Disclosure of Invention
The inventor finds that, in narrowband communication, one problem to be studied is to support smaller scheduling granularity (granularity) to adapt to the characteristic that NB-IOT technology has a small data volume and serves more UEs at the same time. A direct method is to change the minimum unit of data transmission scheduling from one PRB pair to one subcarrier, and therefore, an IE (Information Element) of an original DCI (Downlink Control Indication) Format for Enhanced Machine Type Communication (eMTC) data scheduling needs to be added to an Indication of the subcarrier.
The inventor has found through research that the indication of directly introducing the sub-carriers brings two problems:
the first problem is that a PRB pair contains 12 subcarriers, and 12-bit IEs are needed to completely indicate that the subcarriers in the 12 subcarriers are scheduled, which greatly increases redundancy of system control signaling and brings huge control signaling overhead to the NB-IOT system.
The second problem, because the RF (Radio Frequency) capability of an NB-IOT user is only 180kHz at maximum. Thus, if all three users need to occupy 120kHz resources, they can only be scheduled on three different PRB pairs, and cannot share 2 PRB pairs, as described above. Since a 12-bit subcarrier indication can only be valid in one PRB, it cannot span different PRBs.
In view of the above problems, the present invention provides a corresponding solution. It should be noted that, without conflict, the embodiments and features in the embodiments in the UE (User Equipment) of the present application may be applied to the base station, and vice versa. Further, the embodiments and features of the embodiments of the present application may be arbitrarily combined with each other without conflict.
The invention discloses a method in a base station supporting narrow-band wireless communication, which comprises the following steps:
-step a. transmitting first signalling, the first signalling indicating a first set of frequency domain resources.
-step b. sending a second signaling, the second signaling scheduling data transmission on the target time-frequency resource.
Step c. transmitting downlink data on the target time frequency resource and the downlink data is scheduled by the second signaling, or receiving uplink data on the target time frequency resource and the uplink data is scheduled by the second signaling.
Wherein the first signaling is higher layer signaling. The second signaling is physical layer signaling or the second signaling is higher layer signaling. The second signaling indicates a target frequency domain resource from a first frequency domain resource set, the target frequency domain resource is a frequency domain resource occupied by the target time frequency resource in a target time window, and the first frequency domain resource comprises N basic frequency domain units. The N is a positive integer, and the frequency band occupied by the basic frequency domain unit does not exceed 180 kHz. The target time window is the first time window occupied by the target time frequency resource in the time domain. The target time frequency resource occupies L time windows in the time domain. L is a positive integer.
In the above method, the second signaling indicates the target frequency domain resource from the first set of frequency domain resources, thereby reducing the redundant Overhead (Overhead) of the second signaling. Furthermore, considering that the RF capability of the UE is likely to only support a bandwidth of one basic frequency domain unit, the method enables the UE to perform channel estimation only in the first frequency domain resource set in a time division manner, thereby avoiding the UE from performing channel estimation on the broadband resource and improving the performance of channel estimation.
As an embodiment, the basic frequency domain unit corresponds to a bandwidth of one PRB.
As an embodiment, the basic frequency domain unit corresponds to a bandwidth of one subcarrier.
As a sub-embodiment of this embodiment, the bandwidth of the one sub-carrier is one of {3.75kHz, 15kHz }.
As an embodiment, L is greater than 1, and frequency domain resources occupied by the target time-frequency resource in adjacent time windows are different.
As an embodiment, L is greater than 1, and frequency domain resources occupied by the target time-frequency resource in different time windows are the same.
As an example, L is equal to 1.
As an embodiment, the first set of frequency domain resources is used for downlink transmission, and the length of the time window is 1 ms.
As an embodiment, the first set of frequency domain resources is for uplink transmission, and the length of the time window is one of {4ms,6ms }.
As an embodiment, the first signaling is RRC (Radio Resource Control) specific signaling.
As an embodiment, the first signaling is RRC common signaling.
As an embodiment, the second signaling is physical layer signaling.
As an embodiment, the N basic frequency domain units are contiguous in the frequency domain.
As one embodiment, the N fundamental frequency domain units are discrete in the frequency domain.
Specifically, according to an aspect of the present invention, the step a further includes the steps of:
step A0. sends a third signaling indicating the second set of frequency domain resources.
Wherein the second set of frequency domain resources comprises Q basic frequency domain units. Q is a positive integer, and Q is greater than or equal to N. The frequency domain resources occupied by the first set of frequency domain resources are a subset of the frequency domain resources occupied by the second set of frequency domain resources.
As an embodiment, the third signaling is system information.
As an embodiment, the Q fundamental frequency domain units are contiguous in the frequency domain.
As one embodiment, the Q fundamental frequency domain units are discrete in the frequency domain.
Specifically, according to an aspect of the present invention, the target time-frequency resource occupies K consecutive subcarriers within the target time window. K is a positive integer no greater than 12. The second signaling indicates one of:
-a first subcarrier and said K
-a second subcarrier and said K
-a first subcarrier and a second subcarrier
The first subcarrier is a subcarrier with the lowest center frequency among subcarriers included in the target frequency domain resource, and the second subcarrier is a subcarrier with the highest center frequency among subcarriers included in the target frequency domain resource.
As one embodiment, K is equal to 1 and the second signaling contains only the first subcarrier.
As an embodiment, the K consecutive subcarriers belong to one basic frequency domain unit, and a frequency band occupied by the basic frequency domain unit is 180 kHz.
As an embodiment, the K consecutive subcarriers belong to two frequency-domain consecutive basic frequency-domain units, and a frequency band occupied by the basic frequency-domain units is 180kHz, and a frequency band occupied by the K consecutive subcarriers is not greater than 180 kHz.
As an embodiment, the second signaling is further used to indicate the number L1 of the time window occupied by one transmission of the data channel carried by the target time-frequency resource. Wherein L1 is a positive integer and L is divisible by L1. The data channels are non-repeating over the L1 time windows.
In particular, according to one aspect of the invention, it is characterized in that the first signaling indicates the first set of frequency domain resources from among the second set of frequency domain resources.
As an embodiment, the indexes of the N basic frequency domain units occupied by the first frequency domain resource set in the Q basic frequency domain units occupied by the second frequency domain resource set are consecutive.
As an embodiment, the indexes of the N basic frequency domain units occupied by the first frequency domain resource set in the Q basic frequency domain units occupied by the second frequency domain resource set are discrete.
Specifically, according to one aspect of the present invention, it is characterized in that the second signaling indicates the first subcarrier and the second signaling indicates the first subcarrier from the N basic frequency domain units; or the second signaling indicates the second subcarrier and the second signaling indicates the second subcarrier from the N basic frequency domain units.
As one embodiment, the basic frequency domain unit includes S subcarriers. The second signaling is used for indicating that the information bit number of the K subcarriers is equal to R. R is a positive integer and is equal to
One of (1). Wherein,
represents a positive integer not greater than W + 1.
Specifically, according to an aspect of the present invention, the step a further includes the steps of:
-a step a1. sending a fourth signaling, the fourth signaling indicating a third set of frequency domain resources.
And the frequency domain resources occupied by the third frequency domain resource set do not exceed 180kHz, and the second signaling is transmitted in the third frequency domain resource set.
As an embodiment, the frequency domain resources occupied by the third frequency domain resource set include D basic frequency domain units. D is a positive integer.
As a sub-embodiment of this embodiment, the fourth signaling is a synchronization sequence, and D is equal to 1. The fourth signaling indicates that the third frequency domain resource set is a basic frequency domain unit with the same occupation of the fourth signaling and the third frequency domain resource, and the UE determines the frequency domain position of the third frequency domain resource by detecting the fourth signaling.
As a sub-embodiment of this embodiment, the fourth signaling is one of { broadcast signaling, RRC dedicated signaling }.
As a sub-embodiment of this embodiment, the D basic frequency domain units are contiguous in the frequency domain.
As a sub-embodiment of this embodiment, the D fundamental frequency domain units are discrete in the frequency domain.
In particular, according to an aspect of the invention, it is characterized in that the fourth signaling indicates the third set of frequency domain resources from among the second set of frequency domain resources.
As an embodiment, the indexes of the D basic frequency domain units occupied by the third frequency domain resource set in the Q basic frequency domain units occupied by the second frequency domain resource set are continuous.
As an embodiment, the indexes of the D basic frequency domain units occupied by the third frequency domain resource set in the Q basic frequency domain units occupied by the second frequency domain resource set are discrete.
One peculiarity of the invention lies in that the first frequency domain resource set is indicated by the first signaling, and the time frequency resource position occupied by the data scheduled to the UE is further indicated in the first frequency domain resource set by the dynamic scheduling signaling of the UE, namely the second signaling. Therefore, downlink and uplink data scheduling can be realized by using fewer DCI information bits, and the redundancy of system control signaling is reduced. Meanwhile, because the RF capability of the NB-IOT UE is limited, the scheduling flexibility does not need to cover the whole system bandwidth, therefore, the first signaling is sent by adopting the high-level signaling, the scheduling characteristic of the NB-IOT UE can be well adapted, and the performance can not be influenced. On the other hand, the minimum scheduling granularity in the second signaling is a subcarrier instead of the traditional PRB, so that the base station is ensured to schedule more users on limited resources in a time window, the characteristics of multiple users and small data volume of NB-IOT service can be better adapted, and the overall spectrum efficiency of the system is improved.
At the same time, another peculiarity of the invention consists in indicating in the second set of frequency domain resources the first set of frequency domain resources in which the target time frequency resources are indicated. The indication based on the subset instead of the system frequency band can greatly reduce signaling overhead, particularly dynamic signaling overhead, and improve the overall spectrum efficiency of the system.
The invention discloses a method in UE supporting narrow-band communication, which comprises the following steps:
-step a. receiving first signalling, the first signalling indicating a first set of frequency domain resources.
-step b. receiving a second signaling, the second signaling scheduling data transmission on the target time-frequency resource.
And C, receiving downlink data on the target time frequency resource according to the scheduling of the second signaling, or sending uplink data on the target time frequency resource according to the scheduling of the second signaling.
Wherein the first signaling is higher layer signaling. The second signaling is physical layer signaling or the second signaling is higher layer signaling. The second signaling indicates a target frequency domain resource from a first frequency domain resource set, the target frequency domain resource is a frequency domain resource occupied by the target time frequency resource in a target time window, and the first frequency domain resource comprises N basic frequency domain units. The N is a positive integer, and the frequency band occupied by the basic frequency domain unit does not exceed 180 kHz. The target time window is the first time window occupied by the target time frequency resource in the time domain. The target time frequency resource occupies L time windows in the time domain. L is a positive integer.
As an embodiment, the method further includes the steps of:
-step A0. the UE performs channel estimation in the first set of frequency domain resources.
As a sub-embodiment of the above embodiment, the UE can only receive a downlink RS (Reference Signal) in one basic frequency domain unit in one time window, and the downlink RS is used for channel estimation.
Specifically, according to an aspect of the present invention, the step a further includes the steps of:
step A0. receives third signaling indicating the second set of frequency domain resources.
Wherein the second set of frequency domain resources comprises Q basic frequency domain units. Q is a positive integer, and Q is greater than or equal to N. The frequency domain resources occupied by the first set of frequency domain resources are a subset of the frequency domain resources occupied by the second set of frequency domain resources.
Specifically, according to an aspect of the present invention, the target time-frequency resource occupies K consecutive subcarriers within the target time window. K is a positive integer no greater than 12. The second signaling indicates one of:
-a first subcarrier and said K
-a second subcarrier and said K
-a first subcarrier and a second subcarrier
The first subcarrier is a subcarrier with the lowest center frequency among subcarriers included in the target frequency domain resource, and the second subcarrier is a subcarrier with the highest center frequency among subcarriers included in the target frequency domain resource. In particular, according to one aspect of the invention, it is characterized in that the first signaling indicates the first set of frequency domain resources from among the second set of frequency domain resources.
In particular, according to one aspect of the invention, it is characterized in that the first signaling indicates the first set of frequency domain resources from the second set of frequency domain resources.
Specifically, according to one aspect of the present invention, it is characterized in that the second signaling indicates the first subcarrier and the second signaling indicates the first subcarrier from the N basic frequency domain units; or the second signaling indicates the second subcarrier and the second signaling indicates the second subcarrier from the N basic frequency domain units.
Specifically, the step a is characterized by further comprising the following steps:
step a1. receiving a fourth signaling, the fourth signaling indicating a third set of frequency domain resources.
And the frequency domain resources occupied by the third frequency domain resource set in the third time window are not more than 180kHz, and the second signaling is transmitted in the third frequency domain resource set.
As an embodiment, the UE detects the second signaling in the third set of resources.
The invention discloses a base station device supporting narrow-band wireless communication, which is characterized by comprising:
-a first module: for transmitting first signaling, the first signaling indicating a first set of frequency domain resources; and for transmitting third signaling, the third signaling indicating a second set of frequency domain resources; and means for transmitting fourth signaling, the fourth signaling indicating the third set of frequency domain resources.
-a second module: for sending a second signaling, which schedules data transmission on the target time-frequency resource.
-a third module: and the first signaling is used for sending downlink data on the target time frequency resource, and the downlink data is scheduled by the second signaling, or the second signaling is used for receiving uplink data on the target time frequency resource, and the uplink data is scheduled by the second signaling.
Wherein the first signaling is higher layer signaling. The second signaling is physical layer signaling or the second signaling is higher layer signaling. The second signaling indicates a target frequency domain resource from a first frequency domain resource set, the target frequency domain resource is a frequency domain resource occupied by the target time frequency resource in a target time window, and the first frequency domain resource comprises N basic frequency domain units. The N is a positive integer, and the frequency band occupied by the basic frequency domain unit does not exceed 180 kHz. The target time window is the first time window occupied by the target time frequency resource in the time domain. The target time frequency resource occupies L time windows in the time domain. L is a positive integer. The second set of frequency domain resources comprises Q basic frequency domain units. Q is a positive integer, and Q is greater than or equal to N. The frequency domain resources occupied by the first set of frequency domain resources are a subset of the frequency domain resources occupied by the second set of frequency domain resources. The frequency domain resources occupied by the third frequency domain resource set do not exceed 180kHz, and the second signaling is transmitted in the third frequency domain resource set.
Specifically, according to an aspect of the present invention, the target time-frequency resource occupies K consecutive subcarriers within the target time window. K is a positive integer no greater than 12. The second signaling indicates one of:
-a first subcarrier and said K
-a second subcarrier and said K
-a first subcarrier and a second subcarrier
The first subcarrier is a subcarrier with the lowest center frequency among subcarriers included in the target frequency domain resource, and the second subcarrier is a subcarrier with the highest center frequency among subcarriers included in the target frequency domain resource.
The invention discloses a user equipment supporting narrow-band wireless communication, which is characterized by comprising:
-a first module: for receiving first signaling, the first signaling indicating a first set of frequency domain resources; and means for receiving third signalling, the third signalling indicating a second set of frequency domain resources; and means for receiving fourth signaling, the fourth signaling indicating a third set of frequency domain resources.
-a second module: for receiving second signaling, the second signaling scheduling data transmission on the target time-frequency resource.
-a third module: and the receiving unit is used for receiving downlink data on the target time-frequency resource according to the scheduling of the second signaling, or is used for sending uplink data on the target time-frequency resource according to the scheduling of the second signaling.
Wherein the first signaling is higher layer signaling. The second signaling is physical layer signaling or the second signaling is higher layer signaling. The second signaling indicates a target frequency domain resource from a first frequency domain resource set, the target frequency domain resource is a frequency domain resource occupied by the target time frequency resource in a target time window, and the first frequency domain resource comprises N basic frequency domain units. The N is a positive integer, and the frequency band occupied by the basic frequency domain unit does not exceed 180 kHz. The target time window is the first time window occupied by the target time frequency resource in the time domain. The target time frequency resource occupies L time windows in the time domain. L is a positive integer. The second set of frequency domain resources comprises Q basic frequency domain units. Q is a positive integer, and Q is greater than or equal to N. The frequency domain resources occupied by the first set of frequency domain resources are a subset of the frequency domain resources occupied by the second set of frequency domain resources. The frequency domain resources occupied by the third frequency domain resource set do not exceed 180kHz, and the second signaling is transmitted in the third frequency domain resource set.
Specifically, according to an aspect of the present invention, the target time-frequency resource occupies K consecutive subcarriers within the target time window. K is a positive integer no greater than 12. The second signaling indicates one of:
-a first subcarrier and said K
-a second subcarrier and said K
-a first subcarrier and a second subcarrier
The first subcarrier is a subcarrier with the lowest center frequency among subcarriers included in the target frequency domain resource, and the second subcarrier is a subcarrier with the highest center frequency among subcarriers included in the target frequency domain resource.
Compared with the prior art, the invention has the following technical advantages:
indicating a first set of frequency domain resources by a first signaling, and then indicating, by a second signaling, a time-frequency resource location occupied by data scheduled to the UE in the first set of frequency domain resources. And under the condition of not influencing the NB-IOT scheduling performance, the redundancy of control signaling is reduced.
The minimum granularity of scheduling in the second signaling is a subcarrier, instead of the conventional PRB, so that it is ensured that the base station schedules more users on limited resources within a time window, and the method can better adapt to the characteristics of multiple users and small data volume in NB-IOT services, and improve the overall spectrum efficiency of the system.
Indicating a first set of frequency domain resources in the second set of frequency domain resources, indicating target time-frequency resources in the first set of frequency domain resources. The indication based on the subset instead of the system frequency band can greatly reduce signaling overhead, particularly dynamic signaling overhead, and improve the overall spectrum efficiency of the system.
Improving the channel estimation performance.
Embodiment 3 shows a schematic diagram of the frequency domain positions of a positive integer number of basic frequency domain units constituting a given set of frequency domain resources according to the present invention; as shown in fig. 3. Wherein the given set of frequency domain resources is one of { a first set of frequency domain resources, a second set of frequency domain resources, a third set of frequency domain resources };
as shown in fig. 3, a basic frequency domain unit #1 to a basic frequency domain unit # I are drawn.
As an embodiment, the I basic frequency domain units of the basic frequency domain unit #1 to the basic frequency domain unit # I constitute a system bandwidth.
As an embodiment, of the basic frequency domain units #1 to # I, M basic frequency domain units constitute a given set of frequency domain resources. And the frequency domain positions of the M basic frequency domain units are indicated by given signaling. Wherein the given signaling is one of { first signaling, third signaling, fourth signaling }. M is a positive integer.
As a sub-embodiment, M is equal to N, and the given set of frequency domain resources is a first set of frequency domain resources, and the given signaling is a first signaling.
As a sub-embodiment, M is equal to Q, and the given set of frequency domain resources is a second set of frequency domain resources, and the given signaling is a third signaling.
As a sub-embodiment, M is equal to D, and the given set of frequency domain resources is a third set of frequency domain resources, and the given signaling is a fourth signaling.
As a sub-embodiment, N is equal to 1.
As a sub-embodiment, D is equal to 1.
As a sub-embodiment, Q is equal to 1.
As a sub-embodiment, the M basic frequency domain units are contiguous in the frequency domain, and the given signaling includes at least one of:
-a starting frequency point of a lowest frequency basic frequency domain unit of the M basic frequency domain units;
-a starting frequency point of a highest frequency basic frequency domain unit of the M basic frequency domain units;
-an index in the overall system bandwidth of PRBs occupied by the lowest frequency basic frequency domain unit of the M basic frequency domain units;
-an index in the overall system bandwidth of PRBs occupied by the highest frequency basic frequency domain unit of the M basic frequency domain units;
-the value of M;
as a sub-embodiment, the M basic frequency domain units are discrete in the frequency domain, and the given signaling includes at least one of:
-a starting frequency point for an mth of the M basic frequency domain units;
-an index in the overall system bandwidth of PRBs occupied by the mth of the M basic frequency domain units;
wherein M is a positive integer not less than M.
As an embodiment, of the basic frequency domain units #1 to # I, M basic frequency domain units constitute a given set of frequency domain resources, and Q basic frequency domain units constitute a second set of frequency domain resources. And the frequency domain positions of the M basic frequency domain units are indicated by the given signaling from the second frequency domain resource. Wherein the given signaling is one of { first signaling, fourth signaling }. M is a positive integer.
As a sub-embodiment, M is equal to N, and the given set of frequency domain resources is a first set of frequency domain resources, and the given signaling is a first signaling.
As a sub-embodiment, M is equal to D, and the given set of frequency domain resources is a third set of frequency domain resources, and the given signaling is a fourth signaling.
As a sub-embodiment, the indexes of the M basic frequency domain units in the Q basic frequency domain units are consecutive, and the given signaling includes at least one of:
-an index of a lowest of the M elementary frequency-domain units in the Q elementary frequency-domain units;
-an index of the highest of the M elementary frequency-domain units in the Q elementary frequency-domain units;
-the value of M;
as a sub-embodiment, the indexes of the M basic frequency domain units in the Q basic frequency domain units are discrete, and the given signaling includes at least one of:
-an index of an mth of the M basic frequency domain units in the Q basic frequency domain units;
wherein M is a positive integer not less than M.