HK1164021B - Method and apparatus for communication - Google Patents

Description

Method and apparatus for communication

Technical Field

The present application relates generally to methods and apparatus for neighbor cell transmission frame allocation signaling in an environment such as a fourth generation (4G) network.

Background

As part of normal operation, a User Equipment (UE) may need to periodically collect various measurements of neighbor cells and its base stations within its reception range to assist in supporting operations such as tuning or handover of signals, among others. According to certain protocols, such measurements will be performed on specifically designated reference signals. Therefore, it would be advantageous for the UE to have more accurate information of neighbor cell resource allocation and to obtain improved measurement collection from implicit reference symbol positions therein.

Disclosure of Invention

Various aspects of examples of the invention are set out in the claims.

According to a first aspect of the present invention, a method comprises receiving, at a base station, an indication of a first resource allocation in each of one or more neighbor base stations, and transmitting to at least one associated user equipment a message comprising a second indication indicating whether the first resource allocation of the one or more neighbor base stations is a subset of a second resource allocation of the base station.

According to a second aspect of the invention, an apparatus comprises: a first module configured to receive, at a base station, an indication of a first resource allocation in each of one or more neighbor base stations; and a second module configured to transmit a message to at least one user equipment including a second indication indicating whether the first resource allocation of one or more neighbor base stations is a subset of the second resource allocation of the base station.

According to a third aspect of the invention, a system comprises: a first apparatus configured to receive, at a base station, an indication of a first resource allocation in each of one or more neighbor base stations; and transmitting a message to at least one associated user equipment including a second indication indicating whether the first resource allocation of one or more neighbor base stations is a subset of the second resource allocation of that base station; and a second apparatus configured to receive the message from the first apparatus; and performing one or more measurements based on the second indication.

Drawings

For a more complete understanding of example embodiments of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:

FIG. 1 illustrates an example wireless system;

FIG. 2 illustrates a portion of an example resource control module in a base station;

FIG. 3 illustrates an example method of transmitting a neighbor cell configuration message to at least one related UE;

figure 4 illustrates an example neighbor cell resource allocation map; and

figure 5 illustrates an example method of collecting measurements based on a search subset of neighbor cell resource allocations.

Detailed Description

The following figures 1 through 5, and the various embodiments used to describe the principles disclosed in this patent document, are by way of illustration only and should not be construed in any way to limit the scope of the invention. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any type of suitably arranged device or system.

Fig. 1 illustrates an example wireless system 100, the wireless system 100 including a serving cell 102, a first neighbor cell 104A, a second neighbor cell 2104B, a third neighbor cell 104C, and a User Equipment (UE) 112. Neighbor cell 104A has a Base Station (BS) and an associated transmission tower 106A. Likewise, neighbor cells 104B and 104C may have associated base stations 106B and 106C, respectively. The UE 112 is served by a serving cell 102, the serving cell 102 having a serving base station 108. A UE such as UE 112 may need to be covered by at least one cell. For purposes of this disclosure, neighbor cells 104A-C and associated base stations may be considered to perform similar functions and thus may be interchanged with one another without any ambiguity in context.

The serving cell 102 may broadcast restricted information about the transmission frame assignments from its neighbor cells (e.g., 104A-C) as compared to transmission frames from the serving cell 102 itself. The transmission frame may include one or more reference signals for purposes such as measurement. In one embodiment, the serving cell 102 may receive signaling over a Multimedia Broadcast Single Frequency Network (MBSFN) subframe allocation from 104B and 104C. The UE 112 may obtain an indication of a channel estimate based on measurements of reference signals in transmission frames from neighbor cells such as 104A. Since some transmission frames are non-MBSFN subframes, each of the neighbor cells 104A-C may broadcast restricted information about MBSFN subframe allocation compared to those in the neighbor cells 104A-C, thereby allowing at least time-efficient measurements. The MBSFN subframe may be a regular MBSFN subframe or a blank subframe that is a variant of the regular MBSFN subframe and does not contain any control symbols.

The UE 112 may receive a broadcast configuration for measurements to support mobile services between cells in a wireless network, such as a 3G network and a Long Term Evolution (LTE) network. The UE 112 may collect channel measurements configured by the wireless network, thereby collecting the distance and strength of the channels to the serving cell 102 and the neighbor cells 104A-C, and also monitoring certain measurement thresholds. In one embodiment, the UE 112 is in an active state indicated by a Radio Resource Control (RRC) connected state and has an active connection to the serving cell 102. At this point, UE 112 may report the monitoring results to the network through serving cell 102, allowing the network to make handover decisions. When the UE 112 is in an idle state, channel measurements may assist in defining when the UE 112 may need to change the cell that the UE 112 is currently monitoring. The UE 112 may be one of a 3G mobile station, a 4G mobile station, and a mobile computing device.

The serving base station 108 in the serving cell 102 may have a resource control module 200 configured to communicate with the neighbor cells 104A-C and associated UEs 112 for radio resource management purposes. More details regarding the resource control module 200 are illustrated and described, respectively, with respect to FIG. 2.

In one embodiment, the wireless network system 100 may be a UMTS Terrestrial Radio Access Network (UTRAN) of LTE, or an E-UTRAN, which may support Multimedia Broadcast Multicast Service (MBMS) and Multimedia Broadcast Single Frequency Network (MBSFN) operation. The wireless network system 100 may achieve macro diversity gain by transmitting the same signal from the base stations 106A-C and 108. MBMS may be provided on a dedicated MBMS frequency layer or a mixed layer, where unicast transmissions (including single cell MBMS content) may be time multiplexed with MBSFN transmissions on the same frequency layer. In the latter example, MBSFN transmissions may occupy dedicated subframes with a fixed interval (e.g., 1 millisecond) into which LTE transmissions are partitioned. The structure of the dedicated subframe may be different from the general unicast subframe in terms of cyclic prefix and reference signal. Due to the above differences, the first OFDM symbol of the MBSFN subframe may contain reference signals, which are also transmitted within some intermediate symbols of the general unicast subframe. Neighbor cells 104A-C may have different MBSFN subframe allocations depending on the radio resource allocation configured for MBSFN subframe transmission.

UE 102 may need to measure cells, e.g., 104A, in those subframes, e.g., base unicast subframes, that have a higher density of reference signals in order to obtain a more accurate channel estimate. A cell, e.g., serving cell 102, may employ the cell neighbor cell configuration defined in the RRC protocol to transmit limited information related to neighbor cell resource allocation information. The cell neighbor cell configuration may be periodically broadcast every few hundred milliseconds in the system information block and may also be sent by a hub (e.g., base station 108) in dedicated signaling to configure the measurement behavior of the UE 112.

Fig. 2 illustrates a portion of one example resource control module 200 within the base station 108 of fig. 1. The resource control module may include a control module 214 and an interface module 216. The interface module 216 may be configured to communicate with the UE 112 and the neighbor cells 104A-C for resource control signaling.

The control module 214 may be configured to collect indications of neighbor cell resource allocations in the neighbor cells 104A-C and generate a neighbor cell resource allocation map based on one or more resource allocation indications. The resource allocation map may be a conceptualized representation of the overall situation of neighbor cell resource allocation. More details of the resource allocation map are illustrated and described separately in fig. 4. The control module 214 may also be configured to generate a search subset of neighbor resource allocations based on the neighbor cell resource allocation map. The search subset is a subset of all transmission frame allocations from neighbor cells 140A-C and may more accurately define the resource allocation used by UE 112 to collect the UE's measurements. The control module 214 may also be configured to establish a neighbor cell configuration message that includes a search subset of the neighbor resource allocation to be sent to the UE 112 through the interface module 216.

Fig. 3 illustrates one example method 300 for transmitting a search subset of neighbor cell resource allocations to a UE 112. The method 300 may include: at block 302, an indication of neighbor resource allocation in each of one or more neighbor cells is received at a serving base station 108, a resource allocation map is generated at block 304, a search subset of the neighbor cell resource allocation is generated at block 306, a neighbor cell configuration notification message is established at block 308, and the neighbor cell configuration message is transmitted to at least one UE, e.g., UE 102.

Receiving a resource allocation indication regarding neighbor cell resource allocation at block 301 may include: broadcast messages are received from each neighbor cell 104A-C regarding MBSFN subframe allocation and other types of channel allocation at the serving cell 102. Receiving a resource allocation indication regarding neighbor cell resource allocation at block 301 may further comprise: indications of MBSFN subframe allocations in neighbor cells 104A-C are received from other sources, e.g., a network center. The resource allocation indication may be received via a signaling protocol such as X1, for example, as defined in the LTE standard specification, or other suitable signaling protocol.

Generating the neighbor cell resource allocation map at block 304 may include: a neighbor resource allocation map is generated based on the received resource allocation indication. Generating the neighbor cell resource allocation map at block 304 may further comprise: the indications from the neighbor cells 104A-C are aggregated into an overall logical view of the neighbor cell resource allocations. The resource allocation may be one transmission frame allocation that references a transmission frame allocation at the serving cell 102.

Generating the search subset of neighbor resource allocations at block 306 may include: the information in the neighbor cell resource allocation map is summarized and the summarized information is translated into an expression of a search subset. An example of an expression to search for subsets is a bitmap representation. The search subset may represent a more accurate search space for the UE 112 to perform channel searches and collect various measurements. In one embodiment, the allocation of MBSFN subframes is a channel resource allocation to be monitored and searched by UE 112. Generating the search subset of neighbor resource allocations at block 306 may further comprise: generating a bitmap indicator for representing the narrowed search subset in the following manner:

00: not all neighbor cells 104A-C with MBSFN subframe allocation have the same MBSFN subframe allocation as the serving cell 102 or a subset thereof; and

10: all neighbor cells 104A-C with MBSFN subframe allocations have the same MBSFN subframe allocation as the serving cell 102 or a subset thereof.

Establishing the neighbor cell configuration message at block 308 may involve creating a protocol information element, such as a neighbor cell configuration specified in the RRC protocol, and including a bitmap indication of the search subset for the neighbor cell resource allocation in the protocol information element. Transmitting the neighbor cell configuration message at block 310 may include: a protocol message, which may include a protocol information element, neighbourCellConfiguration, is transmitted to UE 112 and other associated UEs, if they exist.

The resource allocations at different base stations, such as 106A-C, may not need to be of the same size. For example, the neighbor cell 104B may provide resource allocation for a single broadcast data traffic flow, while the serving base station 108 may provide resource allocation for multiple broadcast data traffic flows. Therefore, the resource allocation of the serving cell 102 has a larger size. In this exemplary scenario, an indicator of whether the allocations of all neighbor cells 104A-C are the same or different relative to the allocation of the serving cell 102 may result in allocations that are labeled as different. In such a scenario, the UE 112 may not be able to exclude any potential allocation areas as allocation areas for the neighbor cell 104B, except for those specifically designated areas that are not occupied by any resource allocations.

In one embodiment of the disclosure, an indicator may be sent to the UE 112 indicating whether the allocation of all neighbor cells 104A-C is a subset relative to the allocation of the serving cell 102, including the case where the allocation of neighbor cells 104A-C is the same as the allocation of the serving cell 102. Optionally, the indicator may also indicate that the allocation of all neighbor cells 104A-C is not a subset relative to the allocation of the serving cell 102. With such an indicator, one scenario may be that the UE 112 may advantageously receive signaling that the allocation of the neighbor cell 104B is a subset of the allocation of the serving cell 102 when the allocation of the neighbor cell 104B completely overlaps the allocation of the serving cell 102. In such a scenario, the UE 112 may advantageously be notified: the potential allocation area of the neighbor cell 104B is limited to an allocation area of at most the serving cell 102. In such a scenario, the UE 112 may perform measurements within any allocation region that does not overlap with the known allocation region of its serving cell 102. More details are in fig. 4 and related description.

Fig. 4 illustrates an example neighbor cell resource allocation map 400. The neighbor cell resource allocation map 400 may include a logical representation of the entire search space of neighbor cell resource allocations that are of interest from the perspective of the UE 102 for the purposes of channel measurement, as well as a logical representation of a search subset that only encompasses the neighbor cell resource allocation area. The neighbor cell resource allocation map 400 may include two areas, a shaded area 410 and a blank area 412. Region 410 may represent a neighbor cell resource allocation that overlaps with the allocation of serving cell 102, and this region may be excluded from a search by UE 112 for channel measurement purposes. As shown in fig. 4, the transmission frame allocation for the serving BS 108 of interest to the UE 102, e.g., MBSFN subframes, may completely overlap the allocation in the neighbor cell 1104A. The resource allocation of neighbor cell 2104B is shown as partially overlapping the allocation in serving cell 102. No MBSFN subframes are allocated in neighbor cell 3104C. Since the allocation for each of the neighbor cells 104A-C may potentially be a subset of the allocation in the serving cell 102, the UE 112 may advantageously be signaled that the allocation of the neighbor cells is a subset of the allocation in the serving cell 102, and the UE 112 may exclude the known allocation region 410 of the serving cell 102 from its measurements. When only signaled that the allocation of the neighbor cells 104A-C is different, the UE 112 may need to exclude the entire allocation spaces 410 and 412 from its measurements because the indication does not limit the possible locations of the allocation of the neighbor cells 104A-C. By being able to exclude only some regions from its measurements, the UE 112 may advantageously perform measurements more quickly, more accurately, with less power consumption on available reference signals for non-excluded regions.

Fig. 4 may illustrate a logical representation of resource allocation along only one axis. The axis may comprise time, frequency or code domain multiplexing, as is well known to those skilled in the art. It will further be appreciated that the dispensing region may also contain multiple axes. For example, Orthogonal Frequency Division Multiple Access (OFDMA) may have a time axis and a frequency axis, and OFDMA with orthogonal coding may have a time axis, a frequency axis, and a coding axis.

Fig. 5 illustrates an example method 500 for collecting measurements at the UE 112 based on a search subset of neighbor cell resource allocations. The method 500 may include: at block 504, neighbor cell resource configuration information is received from the serving cell 112, and at block 506, measurements are collected based on the search subset included in the neighbor cell resource configuration information. Receiving the neighbor cell resource allocation message at block 504 may include: a search subset for the neighbor cell resource configuration message is extracted. Collecting measurements at block 506 may include: one or more channel measurements are performed based on the searched subset of neighbor resource allocations.

Without any limitation to the scope, interpretation, and application of the claims set forth below, a technical effect of one or more of the example embodiments disclosed herein may be LTE node B and 3G or 4G mobile stations.

Embodiments of the present invention may be implemented in software, hardware, application logic or a combination of software, hardware and application logic. The software, application logic and/or hardware may reside in a memory, a processor, a computing device, or a wireless network node. If desired, portions of the software, application logic and/or hardware may reside in a computing device or network device, portions of the software, application logic and/or hardware may reside in other network devices, and portions of the software, application logic and/or hardware may reside in a computing device or network device. The application logic, software or an instruction set is preferably stored on any one of various common computer-readable media. In the context of this document, a "computer-readable medium" can be any medium or means that can contain, store, communicate, propagate, or transport the instructions for use by or in connection with the instruction execution system, apparatus, or device.

If desired, the different functions discussed herein may be performed in a different order and/or concurrently with each other. Furthermore, one or more of the above-described functions may be optional or may be combined, if desired.

Although various aspects of the invention are set out in the independent claims, other aspects of the invention comprise other combinations of features from the described embodiments, and/or dependent claims having features of the independent claims, and not solely the combinations explicitly set out in the claims.

It is also noted herein that while the above describes example embodiments of the invention, these descriptions should not be viewed in a limiting sense. On the contrary, many changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.

Claims (18)

1. A method for communication, comprising:

receiving, at a base station, an indication of a first resource allocation in each of one or more neighbor base stations; and

transmitting a message to at least one associated user equipment including a second indication indicating whether the first resource allocation of the one or more neighbor base stations is a subset of a second resource allocation of the base station.

2. The method of claim 1, wherein transmitting the message further comprises transmitting a neighbor cell configuration message including the second indication.

3. The method of claim 2, further comprising receiving the neighbor cell configuration message at the at least one associated user equipment.

4. The method of claim 3, further comprising performing one or more user equipment measurements based on the second indication.

5. The method of claim 1, wherein the second resource allocation is a multimedia broadcast single frequency network subframe allocation.

6. The method of claim 1, wherein the second indication comprises two bits that, when set to a binary value of 10, indicate that the first resource allocation of the one or more neighbor base stations is the same as or a subset of the second resource allocation in the base station.

7. The method of claim 1, wherein transmitting the message further comprises generating one of a first indicator to indicate that not all of the first resource allocations are a subset of the second resource allocations and a second indicator to indicate that each of the first resource allocations is a subset of the second resource allocations.

8. The method of any of claims 1-7, further comprising generating a neighbor cell resource allocation map that includes the first resource allocation and the second resource allocation to facilitate generating the second indication.

9. A method for communication, comprising:

receiving, at a user equipment, a message comprising an indication indicating whether a resource allocation of one or more neighbor base stations is a subset of a resource allocation of a serving base station; and

performing one or more channel measurements based on the indication.

10. The method of claim 9, wherein performing one or more channel measurements based on the indication comprises:

excluding resources indicated by the resource allocation of the base station from the channel measurements when the indication indicates that the resource allocation of the one or more neighbor base stations is a subset of the resource allocation of the base station.

11. An apparatus for communication, comprising:

a first module configured to receive, at a base station, an indication of a first resource allocation in each of one or more neighbor base stations; and

a second module configured to transmit a message to at least one user equipment including a second indication indicating whether the first resource allocation of the one or more neighbor base stations is a subset of a second resource allocation of the base station.

12. The apparatus of claim 11, wherein the user equipment is one of a third generation (3G) mobile station, a fourth generation (4G) mobile station, and a mobile computing device, or

Wherein the apparatus is one of a Long Term Evolution (LTE) node B (eNodeB), an LTE-Advance node B, and an access node compliant with a third Generation partnership project (3GPP) standard.

13. The apparatus of claim 11, wherein the second resource allocation is one of a regular multimedia broadcast single frequency network subframe allocation and a blank multimedia broadcast single frequency network subframe allocation.

14. The apparatus of any of claims 11-13, wherein the second module is further configured to generate one of a first indicator to indicate that not all of the first resource allocations are a subset of the second resource allocations and a second indicator to indicate that each of the first resource allocations are a subset of the second resource allocations.

15. An apparatus according to any of claims 11-13, wherein the second indication comprises two bits that, when set to a binary value of 10, indicate that the first resource allocation of the one or more neighbor base stations is the same as or a subset of the second resource allocation in the base station.

16. An apparatus for communication, comprising:

a first module configured to receive a message comprising an indication indicating whether a resource allocation of one or more neighbor base stations is a subset of a resource allocation of a serving base station; and

a second module configured to perform one or more channel measurements based on the indication.

17. The apparatus of claim 16, further comprising:

a third module configured to exclude resources indicated by the resource allocation of the base station from the one or more channel measurements when the indication indicates that the resource allocation of one or more neighbor base stations is a subset of the resource allocation of the base station.

18. The apparatus of any of claims 16-17, wherein the indication comprises two bits that, when set to a binary value of 10, indicate that a first resource allocation of the one or more neighbor base stations is the same as or a subset of a second resource allocation in the base station.