicates that eNB has an operation on AMR-WB, otherwise, it has no operation. "NB" indicates whether the MAC CE has operation for AMR-NB, if "1" is taken, it indicates that eNB has operation for AMR-NB, otherwise, it has no operation. "a" indicates rate adjustment and acts on both AMR-NB and AMR-WB, and if "1" is taken, it indicates that the AMR rate is down-regulated by one level, for example: from AMR12.2 to AMR 10.2; if "0" is taken, it means that the AMR rate is up-regulated by one level, for example: from AMR6.6 to AMR 8.85.
It can be assumed here that the eNB generated MAC CE "00010111" (binary value).
Step 302: the MAC layer of the eNB transmits the MAC CE to the physical layer of the eNB.
Step 303: the physical layer of the eNB transmits the MAC CE.
The MAC CE is a MAC CE for the cell level, and thus, the PDSCH can be indicated to carry the MAC CE by DCI1A, 1C, or other DCI formats, which is assumed to be DCI 1C.
The PDCCH corresponding to the PDSCH is placed in a common region of the CCE, and the PDCCH and the corresponding PDSCH are scrambled by using CL-RNTI. The eNB designates CL-RNTI as 65533, and the corresponding 16-ary value is 0x FFFD.
Step 304: the physical layer of the UE searches for a PDCCH indicating the MAC CE information in a common region or a dedicated region of the CCE, and descrambles the searched PDCCH using the CL-RNTI.
Step 305: and the UE decodes the PDSCH containing the MAC CE information according to the searched PDCCH indicating the MAC CE information. Also, CL-RNTI is used for descrambling during decoding.
Step 306: the MAC layer of the UE resolves the MAC CE "00010111".
Step 307: the UE adjusts the rate of the speech coder according to the MAC CE.
Here, since eNB places "1" in the "D" bit, it acts on the downlink AMR. Moreover, eNB sets "1" on "a" bit, and it can be seen that the AMR level is incremental adjustment, in this embodiment, the AMR rate of the UE has not yet reached the minimum value, so the UE down-regulates the rate of the speech encoder by one level.
Of course, in this embodiment, the MAC layer of the UE may also transmit a MAC CE request to the eNB to change the rate of the speech encoder. The format of the MAC CE may be as shown in fig. 2 (a). The transmission process is independent of steps 301 to 307 and may occur before or after any of them.
In the second embodiment, the VoIP of LTE uses AMR-WB, and a downlink AMR rate level needs to be assigned for a single UE, wherein the PDCCH and PDSCH are scrambled using C-RNTI. Referring to fig. 4, the process of adjusting the speech coder rate includes:
step 401: the MAC layer of the eNB generates a MAC CE for a speech coder rate adaptation function according to a high-level or own judgment criterion. The format of the MAC CE is shown in fig. 2 (a).
In the MAC CE, "R" indicates a reserved bit, and "0" is assumed by default. "D" indicates that the downlink AMR rate level is operated, and if "1" is selected, it indicates that the eNB has an operation on the downlink AMR, otherwise, it has no operation. "U" indicates operating the uplink AMR rate level, and if "1" is taken, it indicates that the eNB has an operation on the uplink AMR, otherwise, it has no operation. "B" indicates whether the MAC CE is for AMR-WB or AMR-NB, and if "1" is taken, it indicates that the eNB operates on AMR-WB, otherwise, it operates on AMR-NB. The AMR rate information "Speed of Voice Codec" represents the rate class of AMR, and the specific format can be as shown in table 3:
TABLE 3
Here, assuming that the eNB is to set the AMR level of the UE to narrowband AMR7.95, one MAC CE is generated to be "00010101".
Step 402: the MAC layer of the eNB transmits the MAC CE to the physical layer of the eNB.
Step 403: the physical layer of the eNB transmits the MAC CE.
Since the MAC CE is a MAC CE for a single UE, the PDSCH is indicated to carry the MAC CE by DCI1A or other DCI formats, and it is assumed here that the PDSCH is indicated by DCI 1A. The corresponding PDCCH is placed in the dedicated region of the CCE. The PDCCH and the corresponding PDSCH are scrambled using the C-RNTI.
Step 404: the physical layer of the UE searches for a PDCCH indicating the MAC CE information in a common region or a dedicated region of the CCE. And uses the C-RNTI to descramble the descrambled and searched PDCCH.
Step 405: and the UE decodes the PDSCH containing the MAC CE information according to the searched PDCCH indicating the MAC CE information. Also, the C-RNTI is used for descrambling during decoding.
Step 406: the MAC layer of the UE resolves the MAC CE "00010101".
Step 407: the UE adjusts the rate of the speech coder according to the MAC CE.
Since eNB sets "1" on "D" bit, it acts on the downlink AMR; since eNB puts "0" on the "B" bit, it indicates that there is an operation on AMR-WB, using absolute value adjustment and AMR level of "0101", with its corresponding decimal value of 5, according to table 3, the UE sets the rate of the speech encoder to narrowband AMR 7.95.
Step H: the MAC layer of the UE transmits a MAC CE request to the eNB to change the rate of the speech encoder. The format of the MAC CE is shown in fig. 1.
Of course, in this embodiment, the MAC layer of the UE may also transmit a MAC CE request to the eNB to change the rate of the speech encoder. The format of the MAC CE may be as shown in fig. 2 (a). This transmission process is independent of steps 401 through 407 and may occur before or after either.
The LTE system supporting the speech coder rate adaptation function includes a base station and a terminal, wherein,
a base station for generating a first control element for adjusting a speech coder rate, transmitting said first control element.
And the terminal is used for adjusting the speed of the voice coder according to the first control element.
When the first control element is a control element for a cell level, the base station is further configured to indicate the PDSCH to carry the first control element by DCI1A or 1C or other DCI formats, place the PDCCH corresponding to the PDSCH in a common region of the CCE, and scramble the PDCCH and the corresponding PDSCH by using CL-RNTI or other radio network temporary identifiers.
When the first control element is a control element for a single terminal, the base station is further configured to indicate the PDSCH to carry the first control element by DCI1A or other DCI formats, place the PDCCH corresponding to the PDSCH in a common region or a dedicated region of a CCE, and scramble the PDCCH and the corresponding PDSCH by using a C-RNTI or other radio network temporary identifier.
The terminal is further configured to search a PDCCH indicating the first control element information in a common region or a dedicated region of the CCE, decode a PDSCH including the first control element information according to the PDCCH, and parse the first control element from the PDSCH.
Of course, in the system for adjusting the rate of the speech encoder according to the embodiment of the present invention, the terminal may further send a second control element requesting to adjust the rate of the speech encoder to the base station.
Referring to fig. 5, a base station in an LTE application system includes: a generating unit 510 and a transmitting unit 520. Wherein,
a generating unit 510 is configured to generate a first control element for adjusting the rate of the speech encoder.
A transmitting unit 520, configured to transmit the first control element.
When the first control element is a control element for a cell level, the transmitting unit 520 uses DCI format 1A or 1C or other DCI formats to indicate a PDSCH of a physical downlink shared channel to carry the first control element, places a PDCCH corresponding to the PDSCH in a common region of the CCE, and scrambles the PDCCH and the corresponding PDSCH using CL-RNTI or other radio network temporary identifiers.
When the first control element is a control element for a single terminal, the transmitting unit 520 uses DCI1A or other DCI formats to indicate that the PDSCH carries the first control element, places the PDCCH corresponding to the PDSCH in a common region or a dedicated region of a CCE, and scrambles the PDCCH and the corresponding PDSCH using a C-RNTI or other radio network temporary identifier.
Referring to fig. 6, a terminal in an LTE application system includes: an acquisition unit 610 and an adjustment unit 620. Wherein,
the obtaining unit 610 is configured to obtain a first control element that is issued by a base station and used for adjusting a rate of a speech encoder.
An adjusting unit 620, configured to adjust a rate of the speech encoder according to the first control element.
The obtaining unit 610 first searches a PDCCH indicating the first control element information in a common region or a dedicated region of a CCE, then decodes a PDSCH including the first control element information according to the PDCCH, and parses the first control element from the PDSCH.
Of course, in the embodiment of the present invention, the terminal further includes: a sending unit, configured to send a second control element requesting to adjust a rate of a speech encoder to the base station.
In summary, in the process of adjusting the speed of the speech encoder in the LTE system according to the embodiment of the present invention, the base station generates the first control element for adjusting the speed of the speech encoder, and transmits the first control element, so that the terminal adjusts the speed of the speech encoder according to the first control element, and thus, the LTE system can obtain higher system capacity and improve higher service instructions, so that the LTE system well supports the speed adaptive function of the speech encoder, and is completely compatible with the existing system.
It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is intended to include such modifications and variations.