BRPI0715009A2

BRPI0715009A2 - Método de comunicação sem fio e aparato para atribuir células e blocos de recursos.

Info

Publication number: BRPI0715009A2
Application number: BRPI0715009-1A
Authority: BR
Inventors: Paul Marinier
Original assignee: Interdigital Tech Corp
Priority date: 2006-09-14
Filing date: 2007-09-11
Publication date: 2014-09-16
Also published as: MX2009002847A; KR20090075754A; EP2070374A2; WO2008033369A3; JP2010504026A; WO2008033369A2; TW200818943A; AR062850A1; AU2007294852A1; CA2664079A1; RU2009113821A; CN101518144A; US20080068981A1; WO2008033369A8; US8095139B2; KR20090068244A; IL197595A0

Description

Método de comunicação sem fio e aparato para atribuir células e blocos de

recursos.

CAMPO DE INVENÇÃO

A invenção está relacionada a sistemas de comunicação sem fio. Mais particularmente, a atribuição de recursos e celulares com sistemas de comunicação sem fio ortogonais uplink é divulgado.

HISTORICO

Acesso universal rádio terrestre Evolved (E-UTRA) está prevista a utilização de um regime de acesso múltiplo conhecido como single-rcarrier (SC) frequência Division Multiple Access (FDMA-SC)1 sobre a conexão. Com um tal sistema, os usuários conectados à mesma célula pode evitar interferência mútua completamente transmitindo em diferentes subcarriers e / ou diferentes timeslots, (ou transmissão calendário intervalos (TTIs)). Em uma típica forma de operar o sistema, um usuário poderia ser atribuído a um conjunto de subcarriers com base no longo prazo, e pode ser programado através de sinalização rápida em diferentes TTIs. A estação base controla a alocação de recursos para uma célula ou um conjunto de células. A estação base pode facilmente coordenar as transmissões de utilizadores ligados a essas células para evitar interferência mútua. No entanto, uma estação base não controlam diretamente as transmissões a partir de usuários conectados a outras células. Se estas transmissões a partir de outras células-usuários são recebidas em um nível muito elevado na base estação antenas, eles criam interferência. Assim, o desempenho na célula sofre.

A inter-célula interferência problema é particularmente significativo quando um usuário está situado numa localização dessas perdas que o seu caminho para dois (ou mais) células controladas por diferentes estações base são aproximadamente os mesmos. Esses usuários são freqüentemente referidos como "fronteira usuários."

Usuários Boundary criem uma mais aguda interferência inter-célula problema, porque o sinal recebido níveis são aproximadamente o mesmo entre as células que estão ligados a (servindo de células) e da célula (s) não estão 30 ligados à (ou seja, não servindo célula (s)). Portanto, a não servir célula, o sinal de um limite utilizador é susceptível de ser relativamente forte. Uma vez que o não serve célula não subcarriers e controlar o tempo de transmissão a partir da fronteira usuário, a probabilidade de colisão com outros usuários é elevado. Assim, para esses usuários, tanto mais retransmissões são necessários ou a modulação / codificação esquema deve 35 ser mais conservador, resultando na diminuição caudal.

A Figura 1 mostra uma abordagem convencional, que é usada para separar o conjunto de recursos que podem ser utilizadas em células adjacentes controladas por diferentes Node-Bs NBI, NB 2 e NB 3 em um celular multisistema de comunicação sem fio 100. O Node-Bs NBI1 NB 2 e NB 3 pode ser evoluído Node-Bs (eNodeBs). As letras A, B1 C e D1 mostrada na Figura 1 representam áreas de setores 105, 110 e 115, de diferentes células, onde blocos de recursos (por exemplo, subcarriers, timeslots, ortogonais códigos, etc), estão disponíveis para os utilizadores em 5 os respectivos sectores célula. Existem três setores tipicamente em uma célula, apenas uma das quais é apresentado na Figura 1 para cada Node-B NBI1 NB 2 e NB 3.

As shown in Figure 1, resource block B can only be used in the cell sector110 from NB2, resource block C can only be used in the cell sector 105 from NBI1 and resource block D can only be used in the cell sector 115 from NB3. The 10 arrows shown in Figure 1 point in the direction of the main Iobe of the antennas of the respectíve Node-Bs NBI1 NB2 and NB3. Users that transmit on different resource blocks do not interfere with each cífher ("orthogonal" transmissions). For example, if the resource blocks consist of different sets of frequencies, the users transmitting on these different sets of frequencies do not interfere with each other.

Typically1 a specific cell is first assigned to a user based on

path Ioss considerations. A block of resources available in a particular sector of the specific cell is then assigned to the user based on path Ioss considerations.

This prior art approach prevents interference from boundary users because two users that are Iocated within the inter-Node-B border area, but 20 connected to different Node-Bs, are using different resource blocks, and hence do not interfere with each other. However, this approach incurs a severe penalty in terms of overall spectrum efficiency, since certain blocks of resources cannot be reused in every cell. Furthermore1 this approach fails to exploit the intra-cell user orthogonality that is present with orthogonal FDMA (OFDMA) and SC-FDMA systems in particular, and does 25 not result in the highest possible capacity. Because1 as described above, certain resource blocks can only be used in specific cell sectors, the total number of users that can be served in the whole system for a given amount of resource blocks, (i.e., a given amount of spectrum), is Iess than what it could be if the resource blocks could be used in ali sectors (or more sectors). Thus, the capacity is not as high as it could be.

It would therefore be beneficiai if a resource and cell

assignment method and apparatus existed that was not subject to the Iimitations of the existing prior art.

SUMMARY

A method and apparatus for assigning cell and resource blocks to a wireless transmit/receive units (WTRU) in a wireless communicatíon system including a resource management unit and a plurality of cells having resource blocks are disclosed. The WTRU is currently associated with a particular one of the cells. Path Iosses between the WTRU and cells neighboring the particular cell are determined. The average Ievel of inter-cell interference on each resource block at each cell neighboring the particular cell is then determined. A signal-to-interference ratio (SIR) is then determined to support a guaranteed bit rate of the WTRU on an uplink. [0015] When signals from samecell users are orthogonal in the uplink, such as in E-UTRA1 (also known as Iong term

evolution (LTE)), signaling and procedures for assigning a set of resources and a cell to a user are provided in such a way that optimizes system capacity, taking into account intercell interference issues.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing summary, as well as the following detailed description, will be better understood when read with reference to the appended drawings, wherein:

Figure 1 shows a plurality of cells depicting a prior art segregation scheme to mitigate inter-cell interference;

Figure 2 shows a plurality of cells depicting an assignment of boundary users to a same Node-B allowing reuse of a block of resources in an extended cell;

Figure 3 shows a plurality of cells depicting interference leveis at nodes prior to assignment of resources; and

Figure 4 shows a wireless communication including a resource management unit, a plurality of Node-Bs and a WTRU.

DETAILED DESCRIPTION

Hereafter, a wireless transmit/receive unit (WTRU) includes but is not Iimited to a user equipment (UE)1 mobile station, fixed or mobile subscriber unit, pager, or any other type of device capable of operating in a wireless environment. When referred to hereafter, a base station includes but is not Iimited to a Node-B1 site controller, access point or any other type of interfacing device in a wireless environment.

In one embodiment, cell and resource block assignment decisions are jointly implemented to optimize capacity. The selection of the cell depends not only on the path Iosses to candidate cells, but also depends on other factors as will be explained below. Thus it is possible that the selected cell is not the one for which the path 30 Ioss is the smallest. A "candidate" cell is a cell to which a user may potentially connect. For example, the selection of a candidate cell may take place either during a handover procedure orfor initial access to a wireless communication system, (i.e., during initial cell selection), or during "cell reselection" during which the user is already connected to a cell in a "non-active" mode and connects to a new cell.

Figure 2 shows a multi-cell wireless communication system

200 comprising a plurality of adjacent cells 205, 210 and 215 controlled by different NodeBs NBI1 NB2 and NB3. Figure 2 depicts the assignment of boundary users to a common Node-B1 thus allowing reuse of a block of resources in an extended cell. Figure 2 provides an example of how making joint cell and resource assignment decisions can improve capacity.

For illustration purposes only, in Figure 2, the closest NodeB, (i.e., the Node-B that is at a minimum distance from the user), is also the one to which 5 the path Ioss is the smallest. In practice, the closest Node-B is not necessarily the same as the Node-B to which the path Ioss is the smallest (because of shadowing). However, to simplify the graphical representation, it is assumed that this is the case. In this example, the users Iocated within the border area between Node-Bs NBI and NB2 are ali connected to the same cell 210 and are assigned the same block of resources "B", regardless of 10 which cell is actually the closest to the users in terms of path loss. In Figure 2, the border of cell 210 is shown as extending into (i.e., penetrating) the border of cell 205. Thus1 ali of the users in the boundary area are assigned to the resource blocks "B". This presents the advantage that no user in cell 205 will generate significant interference on resource blocks "C". Thus1 it is now possible for some users in cell 210 to use resource blocks "C.

Depending on the specific system and/or procedure used,

this principie can be applied in methods used at the WTRU side, at the Node-B side or by a resource management unit as described in the paragraphs below. The decision of which cell (Node-B) a user should connect to depends not only on the path Iosses between this user and the different cells (as in prior art), but also on the leveis of interference measured on the different resource blocks at the different Node-Bs.

One possible selection criterion for the generalized cell and resource assignment provided for the uplink is to select the cell and resource block that minimizes the expected increase of inter-cell interference in dB among ali possible combinations of cell and resource block assignments, subject to constraints on the 25 maximum transmission power of the terminal and on the maximum Ievel of intercellinterference on a resource block and cell. The rationale for utilizing this criterion is that the interference on a given resource block at a given cell cannot exceed a certain Ievel if minimum, coverage and/or throughput requirements are to be met for the users utilizing this cell and resource block. Thus, the increase of interference (or average interference) 30 can be considered as a metric of capacity consumption that should be minimized for a given assignment.

Figure 3 shows a multi-cell wireless communication system 300 comprising a plurality of adjacent cells 305, 310 and 315 controlled by different NodeBs NBI, NB2 and NB3. Figure 3 shows an example of a scenario where a particular WTRU 320 needs to be assigned or re-assigned a cell and a resource block.

Referring to the example of Figure 3, the cells 305 and 310 are served by Node-Bs NBI and NB2. Cell 305 has a first set of candidate blocks of resources C and the cell 310 has a second set of candidate blocks of resources B that can potentially be assigned to the WTRU 320. A block of resources may refer to a set of subcarriers, (in a system using OFDMA or SG-FDMA), a set of timeslots, a set of orthogonal codes, (in a system using code division multiple access (CDMA)), or any combination thereof. In the example of Figure 3, it is assumed that before a block of 5 resources is assigned to the WTRU 320, and the Ievel of inter-cell interference is Iow at both Node-Bs NBI and NB2, except on resource block B at Node-B NB!, due to interference from another WTRU 325 that is connected to Node-B NB2. Block B is "associated" with NB2 in the sense that users connected to NB2 can transmit on block B, but the other Node-Bs experience inter-cell interference on block B due to these users 10 that are connected to NB2 and transmit on block B.

In this context, there are four (4) options for resource assignment of the WTRU 320, depending on which block of resources and which cell is assigned to the WTRU 320. Such resource assignment may be triggered during a handover procedure, a cell reselection procedure, a procedure to select the cell to 15 connect to for initial access, and the like. These options result in different outcomes in terms of the levei of inter- cell interference at Node-Bs NBI or NB2, as described in Tablel below. Table 1 depicts possible assignments and resulting changes in inter-cell interference, assuming that the user needs an average signal-to-interference ratio (SIR) of 8dB.

Assignment Required Expected change of inter-cell interference Tx Power 1 To NBl, block B 18 dBm Increase firom -100 dBm to -84 dBm at NB2, block B 2 ToNBl, block C 10 dBm Increase from -98 dBm to -91 dBm at NB2, block C 3 To NB2, block B IOdBm Increase from -90 dBm to -87 dBm at NB 1, block B 4 To NB2, block C 12 dBm Increase from -98 dBm to -88 dBm at NBl, block C Table 1

Assignment #3 minimizes the increase of inter-cell interference (in dB) and would therefore be selected according to the proposed criterion. Assignment #3 also corresponds to the approach of assigning the same Node-B and 25 resource block to boundary users, since the other WTRU is already connected to Node-B NB2 on block B. Thus, this assignment would realize the approach shown in Figure 2 that allows the eventual use of block C for users connected to the cell served by Node-B NB2.

The type of signaling required to support generalized cell/resource assignment depends on the architecture of the system and which node makes the allocation decision. Broadly speaking, two main possibilities can be envisioned. One is where the cell/resource assignment decision takes place in the network. The second is where the cell/resource assignment decision takes place in the terminal.

Figure 4 shows a wireless communication system 400 including a resource management unit 405, a plurality of Node-Bs NBI1 NB2 and NB3 and a WTRU 320. In the network-based case, the resource management unit 405 is designated for the WTRU 320 at the time of resource assignment. The node within which the resource management unit 405 is Iocated may be a specific base station that the WTRU previously contacted for initial access. Alternatively, as shown in Figure 4, the 5 node within which the resource management unit 405 is Iocated may be a central node to which the set of candidate Node-Bs NBI, NB2 and NB3 are connected. In the Iatter case, it should be understood that any measurement reported by the WTRU 320 to the resource management unit 405, as well as any command sent from the resource management unit 405 to the WTRU 320, may be relayed by the Node-B to which the terminal is temporarily 10 connected. Such measurement reporting may take place using any method known in the prior art.

As shown in Figure 4, the resource management unit 405 includes a processor 410, a transmitter 415 and a receiver 420. The WTRU 320 includes a processor 440, a transmitter 445 and a receiver 450. The processor 410 in the resource 15 management unit 405 is configured to estimate the amount of interference generated by the WTRU 320 for each candidate cell/resource assignment. To perform this estimation, the following Information is needed:

1) path Iosses between the WTRU 320 and cells that neighbor a cell within which the WTRU operates;

2) average Ievel of inter-cell interference on each resource block at each neighboring cell; and

3) required SIR to support a guaranteed bit rate.

Several possible methods exist for obtaining the set of path losses. First, the WTRU 320 may measure the received signal strength of a certain 25 beacon signal transmitted by each cell at a known transmission power on a known resource block, and report this signal strength, (or an average thereof), to the resource management unit 405. Another possibility is that the WTRU 320 transmits a probe signal on a certain reserved resource block at a specified transmissions power and that neighboring cells measure the received signal strength of this probe signal, (or an average 30 thereof). Neighboring cells then report the result of this measurement to the resource management unit 405.

The average Ievel of inter-cell interference must be measured by the candidate cells on each resource block. The Ievel of inter-cell interference measured at a particular cell (Node-B) depends on the resource block. For 35 instance, if a resource block is a set of frequencies, the interference varies from one set of frequencies to another. Such measurements can be assumed to take place on a continuous basis by the candidate cells. This Information may be relayed to the resource management unit 405 through the network infrastructure, either upon request or on a periodic basis. The required SIR to support a guaranteed bit rate can be estimated by the resource management unit 405 based on the guaranteed bit rate of the user on the uplink. This guaranteed bit rate may be known from prior negotiations between the WTRU 320 and the core network and/or the core network and the resource management unit 405. The degree of accuracy to which the required SIR needs to be known is not very high since this value does not affect the ranking between the cells/resource blocks. This value is used to determine whether the maximum transmission power of the WTRU 320 would be exceeded, or if the maximum Ievel of inter-cell interference on the candidate cell/resource block would be exceeded.

Based on the collected Information, the processor 410 in the resource management unit 405 can determine the expected increase of inter-cell interference on resource blocks at neighboring cells for each candidate cell and resource block assignment. The simplest way of making this calculation for each candidate assignment is as follows. First, estimate the required transmission power (TxPowef) of the WTRU 320 based on the required SIR, the average ievel of inter-cell interference on the candidate cell and resource block (Icand) and the path Ioss to the candidate cell (Lcand) based on the following formula:

TxPower (dBm) = SIR (dB) + Lcand (dB) + Icand (dBm). Equation (1)

Second, calculate the resulting Ievel of inter-cell interference (ΔΙί) generated by the user at each neighboring cell (i) and resource block (j) based on the required transmission power and the path Ioss between the WTRU 320 and the neighboring cell (Li):

Ali (dBm) = TxPower (dBm) - Li (dB). Equation (2)

Third, estimate the relative increase of inter-cell interference (IijVIij) on each resource block at each cell based on the pre-existing Ievel of inter-cell interference:

(IijVIij) (dB) = 10 IogIO [1 + Ali (mW) / Iy (mW)]. Equation (3)

The above calculation is only an example, and it is also possible to use more sophisticated methods to account for further interference increases due to power balancing effects after the user has started transmitting.

] After the processor 410 in the resource management unit 405 has estimated the set of estimated relative increases of inter-cell interference for each candidate cell and resource block assignment, an elected assignment is determined based on one of the following criteria:

1) smallest sum of estimated relative increases of inter-cell interference (in dB or in linear);

2) smallest maximum among the estimated relative increases of inter-cell interference; and

3) smallest weighted sum of estimated relative increases of inter-cell interference (in dB or in linear). The weights can be cell- and/or resource block-dependent if certain cells or resources are considered more important by the resource management unit 405.

Once the candidate assignment has been determined, the

resource management unit 405 may initiate a handover procedure to have the WTRU 320 connect to the elected cell in case this cell is different from the one it is currently connected to. The resource management unit 405 should be free to not execute such a handover procedure if the elected cell is not optimal for downlink transmission purposes 10 and if the uplink cell has to be the same as the downlink cell. In such a situation where the assignment is constrained to be within a certain cell or set of cells, the resource management unit 405 can elect the best assignment, (according to the chosen criterion), within this set of cells.

When instructing the WTRU 320 about the cell and resource block it should use, the resource management unit 405 may also specify a maximum bit rate or a maximum transmission power that the WTRU 320 can use, in order to Iimit the inter-cell interference the WTRU 320 generates.

In the terminal-based case, the entity making the decision about the assignment is in the processor 440 in the WTRU 320. The processor 440 in the WTRU 320 can make this decision according to the same criteria as in the network-based case (with similar calculations), but the Information that needs to be signaled is different.

The set of path Iosses between the WTRU 320 and the neighboring cells does not need to be signaled if the WTRU 320 makes the measurements itself, which is the most efficient solution. If the measurements were made by the base stations using the probe signal method described in the previous section, these measurements would need to be signaled to the WTRU 320.

The inter-cell interference leveis on each resource block and cell cannot be measured by the WTRU 320 and must be signaled. Several possibilities exist for this. First, the transmitter 445 in the WTRU 320 may send a request to the 30 resource management unit 405 in the network for the interference leveis of specified resource blocks at specified neighboring cells. Another possibiiity is that the neighboring cells períodically broadcast their average inter-cell interference leveis on each resource block. The receiver 450 in a WTRU 320 considering a connection to a certain cell would therefore Iisten for these broadcasted signals, such that the processor 440 may determine 35 inter-cell interference leveis. Optionally, the neighboring cells could also broadcast the maximum Ievel of average interference they can tolerate on each resource block, and/or the maximum increase of average interference they can tolerate on each resource block.

The required SIR to support the guaranteed bit rate of the WTRU 320 could be estimated autonomously by the processor 440 in the WTRU 320. Alternatively, the required SIR may be signaled by the resource management unit 405 to the receiver 450 of the WTRU 320 to minimize signaling overhead.

Once the processor 440 in the WTRU 320 has determined 5 the optimal cell and resource block assignment, (based on the same type of calculations as outlined above for the network-based case), several possibilities exist to execute the assignment. The first possibiiity is that the transmitter 445 of the WTRU 320 notifies the resource management unit 405 of its elected assignment. The resource management unit 405 then proceeds with a handover procedure as in the network-based case. The 10 resource management unit 405 may also deny the request from the WTRU 320 if for whatever reason the requested assignment is deemed not suitable. The resource management unit 405 may also accept the request under condition that the WTRU 320 does not transmit above a certain bit rate or transmission power similarly to the networkbased case.

The second possibiiity is that the WTRU 320 directly

contacts the elected cell on a special channel to request the use of the elected resource block. Upon receipt of the request, the cell could either accept (possibly conditionally as above) or deny the request and signal its response to the WTRU 320. This scenario is most suitable in the case where there is no central node that makes resource management decisions.

Embodiments

1. A method of assigning cell and resource blocks to a wireless transmit/receive unit (WTRU) in a wireless communication system including a resource management unit and a plurality of cells having resource blocks, the WTRU being currently associated with a particular one of the cells, the method comprising:

(a) determining the average Ievel of inter-cell interference generated by the WTRU at each neighboring cell and resource block; and

(b) determining a signal-to-interference ratio (SIR) required to support a guaranteed bit rate of the WTRU on an uplink.

2. The method of embodiment 1 further comprising:

(c) determining path Iosses between the WTRU and cells neighboring the particular cell.

3. The method of embodiment 2 wherein step (c) further comprises: the WTRU measuring the received signal strength of a certain beacon signal transmitted by each of the cells at a known transmission power on a known resource block; and the WTRU reporting the

received signal strength to the resource management unit.

4. The method of embodiment 2 wherein the WTRU reports an average received signal strength to the resource management unit.

5. The method as in any one of embodiments 2-4 wherein step (c) further comprises: the WTRU transmitting a probe signal on a certain reserved resource block at a specified transmission power;

6. The method of embodiment 5 wherein step (c) further comprises: the WTRU receiving measurements of the received signal strength of the probe signal.

7. The method as in any one of embodiments 1-6 wherein step (a) further comprises: measuring the average Ievel of inter-cell interference by candidate cells on each resource block.

8. The "method of embodiment 7 wherein the measurement of the average Ievel of intercell interference is performed upon request.

9. The method of embodiment 7 wherein the measurement of the average Ievel of intercell interference is performed on a periodic basis.

10. The method as in any one of embodiments 2-4 wherein step (b) further comprises: determining, based on the SIR, whether a maximum transmission power of the WTRU would be exceeded, or if a maximum Ievel of inter-cell interference on a candidate

cell/resource block would be exceeded.

11. The method as in any one of embodiments 1-10 further comprising: the resource management unit determining an expected increase of inter-cell interference on resource blocks at neighboring cells for each candidate assignment.

12. The method of embodiment 11 further comprising: estimating the required transmission power (TxPower) of the WTRU based on the required SIR, the average Ievel

of inter-cell interference on the candidate cell and resource block, Land, and the path Ioss to the candidate cell, Lcand, based on the following formula:

TxPower (dBm) = SIR (dB) + Lcand (dB) + lcand (dBm).

13. The method of embodiment 12 further comprising: calculate the resulting Ievel of intercell interference, ΔΝ, generated by the WTRU at each neighboring cell, i, and resource

block, j, based on the required transmission power and the path Ioss between the WTRU and the neighboring cell Li: Ati (dBm) = TxPower (dBm) - Li (dB).

14. The method of embodiment 13 further comprising: estimating the relative increase of inter-cell interference, lij'/ly, on each resource block at each cell based on the pre-existing

Ievel of inter-cell interference: IijVIij (dB) = 10 IogIO [1 + ΔΠ (mW) / Iij (mW)].

15. The method of embodiment 14 wherein after the resource management unit has estimated the set of estimated relative increases of inter-cell interference for each candidate cell and resource block assignment, an elected assignment is determined based on the smallest sum of estimated relative increases of inter-cell interference.

16. The method of embodiment 14 wherein after the resource management unit has estimated the set of estimated relative increases of inter-cell interference for each candidate cell and resource block assignment, an elected assignment is determined based on the smallest maximum among the estimated relative increases of inter-cell interference. 17. The method of embodiment 14 wherein after the resource management unit has estimated the set of estimated relative increases of inter-cell interference for each candidate cell and resource block assignment, an elected assignment is determined based on the smallest weighted sum of estimated relative increases of inter-cell interference.

18. A resource management unit for managing a plurality of cells and resource blocks, the resource management unit comprising:

(a) a receiver for receiving i) received signal strength measurements of a certain beacon cell transmitted by each of a plurality of cells at a known transmission Power on a known resource block, and ii) inter-cell interference measurements performed by- candidate cells on each resource block; and

(b) a processor for estimating a signal-to-interference ratio (SIR) required to support a guaranteed bit rate of the WTRU on an uplink.

19. The resource management unit of embodiment 18 wherein the WTRU reports an average received signal strength to the resource management unit.

20. The resource management unit of embodiment 18 wherein neighboring cells report measurements of the received signal strength to the resource management unit.

21. The resource management unit of embodiment 20 wherein the neighboring cells report an average received signal strength.

22. The resource management unit as in any one of embodiments 18-21 wherein the average Ievel of inter-cell interference by the candidate cells on each resource block is measured.

23. The resource management unit of embodiment 22 wherein the measurement of the average Ievel of inter-cell interference is performed upon request.

24. The resource management unit of embodiment 22 wherein the measurement of the average Ievel of inter-cell interference is performed on a periodic basis.

25. The resource management unit as in any one of embodiments 18-24 wherein the processor determines whether the maximum transmission power of the WTRU would be exceeded, or if the maximum Ievel of inter-cell interference on a candidate cell/resource block would be exceeded, based on the SIR estimate.

26. The resource management unit as in any one of embodiments 18-24 wherein the processor determines an expected increase of inter-cell interference on resource blocks at neighboring cells for each candidate assignment.

27. The resource management unit of embodiment 26 wherein the processor estimates the required transmission power (TxPower) of the WTRU based on the required SIR, the average Ievel of inter-cell interference on the candidate cell and resource block, lcand, and the path Ioss to the candidate cell, Lcand, based on the following formula: TxPower (dBm) = SIR (dB) + Lcand (dB) + lcand (dBm).

28. The resource management unit of embodiment 27 wherein the processor calculates the resulting Ievel of inter-cell interference, ΔΝ, generated by the WTRU at each neighboring cell, i, and resource block, j, based on the required transmission power and

the path Ioss between the WTRU and the neighboring cell, Li: ΔΠ (dBm) = TxPower (dBm) - Li (dB).

29. The resource management unit of embodiment 28 wherein the processor estimates the relative increase of inter-cell interference, IijVIjj1 on each resource block at each cell based on the pre-existing Ievel of inter-cell interference: IijVIij (dB) = 10 IogIO [1 + Ali

CmW) / Iy (mW)].

30. The resource management unit of embodiment 29 wherein after the resource management unit has estimated the set of estimated relative increases of inter-cell interference for each candidate assignment, the assignment being determined based on the smallest sum of estimated relative increases of inter-cell interference.

31. The resource management unit of embodiment 30 wherein after the resource management unit has estimated the set of estimated relative increases of inter-cell interference for each candidate cell and resource block assignment, an elected assignment is determined based on the smallest maximum among the estimated relative increases of inter-cell interference.

32. The resource management unit of embodiment 30 wherein after the resource management unit has estimated the set of estimated relative increases of inter-cell interference for each candidate cell and resource block assignment, an elected assignment is determined based on the smallest weighted sum of estimated relative increases of inter-cell interference.

33. A wireless transmit/receive unit (WTRU) comprising:

(a) a receiver configured to receive Information from a resource management unit about a particular cell and a resource block that the WTRU should use, path Iosses between the WTRU and cells that neighbor a cell that the WTRU operates within, and inter-cell interference leveis of specified resource blocks at specified neighboring cells; and 30 (b) a processor for estimating a signal-to-interference ratio (SIR) required to support a guaranteed bit rate of the WTRU on an uplink.

34. The WTRU of embodiment 33 wherein the WTRU reports an average received signal strength to the resource management unit.

35. The WTRU as in any one of embodiments 33 and 34 further comprising:

(c) a transmitter configured to request interference leveis of specified resource blocks at specified neighboring cells from a resource management unit.

36. The WTRU as in any one of embodiments 33-35 wherein the processor autonomously estimates the SIR needed to support the guaranteed bit rate. 37. The WTRU as in any one of embodiments 33-35 wherein the processor estimates the SIR needed to support the guaranteed bit rate based on the received Information.

38. The WTRU as in any one of embodiments 33-27 wherein the received Information further includes a maximum bit rate or a maximum transmission power that the WTRU

should use to Iimit inter-cell interference that the WTRU generates.

Although the features and elements are described in the embodiments in particular combinations, each feature or element can be used alone without the other features and elements of the preferred embodiments or in various combinations with or without other features and elements of the invention. The methods or 10 flow charts provided herein may be implemented in a Computer program, software, or firmware tangibly embodied in a computer-readable storage medium for execution by a general purpose Computer or a processor. Examples of computer-readable storage mediums include a read only memory (ROM), a random access memory (RAM), a register, cache memory, semiconductor memory devices, magnetic media such as 15 internai hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks, and digital versatile disks (DVDs).

Suitable processors include, by way of example, a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more micro processo rs in 20 association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) circuits, any other type of integrated circuit (IC), and/or a state machine.

A processor in association with software may be used to implement a radio frequency transceiver for use in a wireless transmit receive unit 25 (WTRU), user equipment (UE), terminal, base station, radio network controller (RNC), or any host Computer. The WTRU may be used in conjunction with modules, implemented in hardware and/or software, such as a camera, a video camera module, a videophone, a speakerphone, a vibration device, a speaker, a microphone, a television transceiver, a hands free headset, a keyboard, a Bluetooth® module, a frequency modulated (FM) radio 30 unit, a Iiquid crystal display (LCD) display unit, an organic light-emitting diode (OLED) display unit, a digital music player, a media player, a video game player module, an Internet browser, and/or any wireless local area network (WLAN) module.

Claims

1.Um método de alocação de blocos de células e de recursos para um celular transmissão / recepção unidade (WTRU) em um sistema de comunicação sem fio, incluindo uma unidade de gestão de recursos e de uma pluralidade de células com recurso, bloqueia o WTRU estar associados a um determinado momento uma das células, o método compreendendo: (a)determinar perdas caminho entre a WTRU e células vizinhas à célula especial; (b)determinar o nível médio de interferência inter-células, gerada pela célula vizinha WTRU em cada bloco e de recursos, e (c) determinar um sinal-interferência ratio (SIR), necessários para apoiar uma garantidos taxa de bits do WTRU sobre um uplink.

2. O método da reivindicação 1 onde passo (uma) ainda compreende: a WTRU medir o sinal recebido de um determinado pólo sinal transmitido por cada uma das células em uma conhecida transmissão poder de um recurso conhecido bloco, e os relatórios WTRU recebeu o sinal para a gestão dos recursos da unidade.

3. O método de crédito 2 onde o WTRU relatórios recebeu uma média do sinal para a gestão dos recursos da unidade.

4. O método da reivindicação 1 onde passo (uma) ainda compreende: a sonda WTRU transmitir um sinal sobre um determinado bloco recursos reservados a transmissão de um determinado poder.

5. O método de 4 alegação onde passo (uma) ainda compreende: as medições de WTRU recebendo o sinal recebido força de sinal da sonda.

6. O método da reivindicação 1 onde passo (b) mais compreende: medir o nível médio de inter-célula interferência por candidatos células em cada recurso bloco.

7. O método de reivindicação 6 em que a medição do nível médio de interferência inter-célula é realizado mediante solicitação.

8. O método de reivindicação 6 em que a medição do nível médio de interferência inter-célula é realizado numa base periódica.

9. O método da reivindicação 1 onde passo (c) ainda inclui: determinar, com base nas salvaguardas, se uma potência máxima de transmissão do WTRU seria ultrapassado, ou se um nível máximo de interferência inter-celular em um candidato células / recurso bloco seria ultrapassado.

10. O método da reivindicação 1 que inclui ainda: a unidade de gestão de recursos determina um aumento esperado de inter-célula interferência sobre recursos em blocos vizinhos células para cada candidato atribuição.

11.O método de reclamar outros 10 que inclui: estimar a potência necessária transmissão (TxPower) do WTRU baseada na necessária SIR1 o nível médio de inter-célula interferência sobre o candidato célula e bloquear recursos, lcand, eo caminho para a perda candidatos célula, Lcand, com base na seguinte fórmula: TxPower (dBm) = SIR (dB) + Lcand <dB) + lcand (dBm).

12. O método de reivindicação. 11 novas incluem:calcular o nível resultante da inter-célula interferências, ΔΝ, gerada pela WTRU em cada célula vizinha, i, e de recursos bloco,, j, com base na potência e transmissão exigido o caminho entre a perda WTRU e os vizinhos Li celular: ΔΝ (dBm) = TxPower (dBm) - Li (dB).

13. O método de reivindicação 12 novas compreendendo: a estimativa do aumento do peso relativo das inter-célula interferências, IijVIij1 em cada um dos recursos em cada bloco de células baseiam-se no pré-existente nível de interferência inter-celular: lY '/ lij (dB) = 10 loglO [1 + Δli (MW) /1 «(mW)].

14. O método de reivindicação 13 onde a gestão dos recursos após a unidade ter estimado o conjunto de aumentos relativos estimados de interferência inter-celular e celular para cada candidato recurso bloco cessão, eleito uma atribuição é determinada com base no menor valor estimado de aumentos relativos de inter - célula interferência.

15. O método de reivindicação 13 onde a gestão dos recursos após a unidade ter estimado o conjunto de aumentos relativos estimados de interferência inter-celular e celular para cada candidato recurso bloco cessão, eleito uma atribuição é determinada com base no menor máxima entre os estimados aumentos relativos de inter célula-interferência.

16. O método de reivindicação 13 onde a gestão dos recursos após a unidade ter estimado o conjunto de aumentos relativos estimados de interferência inter-celular e celular para cada candidato recurso bloco cessão, eleito uma atribuição é determinada com base no menor soma ponderada das estimativas de aumentos relativos de inter célula-interferência.

17. Uma unidade de gestão de recursos para gerir uma pluralidade de células e de recursos blocos, a unidade de gestão de recursos incluem: (a) um receptor para receber i) recebeu sinal medições de uma determinada célula baliza transmitida por cada um de uma pluralidade de células em uma conhecida transmissão poder de um recurso conhecido bloco, e ii) inter-celular interferência medições realizadas pelo candidato células em recurso cada bloco, e (b) um processador para calcular um sinal-interferência ratio (SIR), necessários para apoiar uma garantidos taxa de bits do WTRU sobre um uplink.

18. A gestão dos recursos da unidade de crédito em que os 17 relatórios WTRU recebeu uma média do sinal para a gestão dos recursos da unidade.

19. A gestão dos recursos da unidade de crédito em que 17 células vizinhas relatório medições do sinal recebido para a gestão dos recursos da unidade.

20.A gestão dos recursos da unidade de crédito 19 células vizinhas onde o relatório uma média do sinal recebido.

21. A gestão dos recursos da unidade de crédito 17 onde o nível médio de inter-célula interferência pelo candidato células em cada recurso bloco é medido.

22.A gestão dos recursos da unidade de reivindicação 21 onde a medição do nível médio de interferência inter-célula é realizado mediante solicitação.

23.A gestão dos recursos da unidade de reivindicação 21 onde a medição do nível médio de interferência inter-célula é realizado numa base periódica.

24.A gestão dos recursos da unidade de crédito 17 onde o processador determina se a potência máxima de transmissão do WTRU seria ultrapassado, ou se o nível máximo de interferência intercelular em um candidato células / recurso bloco seria ultrapassada, com base na estimativa SIR.

25.A gestão dos recursos da unidade de crédito 17 onde o processador determina um aumento esperado de inter-célula interferência sobre recursos em blocos vizinhos células para cada candidato atribuição.

26.A gestão dos recursos da unidade de crédito 25 onde o processador calcula a necessária transmissão de potência (TxPower) do WTRU baseada na necessária SIR, o nível médio de inter-célula interferência sobre o candidato célula e bloquear recursos, ICand> e perda para o caminho o candidato célula, Lcand, com base na seguinte fórmula: TxPower (dBm) = SIR (dB) + Lcand (dB) + lcand (dBm).

27.A gestão dos recursos da unidade de crédito 26 onde o processador calcula o nível resultante da inter-célula interferências, ΔΠ, gerada pela WTRU em cada célula vizinha, i, e de recursos bloco, j, com base na potência e transmissão exigido o caminho entre a perda o WTRU e as células vizinhas, Lr. ΔΠ (dBm) = TxPower (dBm) - U (dB).

28.A gestão dos recursos da unidade de crédito 27 onde o processador calcula o aumento do peso relativo das inter-célula interferências, IY '/ lij, sobre cada um dos recursos em cada bloco de células baseiam-se no pré-existente nível de interferência inter-celular: Iy 7 lij (dB) = 10 IogIO [1 + ΔΠ (MW) / IY (mW)].

29.A gestão dos recursos da unidade de reivindicação 28 onde a gestão dos recursos após a unidade ter estimado o conjunto de aumentos relativos estimados de interferência inter-célula para cada candidato tarefa, a tarefa a ser determinada com base na menor soma dos estimados aumentos relativos de interferência inter-celular.

30. A gestão dos recursos da unidade de reivindicação 29 onde a gestão dos recursos após a unidade ter estimado o conjunto de aumentos relativos estimados de interferência inter-celular e celular para cada candidato recurso bloco cessão, eleito uma atribuição é determinada com base no menor máxima entre os estimados aumentos relativos de inter-célula interferência.

31. A gestão dos recursos da unidade de reivindicação 29 onde a gestão dos recursos após a unidade ter estimado o conjunto de aumentos relativos estimados de interferência inter-celular e celular para cada candidato recurso bloco cessão, eleito uma atribuição é determinada com base no menor soma ponderada das estimativas de aumentos relativos de inter-célula interferência.

32. Um celular transmitir / receber unidade (WTRU) compreendendo: (a) um receptor configurado para receber informações de uma unidade de gestão de recursos sobre uma determinada célula e bloquear um recurso que deve utilizar o WTRU, o trajeto entre as perdas e WTRU células que uma célula que o vizinho WTRU opera dentro, e inter-célula interferência níveis de recurso especificado em blocos especificados células vizinhas, e (b) um processador para calcular um sinal-interferência ratio (SIR), necessários para apoiar uma garantidos taxa de bits do WTRU sobre um uplink.

33. A alegação WTRU de 32 relatórios onde o WTRU recebeu uma média do sinal para a gestão dos recursos da unidade.

34. A alegação WTRU de 32 novas compreendendo: (c) um transmissor configurado para pedir interferência níveis de recurso especificado no especificado blocos vizinhos células a partir de uma unidade de gestão de recursos.

35. A alegação WTRU de 32 em que o processador autonomamente estimativas do SIR necessários para apoiar a taxa de bits garantida.

36. A alegação WTRU de 32 em que o processador calcula o SIR necessários para apoiar a taxa de bits garantida baseada na informação recebida.

37. A alegação WTRU de 32 em que as informações recebidas ainda inclui um máximo de taxa de bits ou uma potência máxima de transmissão que o WTRU deve utilizar para limitar a interferência inter-célula WTRU que o gera.