WO2013131695A1

WO2013131695A1 - Support for neighbor cell interference property estimation

Info

Publication number: WO2013131695A1
Application number: PCT/EP2013/052145
Authority: WO
Inventors: Thomas Chapman; Hans Thomas Hoehne; Patrick Marsch; Krystian Pawlak
Original assignee: Nokia Siemens Networks Oy
Priority date: 2012-03-07
Filing date: 2013-02-04
Publication date: 2013-09-12

Abstract

There are provided measures for support for neighbor cell interference property estimation, particularly at interference-aware receivers. Such measures exemplarily comprise preparation of neighbor cell activity information indicative of transmission properties regarding at least one cell being a neighboring cell to a serving cell and signaling of the neighbor cell activity information on a downlink control or broadcast channel towards a terminal in the serving cell at a network side, and acquisition of the neighbor cell activity information on the basis of the signaling and estimation of a measure of neighbor cell interference properties on the basis of the acquired neighbor cell activity information at a terminal side.

Description

Support for neighbor cell interference property estimation Field

The present invention relates to support for neighbor cell interference property estimation. More specifically, the present invention exemplarily relates to measures (including methods, apparatuses and computer program products) for realizing support for neighbor cell interference property estimation, particularly at interference-aware receivers.

Background

The present specification generally relates to physical layer procedures in cellular communication systems and/or network deployments, such as UMTS, HSPA, LTE/LTE-A or the like. In such cellular communication systems and/or network deployments, suppression or at least mitigation of interference of neighboring cells in a serving cell is gaining more importance in view of various developments in the context of improvements of spectral efficiency or the like.

For facilitating any (e.g. inter-cell) techniques (e.g. for improving spectral efficiency or the like) which are liable to neighbor cell interference, interference-aware receivers are employed at receivers (at terminals) so as to improve the receive SINR. Such interference-aware receivers for example include type 2i/3i receivers also referred to as interference-aware (diversity) equalizers.

For such interference-aware receivers to work efficiently, these need to have an exact as possible knowledge of interfering signals such as a corresponding signature or covariance matrix and power of the interference in order to adjust the receive filter accordingly.

However, it is difficult to estimate neighbor cell interference at a receiver. A receiver could use an assumption on transmissions in neighbor cells (e.g . always transmitting, 50% probability of transmission etc.), which is however static and hardly in line with real life conditions at least at significant time periods. Otherwise, a receiver could also attempt to decode physical layer commands of neighbor cells on a downlink control channel, which contain scheduling information or the like, but this may not be successful due to the fact that these physical layer commands are typically subject to power control (e.g. if in a neighbor cell a UE is close to its serving base station, the physical layer commands will be transmitted at low power, so that an interfered receiver in a cell adjacent to an interfering neighboring cell will not be able to decode the physical layer commands, even though it may be strongly interfered by the corresponding data transmission, which is not subject to power control).

A receiver could further estimate neighbor cell interference by estimating a dominant interferer's channel or by estimating an actual covariance matrix. Both estimations would preferably have to be accomplished for each TTI, so the power estimate would apparently need to be updated at the same rate. While estimation of the actual covariance matrix typically provides for an exacter result closer to reality, it suffers from the fact that separating the own signal of a serving base station from the interference covariance takes some effort and degrades performance. The problem with the (neighbor cell interference) property estimate is indeed that the receiver can typically estimate the relative power difference of the wanted signal's pilot and the interfering signal's pilot, but estimating their share of the total power, and thus their actual power levels, is somewhat more complicated.

Therefore, there is a need to provide for support for neighbor cell interference property estimation, particularly at interference-aware receivers. Summary

Various exemplary embodiments of the present invention aim at addressing at least part of the above issues and/or problems and drawbacks.

Various aspects of exemplary embodiments of the present invention are set out in the appended claims.

According to a first exemplary aspect of the present invention, there is provided a method comprising acquiring neighbor cell activity information, said neighbor cell activity information being indicative of transmission properties regarding at least one cell being a neighboring cell to a serving cell on the basis of a signaling on a downlink control or a downlink grant channel or a broadcast channel from a network side, and estimating a measure of neighbor cell interference properties on the basis of the acquired neighbor cell activity information.

In a variant/modification of the first exemplary aspect of the present invention, it may be the case that

the acquiring comprises receiving the neighbor cell activity information in the signaling from a base station of the serving cell or a controller of the base station of the serving cell, and/or

the signaling comprises dedicated signaling on a downlink control channel or a downlink broadcast channel, and/or

the neighbor cell activity information comprises a measure of at least one of a load, a number of active terminals and a transmission power in the at least one neighboring cell .

the acquiring comprises receiving a command in the signaling from a base station of the serving cell or at least one base station of the at least one neighboring cell and decoding the neighbor cell activity information in the received command, and/or the signaling comprises dedicated signaling on a downlink control channel or a downlink grant channel from the at least one base station of the at least one neighboring cell or from the base station of the serving cell, and/or

the neighbor cell activity information comprises at least one of a measure of at least one of a load, a number of active terminals and a transmission power in the at least one neighboring cell, a presence/property information on a transmission in the at least one neighboring cell, a type information regarding a transmission in the at least one neighboring cell, and a precoding control information regarding a transmission in the at least one neighboring cell, or the neighbor cell activity information comprises an indication on the absence of a transmission schedule in the at least one neighboring cell for at least one transmission time interval . In the aforementioned variant/modification of the first exemplary aspect of the present invention, it may be the case that

the acquiring comprises listening to a downlink control channel or a downlink grant channel from the at least one base station of the at least one neighboring cell, and the neighbor cell activity information is decoded with a preconfigured neighbor cell activity transaction identifier of the at least one neighboring cell, or

the acquiring comprises listening to a downlink control channel or a downlink grant channel from the base station of the serving cell, and the neighbor cell activity information is decoded with a preconfigured neighbor cell activity transaction identifier and a preconfigured mapping between commands on the downlink broadcast channel and the at least one neighboring cell.

In the aforementioned variant/modification of the first exemplary aspect of the present invention, it may be the case that

the neighbor cell activity transaction identifier is preconfigured by a signaling from the base station of the serving cell or a controller of the base station of the serving cell, and/or the neighbor cell activity transaction identifier comprises one of a neighbor cell activity common transaction identifier or set thereof being for a plurality of terminals in the serving cell, a neighbor cell activity dedicated transaction identifier or set thereof for a single terminal in the serving cell, and a neighbor cell activity singular transaction identifier or set thereof for all terminals in the serving cell, and/or

the neighbor cell activity transaction identifier comprises a radio network transaction identifier of a high speed physical downlink shared channel, and/or

the downlink control channel comprises a high speed physical downlink shared control channel, and/or

the downlink grant channel comprises an absolute grant channel of an enhanced dedicated channel. In a variant/modification of the first exemplary aspect of the present invention, it may be the case that

the acquiring comprises receiving a signature structure in the signaling from at least one base station of the at least one neighboring cell and deducing the neighbor cell activity information from the received signature structure, and/or

the signaling comprises dedicated signaling on a downlink channel having a signature structure and slot numbering corresponding to those of a downlink relative grant channel from the at least one base station of the at least one neighboring cell, and/or

the neighbor cell activity information comprises at least one of a measure of at least one of a load, a number of active terminals and a transmission power in the at least one neighboring cell, a presence/property information on a transmission in the at least one neighboring cell, a type information regarding a transmission in the at least one neighboring cell, and a precoding control information regarding a transmission in the at least one neighboring cell.

In a variant/modification of the first exemplary aspect of the present invention, it may be the case that the acquiring comprises monitoring the signaling from a base station of the serving cell or at least one base station of the at least one neighboring cell and deriving the neighbor cell activity information from the monitored signaling, and/or

the signaling comprises dedicated signaling on a downlink control channel or a downlink grant channel from the at least one base station of the at least one neighboring cell or broadcast signaling on a downlink broadcast channel from the base station of the serving cell, and/or

the downlink grant channel comprises an absolute grant channel of an enhanced dedicated channel.

In a variant/modification of the first exemplary aspect of the present invention, it may be the case that estimating the measure of neighbor cell interference properties comprises

estimating a channel to the at least one neighboring cell, and estimating a measure of neighbor cell interference signature and/or covariance for the estimated channel to the at least one neighboring cell on the basis of the acquired neighbor cell activity information.

the method is operable at or by a terminal or user equipment or modem, and/or

the estimated measure of neighbor cell interference is usable by an interference-aware receiver or equalizer or diversity equalizer, and/or

the neighbor cell activity information is acquired for each transmission time interval .

According to a second exemplary aspect of the present invention, there is provided a method comprising preparing neighbor cell activity information indicative of transmission properties regarding at least one cell being a neighboring cell to a serving cell, and signaling the prepared neighbor cell activity information on a downlink control or a downlink grant channel or a broadcast channel towards a terminal in the serving cell.

In a variant/modification of the second exemplary aspect of the present invention, it may be the case that

the signaling comprises transmitting the neighbor cell activity information from a base station of the serving cell or a controller of the base station of the serving cell towards the terminal, and/or

the signaling comprises dedicated signaling on a downlink control channel or a downlink grant channel or a broadcast signaling on a downlink broadcast channel, and/or

the signaling comprises transmitting a command including the neighbor cell activity information from a base station of a serving cell or at least one base station of the at least one neighboring cell towards the terminal, and/or

the signaling comprises dedicated signaling on a downlink control channel or a downlink grant channel from the at least one base station of the at least one neighboring cell or from the base station of the serving cell, and/or

the neighbor cell activity information comprises at least one of a measure of at least one of a load, a number of active terminals and a transmission power in the at least one neighboring cell, a presence/property information on a transmission in the at least one neighboring cell, a type information regarding a transmission in the at least one neighboring cell, and a precoding control information regarding a transmission in the at least one neighboring cell, or the neighbor cell activity information comprises an indication on the absence of a transmission schedule in the at least one neighboring cell for at least one transmission time interval . In the aforementioned variant/modification of the second exemplary aspect of the present invention, it may be the case that

the terminal is preconfigured with a neighbor cell activity transaction or with a neighbor cell activity transaction identifier and a mapping between commands on the downlink broadcast channel and the at least one neighboring cell by a signaling from the base station of the serving cell or a controller of the base station of the serving cell, and/or

the neighbor cell activity transaction identifier comprises one of a neighbor cell activity common transaction identifier or set thereof being for a plurality of terminals in the serving cell, a neighbor cell activity dedicated transaction identifier or set thereof for the terminal in the serving cell, and a neighbor cell activity singular transaction identifier or set thereof for all terminals in the serving cell, and/or

In both aforementioned variants/modifications of the second exemplary aspect of the present invention, it may be the case that

the command is transmitted from the at least one base station of the at least one neighboring cell with constant power which is fixed or dependent on an assumed impact of the neighbor cell activity information on performance of an interference-aware receiver or equalizer or diversity equalizer at the terminal, and/or

the command is transmitted from the base station of the serving cell with flexible power controlled in accordance with a pathloss condition between the base station and the terminal. In a variant/modification of the second exemplary aspect of the present invention, it may be the case that

the signaling comprises transmitting a signature structure from at least one base station of the at least one neighboring cell towards the terminal, and/or

the method is operable at or by a network entity or modem, and/or the neighbor cell activity information is prepared and signaled for each transmission time interval.

According to a third exemplary aspect of the present invention, there is provided an apparatus comprising an interface configured to communicate with at least another apparatus, a memory configured to store computer program code, and a processor configured to cause the apparatus to perform : acquiring neighbor cell activity information, said neighbor cell activity information being indicative of transmission properties regarding at least one cell being a neighboring cell to a serving cell on the basis of a signaling on a downlink control or a downlink grant channel or a broadcast channel from a network side, and estimating a measure of neighbor cell interference properties on the basis of the acquired neighbor cell activity information. In a variant/modification of the third exemplary aspect of the present invention, it may be the case that

the processor is configured to cause the apparatus to perform receiving the neighbor cell activity information in the signaling from a base station of the serving cell or a controller of the base station of the serving cell, and/or

In a variant/modification of the third exemplary aspect of the present invention, it may be the case that

the processor is configured to cause the apparatus to perform receiving a command in the signaling from a base station of the serving cell or at least one base station of the at least one neighboring cell and decoding the neighbor cell activity information in the received command, and/or

the neighbor cell activity information comprises at least one of a measure of at least one of a load, a number of active terminals and a transmission power in the at least one neighboring cell, a presence/property information on a transmission in the at least one neighboring cell, a type information regarding a transmission in the at least one neighboring cell, and a precoding control information regarding a transmission in the at least one neighboring cell, or the neighbor cell activity information comprises an indication on the absence of a transmission schedule in the at least one neighboring cell for at least one transmission time interval . In the aforementioned variant/modification of the third exemplary aspect of the present invention, it may be the case that

the processor is configured to cause the apparatus to perform listening to a downlink control channel or a downlink grant channel from the at least one base station of the at least one neighboring cell, decoding the neighbor cell activity information with a preconfigured neighbor cell activity transaction identifier of the at least one neighboring cell, or

the processor is configured to cause the apparatus to perform listening to a downlink control channel or a downlink grant channel from the base station of the serving cell, decoding the neighbor cell activity information with a preconfigured neighbor cell activity transaction identifier and a preconfigured mapping between commands on the downlink broadcast channel and the at least one neighboring cell . In the aforementioned variant/modification of the third exemplary aspect of the present invention, it may be the case that

the neighbor cell activity transaction identifier is preconfigured by a signaling from the base station of the serving cell or a controller of the base station of the serving cell, and/or

the neighbor cell activity transaction identifier comprises one of a neighbor cell activity common transaction identifier or set thereof being for a plurality of terminals in the serving cell, a neighbor cell activity dedicated transaction identifier or set thereof for a single terminal in the serving cell, and a neighbor cell activity singular transaction identifier or set thereof for all terminals in the serving cell, and/or

the downlink grant channel comprises an absolute grant channel of an enhanced dedicated channel. In a variant/modification of the third exemplary aspect of the present invention, it may be the case that

the processor is configured to cause the apparatus to perform receiving a signature structure in the signaling from at least one base station of the at least one neighboring cell and deducing the neighbor cell activity information from the received signature structure, and/or

the processor is configured to cause the apparatus to perform monitoring the signaling from a base station of the serving cell or at least one base station of the at least one neighboring cell and deriving the neighbor cell activity information from the monitored signaling, and/or

the downlink grant channel comprises an absolute grant channel of an enhanced dedicated channel. In a variant/modification of the third exemplary aspect of the present invention, it may be the case that the processor is configured to cause the apparatus to perform :

the apparatus is operable as or at a terminal or user equipment or modem, and/or

the estimated measure of neighbor cell interference power is usable by an interference-aware receiver or equalizer or diversity equalizer, and/or the neighbor cell activity information is acquired for each transmission time interval .

According to a fourth exemplary aspect of the present invention, there is provided an apparatus comprising an interface configured to communicate with at least another apparatus, a memory configured to store computer program code, and a processor configured to cause the apparatus to perform : preparing neighbor cell activity information indicative of various transmission properties regarding at least one cell being a neighboring cell to a serving cell, and signaling the prepared neighbor cell activity information on a downlink control or a downlink grant channel or a broadcast channel towards a terminal in the serving cell.

In a variant/modification of the fourth exemplary aspect of the present invention, it may be the case that

the processor is configured to cause the apparatus to perform transmitting the neighbor cell activity information from a base station of the serving cell or a controller of the base station of the serving cell towards the terminal, and/or the signaling comprises dedicated signaling on a downlink control channel or a downlink grant channel or a broadcast signaling on a downlink broadcast channel, and/or

the processor is configured to cause the apparatus to perform transmitting a command including the neighbor cell activity information from a base station of a serving cell or at least one base station of the at least one neighboring cell towards the terminal, and/or

the neighbor cell activity information comprises at least one of a measure of at least one of a load, a number of active terminals and a transmission power in the at least one neighboring cell, a presence/property information on a transmission in the at least one neighboring cell, a type information regarding a transmission in the at least one neighboring cell, and a precoding control information regarding a transmission in the at least one neighboring cell, or the neighbor cell activity information comprises an indication on the absence of a transmission schedule in the at least one neighboring cell for at least one transmission time interval .

In the aforementioned variant/modification of the fourth exemplary aspect of the present invention, it may be the case that

the terminal is preconfigured with a neighbor cell activity transaction or with a neighbor cell activity transaction identifier and a mapping between commands on the downlink broadcast channel and the at least one neighboring cell by a signaling from the base station of the serving cell or a controller of the base station of the serving cell, and/or the neighbor cell activity transaction identifier comprises one of a neighbor cell activity common transaction identifier or set thereof being for a plurality of terminals in the serving cell, a neighbor cell activity dedicated transaction identifier or set thereof for the terminal in the serving cell, and a neighbor cell activity singular transaction identifier or set thereof for all terminals in the serving cell, and/or

the downlink grant channel comprises an absolute grant channel of an enhanced dedicated channel. In both aforementioned variants/modifications of the fourth exemplary aspect of the present invention, it may be the case that

the processor is configured to cause the apparatus to transmit the command from the at least one base station of the at least one neighboring cell with constant power which is fixed or dependent on an assumed impact of the neighbor cell activity information on performance of an interference- aware receiver or equalizer or diversity equalizer at the terminal, and/or the processor is configured to cause the apparatus to transmit the command from the base station of the serving cell with flexible power controlled in accordance with a pathloss condition between the base station and the terminal.

the processor is configured to cause the apparatus to perform transmitting a signature structure from at least one base station of the at least one neighboring cell towards the terminal, and/or

the apparatus is operable as or at a network entity or modem, and/or the neighbor cell activity information is prepared and signaled for each transmission time interval.

According to a fifth exemplary aspect of the present invention, there is provided a computer program product comprising computer-executable computer program code which, when the program is run on a computer (e.g . a computer of an apparatus according to the third exemplary aspect of the present invention), is configured to cause the computer to carry out the method according to the first exemplary aspect of the present invention.

According to a sixth exemplary aspect of the present invention, there is provided a computer program product comprising computer-executable computer program code which, when the program is run on a computer (e.g . a computer of an apparatus according to the fourth exemplary aspect of the present invention), is configured to cause the computer to carry out the method according to the second exemplary aspect of the present invention.

In a variant/modification of the fifth/sixth exemplary aspect of the present invention, it may be the case that the computer program product comprises or is embodied as a (tangible) computer-readable (storage) medium or the like on which the computer-executable computer program code is stored, and/or the program is directly loadable into an internal memory of the computer or a processor thereof. Advantageous further developments or modifications of the aforementioned exemplary aspects of the present invention are set out in the following.

Any one of the above aspects enables an efficient operation of interference- aware receivers, such as type 2i/3i receivers, at receivers (at terminals) (which may e.g . be operable in a serving cell) so as to improve the receive SINR by suppressing or at least mitigating interference of neighboring cells.

By way of exemplary embodiments of the present invention, there is provided support for neighbor cell interference property estimation, particularly at interference-aware receivers. More specifically, by way of exemplary embodiments of the present invention, there are provided measures and mechanisms for realizing support for neighbor cell interference property estimation, particularly at interference-aware receivers.

Thus, improvement is achieved by methods, apparatuses and computer program products enabling/realizing support for neighbor cell interference property estimation, particularly at interference-aware receivers. Brief description of the drawings

In the following, the present invention will be described in greater detail by way of non-limiting examples with reference to the accompanying drawings, in which

Figure 1 shows a schematic diagram of a procedure according to exemplary embodiments of the present invention, Figure 2 shows a schematic diagram of a first example of a system environment with signaling variants according to exemplary embodiments of the present invention, Figure 3 shows a schematic diagram of a second example of a system environment with signaling variants according to exemplary embodiments of the present invention,

Figure 4 shows a schematic diagram of signaling channels according to exemplary embodiments of the present invention,

Figure 5 shows a graph illustrating performance results of various approaches according to exemplary embodiments of the present invention, and

Figure 6 shows a schematic diagram of exemplary apparatuses according to exemplary embodiments of the present invention.

Detailed description of drawings and embodiments of the present invention

The present invention is described herein with reference to particular non- limiting examples and to what are presently considered to be conceivable embodiments of the present invention. A person skilled in the art will appreciate that the invention is by no means limited to these examples, and may be more broadly applied .

It is to be noted that the following description of the present invention and its embodiments mainly refers to specifications being used as non-limiting examples for certain exemplary network configurations and deployments. Namely, the present invention and its embodiments are mainly described in relation to 3GPP specifications being used as non-limiting examples for certain exemplary network configurations and deployments. In particular, a UMTS/HSPA communication system is used as a non-limiting example for the applicability of thus described exemplary embodiments. As such, the description of exemplary embodiments given herein specifically refers to terminology which is directly related thereto. Such terminology is only used in the context of the presented non-limiting examples, and does naturally not limit the invention in any way. Rather, any other network configuration or system deployment, etc. may also be utilized as long as compliant with the features described herein.

In particular, the present invention and its embodiments may be applicable in any cellular communication system and/or network deployment in which interference from neighboring cells has a certain impact on terminal/receiver performance. Particularly, applicability of the present invention and its embodiments is independent from application of inter-cell techniques and/or diversity-related techniques, but is generally given for any cellular network environment. For example, the present invention and its embodiments may be applicable in the context of any one of SISO, SIMO or MIMO modes, CoMP modes, and so on.

Hereinafter, various embodiments and implementations of the present invention and its aspects or embodiments are described using several variants and/or alternatives. It is generally noted that, according to certain needs and constraints, all of the described variants and/or alternatives may be provided alone or in any conceivable combination (also including combinations of individual features of the various variants and/or alternatives).

According to exemplary embodiments of the present invention, in general terms, there are provided measures and mechanisms for (enabling/realizing) support for neighbor cell interference property estimation, particularly at interference-aware receivers.

Figure 1 shows a schematic diagram of a procedure according to exemplary embodiments of the present invention. The exemplary procedure according to Figure 1 is assumed to take place at or between a terminal (or modem thereof) and a network element (or modem thereof). As shown in Figure 1, a procedure according to exemplary embodiments of the present invention comprises, at the side of the network element (NE), an operation of preparing neighbor cell activity information indicative of transmission properties regarding at least one cell being a neighboring cell to a serving cell, and an operation of signaling the prepared neighbor cell activity information on a downlink control or a downlink grant channel or a broadcast channel towards a terminal in the serving cell . Further, a procedure according to exemplary embodiments of the present invention comprises, at the side of the terminal (UE), an operation of acquiring the neighbor cell activity information, said neighbor cell activity information being indicative of transmission properties of the at least one cell being a neighboring cell to a serving cell on the basis of the signaling on a downlink control or a downlink grant channel or a broadcast channel from a network side, and an operation of estimating a measure of a neighbor cell interference properties on the basis of the acquired neighbor cell activity information (e.g . at an interference-aware receiver of/at the terminal).

According to exemplary embodiments of the present invention, the neighbor cell activity information (as prepared, signaled and acquired) are such that the thus indicated transmission properties relate to a potential interference (i.e. one or more interference properties) from the at least one neighboring cell in the serving cell . Accordingly, it could be said that such transmission properties may be indicative of a (potential) interference property or properties in the serving cell, which is caused by the at least one neighboring cell, i.e. the transmission therein.

As a potential interference from the at least one neighboring cell in the serving cell depends on a channel there-between, the estimation operation may also take into consideration the relevant channel . Namely, the estimation operation according to exemplary embodiments of the present invention may comprise estimating a channel (from the serving cell) to the at least one neighboring cell (which is potentially subject to inference from the at least one neighboring cell), and estimating a measure of at least one neighbor cell interference property (e.g. neighbor cell interference signature and/or covariance) for the estimated channel to the at least one neighboring cell on the basis of the acquired neighbor cell activity information.

Accordingly, transmission-related data regarding a neighboring cell, which is signaled to a terminal in a serving cell, contains information on the properties of the neighboring cell's transmissions (e.g. power, load, stream configurations, precoding, or the like). The terminal can then combine this transmission-related data with an estimate of the channel to the interferer in order to estimate its signature and/or covariance of the interference. Such process may take place for various interferers, neighboring cells, and/or channels, respectively.

According to exemplary embodiments of the present invention, the network element may be realized by or at different network entity of/in the underlying cellular communication system and/or network deployment. As evident from the below description, the preparation and signaling operations at the NE as well as the acquisition operation at the UE vary depending on the network entity representing the network element according to Figure 1. Generally, it is noted that a "neighbor cell" or a "neighboring cell" as referred to herein is not necessarily a cell being directly adjacent to a cell in question, i.e. a "serving cell" (in a geographical sense), but could also be (some cells) further away, as long as (potentially) posing interference to the serving cell . This can for example be the case if a base station is located on a hill and thus poses interference even to very distant cells.

Next, a first approach according to exemplary embodiments of the present invention is described . Figure 2 shows a schematic diagram of a first example of a system environment with signaling variants according to exemplary embodiments of the present invention. The thus illustrated system environment with signaling variants is applicable in the first approach according to exemplary embodiments of the present invention.

As shown in Figure 2, a serving cell indicated by a solid circle comprises a serving base station BS and a terminal UE, while an exemplary number of three neighboring base stations BS representing neighbor cells (not illustrated) are depicted. Further, a radio network controller (RNC) representing a controller of the base station of the serving cell is depicted. Typically, the RNC is aware of the load of NodeBs, e.g. by virtue of IuB flow control, or SIR target settings. In such scenario, it is assumed that transmit power from at least one of the neighbor cells causes interference in the serving cell, in particular for/at the terminal (especially, when residing at a cell edge of the serving cell adjacent to the at least one neighboring cell).

In the first approach according to exemplary embodiments of the present invention, the UE is informed about neighbor cell activities through signaling from the network element, which may be either the serving base station (e.g . the serving NodeB or eNodeB) or the controller of the serving base station (e.g . the RNC in case of the serving base station being a Node B).

Accordingly, the signaling comprises transmitting the neighbor cell activity information from a base station of the serving cell or a controller of the base station of the serving cell towards the terminal, and the acquiring comprises receiving the neighbor cell activity information in the signaling from a base station of the serving cell or a controller of the base station of the serving cell . Referring to Figure 1, such approach corresponds to the acquisition variant denoted as "receiving information". The neighbor cell activity information may comprise a measure of at least one of a load, a number of active terminals and a transmission power, e.g . an average load or transmission power, in the at least one neighboring cell, e.g. the strongest one/ones of the at least one neighboring cell. The signaling may comprise a dedicated signaling on a downlink control channel or a broadcast signaling on a downlink broadcast channel . When the controller (RNC) represents the network element according to Figure 1, the interference-relevant information available at the RNC may be sent e.g . by RRC signaling to the UE, e.g . on a downlink control channel such as HS- SCCH. Such signaling is indicated by a double-line arrow in Figure 2. When the serving base station represents the network element according to Figure 1, the interference-relevant information may be sent e.g . by NBAP signaling to the serving base station (e.g. eNodeB), and the serving base station (e.g . eNodeB) may compile the data and broadcast them in (an information element of a) SIB, e.g. on a downlink broadcast channel such as BCH . Such signaling is indicated by single-line arrows in Figure 2. Next, second to fifth approaches according to exemplary embodiments of the present invention are described .

Figure 3 shows a schematic diagram of a second example of a system environment with signaling variants according to exemplary embodiments of the present invention. The thus illustrated system environment with signaling variants is applicable in the second to fifth approaches according to exemplary embodiments of the present invention.

As the system environment of Figure 3 is basically equivalent to that of Figure 2, reference is made to the above description in connection with Figure 2. In addition to Figure 2, it is indicated which downlink channels may be usable for various approaches according to exemplary embodiments of the present invention in this regard . Namely, as described in detail below, at least one of a conventional HS-SCCH, a new/modified HS-SCCH (denoted by HS-SCCH'), a (potentially modified) E-AGCH, and a new or modified E- RGCH (denoted by E-RGCH') may be used.

In this regard, it may be noted that an E-AGCH is similar to a HS-SCCH, but with less information bits, and it is encoded in one block. Accordingly, one E-RNTI (used to mask the CRC in E-AGCH just like H-RNTI is used to mask the CRC in HS-SCCH) could be set aside for this purpose, and the meaning of the information bits may be redefined accordingly. In the second to fourth approaches according to exemplary embodiments of the present invention, the UE is informed about neighbor cell activities through signaling from the network element, which may be either at least one of the neighboring base stations of the neighbor cells or the serving base station (e.g. the serving NodeB or eNodeB). Accordingly, the second to fourth approaches according to exemplary embodiments of the present invention are essentially based on that all (relevant) cells transmit a special signaling with information on their own cell activity, which correspond to neighbor cell activity information at the serving cell receiving such signaling. The second and third approaches according to exemplary embodiments of the present invention are essentially based on signaling of a command including the neighbor cell activity information.

Accordingly, the signaling comprises transmitting a command including the neighbor cell activity information from a base station of a serving cell or at least one base station of the at least one neighboring cell towards the terminal, and the acquiring comprises receiving a command in the signaling from a base station of the serving cell or at least one base station of the at least one neighboring cell and decoding the neighbor cell activity information in the received command. Namely, the neighbor cell activity information is signaled in the command so that it may be decoded by (cell- edge) terminals in the serving cell. Referring to Figure 1, such approach corresponds to the acquisition variant denoted as "receiving & decoding information". The signaling may comprise a dedicated signaling on a downlink control channel or a downlink grant channel from the at least one base station of the at least one neighboring cell (as indicated by single-line arrows in Figure 3) or from the base station of the serving cell (as indicated by a double-line arrow in Figure 3). Further details in this regard are explained below. According to exemplary embodiments of the present invention, the neighbor cell activity information may be decoded with a preconfigured neighbor cell activity transaction identifier of the at least one neighboring cell .

According to exemplary embodiments of the present invention, when signaling is transmitted from the at least one base station of the at least one neighboring cell, the acquiring comprises listening to a downlink control channel (e.g. a HS-SCCH) or a downlink grant channel (e.g. an E-AGCH) from the at least one base station of the at least one neighboring cell, and the neighbor cell activity information is decoded with a preconfigured (or predefined) neighbor cell activity transaction identifier (e.g. a H-RNTI/E- RNTI for channels that carry CRC as HS-SCCH or E-AGCH; for E-RGCH, this would be decoded with a preconfigured (or predefined) special signature) of the at least one neighboring cell. When signaling is transmitted from the serving base station, the acquiring comprises listening to a downlink control channel (e.g. a HS-SCCH) or a downlink grant channel (e.g. an E-AGCH) from the base station of the serving cell, and the neighbor cell activity information is decoded with a preconfigured (or predefined) neighbor cell activity transaction identifier (e.g . a H-RNTI/E-RNTI for channels that carry CRC as HS-SCCH or E-AGCH; for E-RGCH, this would be decoded with a preconfigured (or predefined) special signature) and a preconfigured (or predefined) mapping between commands on the downlink broadcast channel and the at least one neighboring cell.

In case of signaling from the serving base station, which is particularly applicable when using a baseband hotel (i.e. a centralized system module capable of controlling multiple base stations (e.g . in a CoMP environment), if scheduling is known among neighboring cells, the neighbor cell activity information can be transmitted e.g. by HS-SCCH orders (or codes) in the serving cell. Then, the UE needs to know besides a neighbor cell activity transaction identifier (e.g. a H-RNTI) also which neighbor cell activity transaction identifier (e.g . a H-RNTI) corresponds to which neighbor cell (which mapping could have been previously clear by listening on a certain scrambling). As indicated above, while the above H-RNTI based technique is specifically usable for HS-SCCH based signaling, corresponding effects would be achieved by mapping and configuring of signatures" in case of an E-RGCH based signaling, and/or respective techniques for other conceivable signaling channels.

According to exemplary embodiments of the present invention, when being transmitted from the at least one base station of the at least one neighboring cell, the command in the second approach may be transmitted with constant power which is fixed or dependent on an assumed impact of the neighbor cell activity information on performance of an interference- aware receiver or equalizer or diversity equalizer at the terminal . When being transmitted from the base station of the serving cell, the command in the second approach may be transmitted with flexible power controlled in accordance with a pathloss condition between the base station and the terminal .

Namely, in the second approach according to exemplary embodiments of the present invention (in particular, when using HS-SCCH orders from neighboring cells), (physical layer) commands are not subject to power control so as to enable receipt thereof in an adjacent (serving) cell . Accordingly, the commands are transmitted with constant power and are not necessarily adjusted to the receive strength of the UEs in the own (neighboring) cell, while the information carried in the commands may be given different amount of power according to the importance or impact on performance of an interference-aware receiver such as a type 3i receiver.

In the second approach according to exemplary embodiments of the present invention, the neighbor cell activity information may comprise a measure of at least one of a load, a number of active terminals and a transmission power, e.g. an average load or transmission power, in the at least one neighboring cell (e.g . the strongest one/ones thereof). Additionally or alternatively, the neighbor cell activity information may comprise a presence/ property information on a transmission in the at least one neighboring cell (e.g . the strongest one/ones thereof), i.e. an information that a transmission is taking place or not, and potentially how long the transmission will take place or how long a low transmission power period will last (e.g . relating to a transmission in a HS-PDSCH). Additionally or alternatively, the neighbor cell activity information may comprise a type information regarding a transmission in the at least one neighboring cell (e.g . the strongest one/ones thereof), e.g . the type of transmission (such as MIMO ss/ds or non-MIMO). Additionally or alternatively, the neighbor cell activity information may comprise precoding control information regarding a transmission in the at least one neighboring cell (e.g . the strongest one/ones thereof), e.g . the used PCI in a MIMO ss transmission.

By decoding such information, a (cell-edge) UE may properly adjust its receive filter/strategy accordingly.

In the third approach according to exemplary embodiments of the present invention, the neighbor cell activity information comprises an indication on the absence of a transmission schedule in the at least one neighboring cell (e.g . the strongest one/ones thereof) for at least one transmission time interval (TTI). Such neighbor cell activity information, which may be transmitted from a neighboring base station when it does not schedule any transmission in a certain TTI, may indicate such lack of schedule in/for every TTI or on planned scheduling for multiple subsequent TTIs. By decoding such information, a (cell-edge) UE will know that no data transmission is taking place from a specific neighbor cell, and may properly adjust its receive filter/strategy accordingly.

In the second and third approaches according to exemplary embodiments of the present invention, the downlink control channel may for example be a HS-SCCH (of conventional or new/modified type), and the downlink grant channel may for example be an E-AGCH. While the E-AGCH is similar to the HS-SCCH, it is more efficient in terms of power consumption, which is due to more efficient encoding and smaller payload size. In the following, usage of a HS-SCCH as the downlink control channel for signaling in the second and third approaches according to exemplary embodiments of the present invention is exemplarily assumed for explanatory purposes. It is noted that similar features as described below with respect to the HS-SSCH are equally applicable with any other conceivable downlink channels when used in exemplary embodiments of the present invention. For the signaling on the HS-SCCH, so-called HS-SCCH orders (or codes) may be used as the (physical layer) commands carrying the neighbor cell activity information according to exemplary embodiments of the present invention. For example, when a plurality of pieces of neighbor cell activity information is signaled in the second approach described above, each information piece may be signaled in one order (or code) out of a set of HS- SCCHs or orders (or codes) thereof.

In the following, specific considerations regarding a neighbor cell activity transaction identifier (e.g . a H-RNTI) in the second and third approaches according to exemplary embodiments of the present invention are set out.

It is noted that HS-SCCH orders are encoded (masked) with an identifier, typically a H-RNTI, and thus has to be decoded (de-masked) with this identifier upon receipt. The purpose of such encoding (masking) is to address specific UEs, which may own the H-RNTI. Generally, it is distinguished between a "dedicated H-RNTI" and a "common H-RNTI".

The purpose of the common H-RNTI is to allow UEs to receive the HS-DSCH also in CELL_FACH state or in IDLE->CELL_FACH state transition, where it has not yet received a dedicated H-RNTI. A common H-RNTI is common to a set of UEs (but not all), and is calculated according to a specific formula . In order to obtain a common H-RNTI, the UE needs to read system information blocks (SIB) on a broadcast channel in its own cell. A dedicated H-RNTI is unique to a UE, and is configured by the network with direct signaling to the UE. It is used in a CELL_DCH state.

For the purpose of the second and third approaches according to exemplary embodiments of the present invention, an UE needs to know what is the relevant channel (e.g. the neighbor cell activity HS-SCCH) of the neighbor cell/cells, and hence what is the H-RNTI, i.e. the neighbor cell activity transaction identifier, of the neighbor cell/cells. This can be communicated by adding a new piece of information in the UE' s own cell's BCH channel telling the UEs on which H-RNTI they should listen for neighbor cell activity information of neighbor cells. Such approach might work without the RNC, however only if there is only one identical common neighbor cell activity H- RNTI for all base stations (i.e. NodeBs) in the network. Otherwise, the RNC would need to assemble a NodeB's neighbors' H-RNTIs. Alternatively, the relevant UEs can be configured at a later point in time, and could be also configured by the RNC e.g . by RRC signaling .

According to exemplary embodiments of the present invention, a neighbor cell activity transaction identifier or H-RNTI may be a common (set of) H- RNTI or as a dedicated (set of) H-RNTI.

A dedicated H-RNTI (for a single UE in the serving cell,) may be more in line with the current specifications, as indirect or explicit coordination of a NodeB's neighbor cell activity H-RNTIs is required, and thus no specific formula can be used . On the other hand, the neighbor cell activity H-RNTI is a good candidate to be made known in a SIB, similar to common H-RNTIs, and it may thus be a common H-RNTI (for a plurality of UEs in the serving cell). Also, the new cell-activity H-RNTI could in actual fact be a H-RNTI common to all UEs (in the serving cell).

When neighbor cell activity information is signaled from neighboring cells and when defining a new (set of) common H-RNTI as a neighbor cell activity transaction identifier according to exemplary embodiments of the present invention, at least the following definitions are applicable for current 3GPP specifications.

As regards physical layer procedures (FDD), as specified in 3GPP TS 25.214, the following may be defined for the UE procedure for receiving HS-DSCH and HS-SCCH in the CELL_DCH state.

Not only shall the UE monitor the HS-SCCHs of the configured HS- SCCH set with the dedicated H-RNTI, if the UE is configured with a dedicated H-RNTI. It shall also further monitor the HS-SCCH set with a neighbor cell activity (cell-activity) common H-RNTI of neighboring cells on the same frequency. If the UE is not configured with a dedicated H-RNTI, the UE shall monitor the HS-SCCHs of the configured HS-SCCH set with the common H-RNTI as defined in."

Generally, the maximum number of HS-SCCH orders simultaneously received by the UE across the serving HS-DSCH cell and all the activated secondary serving HS-DSCH cells is 2. For UEs supporting neighbor cell activity (cell-activity) decoding the number is increased by the amount of monitored neighboring cells.

The UE can be configured to simultaneously monitor a maximum of 1 HS-SCCH in one non-serving cell . This HS-SCCH is only used for HS-SCCH orders that indicate HS-DSCH serving cell change. For UEs supporting neighbor cell activity (cell-activity) decoding the number is increased by the amount of monitored neighboring cells"

It is noted that the set of strongest neighbor cells can be either configured by RRC, or can be assumed to be identical with the active set, or can be left to UE implementation. It can be left to UE implementation, if the HS-SCCH broadcast channel is the same among all cells in the network, only separated by scrambling . As regards Radio Resource Control (RRC) Protocol specification, as specified in 3GPP TS 25.331, the following may be defined for common H-RNTI selection (FDD and 1.28 Mcps TDD only). When the IE "Common H-RNTI Information" or the like is included in

System Information Block type 5 or System Information Block type 5bis or the like, the UE shall select the Common H-RNTI according to the following rules:

- compile a list of candidate Common H-RNTI IE(s) "Common H- RNTI" in the order of appearance in System Information Block type 5 or

System Information Block type 5bis or the like;

- select a Common H-RNTI from the list of candidate Common H- RNTIs based on U-RNTI as follows: "Index of selected Common H-RNTI" = U-RNTI mod K, where K is equal to the number of candidate Common H- RNTIs.

The purpose of the common H-RNTI is to allow UEs to receive the HS- DSCH also in CELL_FACH state where it has not yet received a dedicated H- RNTI. The above procedure by virtue of using a modulo operation will create random sets of UEs using one common H-RNTI. It is noted that, that when transitioning from IDLE to CELL_FACH state, a slightly different formula is used. It is noted that the common H-RNTI may range from 0.. K-1, and hence the dedicated H-RNTIs may be taking values of K and higher. When introducing a neighbor cell activity (cell-activity) common H-RNTI, it may take the value K, and the dedicated H-RNTIs may take values greater than K. If the amount of HS-SCCH codes in an H-RNTI set is limited, more neighbor cell activity (cell-activity) H-RNTIs could be reserved

When an IE "neighbor cell activity (cell-activity) Common H-RNTI Information" or the like is included in System Information Block type 5 or System Information Block type 5bis or the like, the UE shall compile a list of neighbor cell activity (cell-activity) Common H-RNTI IE(s) "Common H- RNTI" in the order of appearance in System Information Block type 5 or System Information Block type 5bis or the like. The UE shall set the CFN in relation to the SFN of the current cell .

As regards power control, as specified in various 3GPP TSs, it may be defined that the HS-SCCH power will be adapted to the actual needed SINR at the UE, and that the neighbor cell activity (cell-activity) HS-SCCH shall not be power controlled (at least, when being transmitted from the neighboring cell or cells). The fourth approach according to exemplary embodiments of the present invention is essentially based on signaling of a signature structure indicative of the neighbor cell activity information.

Accordingly, the signaling comprises transmitting a signature structure in the signaling from at least one base station of the at least one neighboring cell, and the acquiring comprises receiving a signature structure in the signaling from at least one base station of the at least one neighboring cell and deducing the neighbor cell activity information from the received signature structure. Namely, the neighbor cell activity information is signaled by virtue of the signature structure so that it may be deduced by (cell-edge) terminals in the serving cell . Referring to Figure 1, such approach corresponds to the acquisition variant denoted as "receiving signature & deducing". The signaling may comprise a dedicated signaling on a downlink channel having a signature structure and slot numbering corresponding to those of a downlink relative grant channel (e.g. an E- RGCH) from the at least one base station of the at least one neighboring cell.

Similar to the second approach described above, the neighbor cell activity information may comprise one or more of a measure of at least one of a load, a number of active terminals and a transmission power in the at least one neighboring cell, a presence/property information on a transmission in the at least one neighboring cell, a type information regarding a transmission in the at least one neighboring cell, and a precoding control information regarding a transmission in the at least one neighboring cell .

Figure 4 shows a schematic diagram of signaling channels according to exemplary embodiments of the present invention. The thus illustrated signaling channels and their mutual relationship are explanatory for the fourth approach according to exemplary embodiments of the present invention, namely using a non-serving (neighbor) cell E-RGCH type of a channel which uses a signature sequence to convey a (ternary) bit to the receivers in the serving cell .

Such fourth approach using a modified non-serving (neighbor) cell E-RGCH is currently deemed to be specifically efficient in terms of power consumption.

As a background, it is noted that the non-serving cell E-RGCH is used with the uplink E-DCH channel, where the serving cell is in control of the uplink data rates. The non-serving cell is provided with means to signal a 'DOWN' command to the UE(s) using an E-RGCH, if it suffers from too high interference from these UEs. The non-serving cell E-RGCH information is provided in the radio link addition phase, and the information may be common to multiple UEs, or it can be UE specific.

The E-RGCH channel structure is such that it uses a single SF128 code channel, but on top of it there are 40 orthogonal signatures, and to one UE, one signature serves as relative grant and one as HARQ ACK/NACK. Other signatures can be allocated to other UEs.

For the purposes of providing neighbor cell activity information according to exemplary embodiments of the present invention, in order to aid type 3i receivers or the like at UEs in the serving cell, a modified channel is introduced on the basis of the E-RGCH, which follows a different frame timing but the same slot timing as the E-RGCH, as evident from Figure 4. With a change in the signature pattern hopping (phase) the same SF128 code channel can be shared with the E-RGCH and the thus modified channel so that the UE needs to monitor just one code channel from the neighbor cells. With respect to Figure 4, the following is noted.

The HS-SCCH is used to schedule a data packet on HS-PDSCH(s) to a user served by this serving cell. The HS-PDSCH(s) follow two slots after the HS- SCCH used to indicate its presence. The HS-PDSCH(s) generate the interference the UE in the neighbor cell wants to cancel. The new E-RGCH based channel is used to convey indication of neighbor cell activity information, e.g . (at least) the presence or absence of the HS-PDSCH(s), i.e. corresponding transmissions, starting 2 slots later, as it is beneficial for the indication to be received earlier than the interfering channel, but it cannot take place any earlier than when the interfering channels are actually scheduled with HS-SCCH.

The new channel uses the orthogonal signatures defined for E-RGCH and E- HICH. The E-RGCH channel is the non-serving cell E-RGCH channel that is used to provide uplink scheduling related information to UEs served by a neighbor cell. The numbers in the slots represent a slot index as is used in the signature hopping pattern.

The new channel may use the same signature structure as the E-RGCH. This way the new channel and the E-RGCH can share the same spreading code and use a different signature. For this purpose, the hopping patterns of the two channels are in the same phase even though the channel timings are offset by 2 slots. Similarly, the new channel may use HS-SCCH timing and spreading code, but with power-efficient E-RGCH signatures.

Accordingly, there are various variants available for implementation of exemplary embodiments of the present invention, as described herein. The applicability of a certain one of such variants may be decided (in a tradeoff) on a case-by-case basis depending on specific conditions and/or requirements. For example, usage of the E-RGCH may be preferable from a power perspective (and can have effectively the same timing as the HS- SCCH), while usage of the HS-SCCH may be preferable from a code-space/ code-usage perspective.

Next, a fifth approach according to exemplary embodiments of the present invention is described .

For the fifth approach, the system environment with signaling variants according to exemplary embodiments of the present invention, as exemplarily illustrated in Figure 3, are equally applicable as well .

In the fifth approach according to exemplary embodiments of the present invention, the UE is enabled to derive information about neighbor cell activities through signaling from the network element. Accordingly, the fifth approach according to exemplary embodiments of the present invention is essentially based on that all (relevant) cells transmit a special signaling, which may but does not have to contain information on their own cell activity, which correspond to neighbor cell activity information at the serving cell receiving such signaling.

Accordingly, the signaling comprises transmitting some signaling from a base station of the serving cell or at least one base station of the at least one neighboring cell towards the terminal, and the acquiring comprises monitoring the signaling from a base station of the serving cell or at least one base station of the at least one neighboring cell and deriving the neighbor cell activity information from the monitored signaling . Referring to Figure 1, such approach corresponds to the acquisition variant denoted as "monitoring & deriving information". The signaling may comprise a dedicated signaling on a downlink control channel or a downlink grant channel from the at least one base station of the at least one neighboring cell (as indicated by single-line arrows in Figure 3) or from the base station of the serving cell (as indicated by a double-line arrow in Figure 3). In the fifth approach, the UE may be informed by higher layers about HS- SCCH codes used in neighboring cells, so that HS-SCCH activity can be monitored by the UE itself without decoding it (as in the second and third approaches described above). Namely, in the fifth approach, a signaling (not necessarily containing the neighbor cell activity information as contents) is utilized for deriving information on neighbor cell activity.

For further details, specifically relating to usable channels and properties thereof, reference is made to the above.

In the following, a description regarding simulation results in terms of receiver performance under different receiver assumptions is given.

Generally, simulation has shown that the degradation of type 3i receiver performance associated with a lack of knowledge of precoding information applied in adjacent cells is rather minimal, but a significant degradation is visible if a UE lacks knowledge on the presence or absence of transmissions are in neighboring cells. Figure 5 shows a graph illustrating performance results of various approaches according to exemplary embodiments of the present invention.

Specifically, Figure 5 shows achievable throughput distributions for different system loads (full buffer is assumed, but the average number of terminals per cell is changed), and for different receiver strategies. In Figure 5, the first to third approaches are compared with a baseline assumption.

The baseline assumption represents a conventional case without any signaling of neighbor cell activity information according to exemplary embodiments of the present invention. In such case, terminals always assume that adjacent base stations are transmitting at full power. This baseline case is depicted with a dashed line in Figure 5. A performance characteristic for the first approach ("Approach I") according to exemplary embodiments of the present invention is depicted with a solid line in Figure 5, wherein signaling of average load of neighboring cells is assumed. A performance characteristic for the second and third approaches ("Approach II", "Approach III") according to exemplary embodiments of the present invention is depicted with a bold and solid line in Figure 5, wherein signaling of TTI-wise information about whether or not transmissions are taking place in neighboring cells is assumed .

As evident from Figure 5, there is hardly any gain from approach I, but approaches II and III may deliver gains on the order of 2-4% median rate improvements for moderate to high loads. For low loads, also approach I shows gains. For very low loads (e.g. in a case where there is only one terminal receiving a transmission in a large set of cells), all approaches I to III equally provide around 4% median rate improvement. It is noted that the thus illustrated simulation results are based on the assumption of full buffer traffic, while the gains from approaches II and III are expected to be larger when bursty traffic is assumed .

This is effective, as the problem of interfering BS activity (or instantaneous Tx Power) is getting more significant in case of bursty traffic while Tx power may change from TTI to TTI rapidly from 25-30% during "silence" period when only basic control channels are broadcasted to 100% during HS- PDSCH transmission. Accordingly, exemplary embodiments of the present invention enable TTI-wise provision of neighbor cell activity information by way of a signaling concept.

In view of theses simulation results exhibiting a load dependency of the performance gain for the individual approaches, exemplary embodiments of the present invention may also encompass a selection of an (appropriate) approach based on the current (actual or average) load in each neighboring cell or all neighboring cells. Such selection may be applied at the base station of each cell representing a neighbor cell in the context of the preparation and/or signaling of neighbor cell activity information. According to exemplary embodiments of the present invention, support for neighbor cell interference property estimation, particularly at interference- aware receivers, may be realized. Thereby, an efficient operation of interference-aware receivers, such as type 2i/3i receivers, at receivers (at terminals) operable in the serving cell so as to improve the receive SINR by suppressing or at least mitigating interference of neighboring cells is enabled.

Specifically, it is enabled that interference-aware receivers have an exact as possible knowledge of interfering signals in order to adjust the receive filter accordingly, thereby ensuring their efficient operation. It is particularly enabled that a UE knows whether in neighboring cells an actual data transmission is taking place. If MIMO transmission is taking place in neighboring cells, it is in addition enabled for a UE to know how many streams are transmitted in such cells, and which precoding weights, etc. have been chosen, thus enabling to determine the actual interference signature received from these neighboring cells.

The above-described procedures and functions may be implemented by respective functional elements, processors, or the like, as described below.

While in the foregoing exemplary embodiments of the present invention are described mainly with reference to methods, procedures and functions, corresponding exemplary embodiments of the present invention also cover respective apparatuses, network nodes and systems, including both software and/or hardware thereof.

Respective exemplary embodiments of the present invention are described below referring to Figure 6, while for the sake of brevity reference is made to the detailed description of respective corresponding schemes, methods and functionality, principles and operations according to Figures 1 to 5.

In Figure 6 below, the solid line blocks are basically configured to perform respective operations as described above. The entirety of solid line blocks are basically configured to perform the methods and operations as described above, respectively. With respect to Figure 6, it is to be noted that the individual blocks are meant to illustrate respective functional blocks implementing a respective function, process or procedure, respectively. Such functional blocks are implementation-independent, i.e. may be implemented by means of any kind of hardware or software, respectively. The arrows and lines interconnecting individual blocks are meant to illustrate an operational coupling there-between, which may be a physical and/or logical coupling, which on the one hand is implementation- independent (e.g. wired or wireless) and on the other hand may also comprise an arbitrary number of intermediary functional entities not shown. The direction of arrow is meant to illustrate the direction in which certain operations are performed and/or the direction in which certain data is transferred .

Further, in Figure 6, only those functional blocks are illustrated, which relate to any one of the above-described methods, procedures and functions. A skilled person will acknowledge the presence of any other conventional functional blocks required for an operation of respective structural arrangements, such as e.g. a power supply, a central processing unit, respective memories or the like. Among others, memories are provided for storing programs or program instructions for controlling the individual functional entities to operate as described herein. Figure 6 shows a schematic diagram of exemplary apparatuses according to exemplary embodiments of the present invention.

In view of the above, the thus illustrated apparatuses 10 and 20 are suitable for use in practicing the exemplary embodiments of the present invention, as described herein.

The thus illustrated apparatus 10 may represent a (part of a) terminal such as a UE (e.g. a modem thereof), and may be configured to perform a procedure and/or exhibit a functionality as evident from any one of Figures 1 to 3. The thus illustrated apparatus 20 may represent a (part of a) network element (e.g. a modem thereof), and may be configured to perform a procedure and/or exhibit a functionality as evident from any one of Figures 1 to 3.

As indicated in Figure 6, according to exemplary embodiments of the present invention, each of the apparatuses 10/20 comprises a processor 11/21, a memory 12/22 and an interface 13/23, which are connected by a bus 14/24 or the like, and the apparatuses may be connected via a link, respectively.

The processor 11/21 and/or the interface 13/23 may also include a modem or the like to facilitate communication over a (hardwire or wireless) link, respectively. The interface 13/23 may include a suitable transceiver coupled to one or more antennas or communication means for (hardwire or wireless) communications with the linked or connected device(s), respectively. The interface 13/23 is generally configured to communicate with at least one other apparatus, i.e. the interface thereof. The memory 12/22 may store respective programs assumed to include program instructions or computer program code that, when executed by the respective processor, enables the respective electronic device or apparatus to operate in accordance with the exemplary embodiments of the present invention.

In general terms, the respective devices/apparatuses (and/or parts thereof) may represent means for performing respective operations and/or exhibiting respective functionalities, and/or the respective devices (and/or parts thereof) may have functions for performing respective operations and/or exhibiting respective functionalities.

When in the subsequent description it is stated that the processor (or some other means) is configured to perform some function, this is to be construed to be equivalent to a description stating that a (i.e. at least one) processor or corresponding circuitry, potentially in cooperation with computer program code stored in the memory of the respective apparatus, is configured to cause the apparatus to perform at least the thus mentioned function. Also, such function is to be construed to be equivalently implementable by specifically configured circuitry or means for performing the respective function (i.e. the expression "processor configured to [cause the apparatus to] perform xxx-ing" is construed to be equivalent to an expression such as "means for xxx-ing").

In its most basic form, according to exemplary embodiments of the present invention, the apparatus 10 or its processor 11 is configured to perform acquiring neighbor cell activity information, said neighbor cell activity information being indicative of transmission properties regarding at least one cell being a neighboring cell to a serving cell on the basis of a signaling on a downlink control or a downlink grant channel or a broadcast channel from a network side, and estimating a measure of neighbor cell interference properties on the basis of the acquired neighbor cell activity information.

Accordingly, stated in other words, the apparatus 10 may comprise respective means for acquiring and means for estimating .

In its most basic form, according to exemplary embodiments of the present invention, the apparatus 20 or its processor 21 is configured to perform preparing neighbor cell activity information indicative of transmission properties regarding at least one cell being a neighboring cell to a serving cell, and signaling the prepared neighbor cell activity information on a downlink control or a downlink grant channel or a broadcast channel towards a terminal in the serving cell .

Accordingly, stated in other words, the apparatus 20 may comprise respective means for preparing and means for signaling .

For further details regarding the operability/functionality of the individual apparatuses, reference is made to the abode description in connection with any one of Figures 1 to 4, respectively. According to exemplarily embodiments of the present invention, the processor 11/21, the memory 12/22 and the interface 13/23 may be implemented as individual modules, chips, chipsets, circuitries or the like, or one or more of them can be implemented as a common module, chip, chipset, circuitry or the like, respectively.

According to exemplarily embodiments of the present invention, a system may comprise any conceivable combination of the thus depicted devices/apparatuses and other network elements, which are configured to cooperate as described above.

In general, it is to be noted that respective functional blocks or elements according to above-described aspects can be implemented by any known means, either in hardware and/or software, respectively, if it is only adapted to perform the described functions of the respective parts. The mentioned method steps can be realized in individual functional blocks or by individual devices, or one or more of the method steps can be realized in a single functional block or by a single device.

Generally, any method step is suitable to be implemented as software or by hardware without changing the idea of the present invention. Such software may be software code independent and can be specified using any known or future developed programming language, such as e.g. Java, C++, C, and Assembler, as long as the functionality defined by the method steps is preserved . Such hardware may be hardware type independent and can be implemented using any known or future developed hardware technology or any hybrids of these, such as MOS (Metal Oxide Semiconductor), CMOS (Complementary MOS), BiMOS (Bipolar MOS), BiCMOS (Bipolar CMOS), ECL (Emitter Coupled Logic), TTL (Transistor-Transistor Logic), etc., using for example ASIC (Application Specific IC (Integrated Circuit)) components, FPGA (Field-programmable Gate Arrays) components, CPLD (Complex Programmable Logic Device) components or DSP (Digital Signal Processor) components. A device/apparatus may be represented by a semiconductor chip, a chipset, or a (hardware) module comprising such chip or chipset; this, however, does not exclude the possibility that a functionality of a device/apparatus or module, instead of being hardware implemented, be implemented as software in a (software) module such as a computer program or a computer program product comprising executable software code portions for execution/being run on a processor. A device may be regarded as a device/apparatus or as an assembly of more than one device/apparatus, whether functionally in cooperation with each other or functionally independently of each other but in a same device housing, for example.

Apparatuses and/or means or parts thereof can be implemented as individual devices, but this does not exclude that they may be implemented in a distributed fashion throughout the system, as long as the functionality of the device is preserved . Such and similar principles are to be considered as known to a skilled person.

Software in the sense of the present description comprises software code as such comprising code means or portions or a computer program or a computer program product for performing the respective functions, as well as software (or a computer program or a computer program product) embodied on a tangible medium such as a computer-readable (storage) medium having stored thereon a respective data structure or code means/portions or embodied in a signal or in a chip, potentially during processing thereof.

The present invention also covers any conceivable combination of method steps and operations described above, and any conceivable combination of nodes, apparatuses, modules or elements described above, as long as the above-described concepts of methodology and structural arrangement are applicable.

In view of the above, there are provided measures for support for neighbor cell interference property estimation, particularly at interference-aware receivers. Such measures exemplarily comprise preparation of neighbor cell activity information indicative of transmission properties regarding at least one cell being a neighboring cell to a serving cell and signaling of the neighbor cell activity information on a downlink control or broadcast channel towards a terminal in the serving cell at a network side, and acquisition of the neighbor cell activity information on the basis of the signaling and estimation of a measure of neighbor cell interference properties on the basis of the acquired neighbor cell activity information at a terminal side. The measures according to exemplary embodiments of the present invention may be applied for any kind of network environment, such as for example for communication systems in accordance with any related standards of 3GPP and/or 3GPP2, and so on., e.g . UMTS standards and/or HSPA standards and/or LTE standards (including LTE-Advanced and its evolutions) and/or WCDMA standards.

Even though the invention is described above with reference to the examples according to the accompanying drawings, it is to be understood that the invention is not restricted thereto. Rather, it is apparent to those skilled in the art that the present invention can be modified in many ways without departing from the scope of the inventive idea as disclosed herein .

List of acronyms and abbreviations

3GPP Third Generation Partnership Project

ARQ Automatic Repeat Request

BCH Broadcast Channel

CoMP Coordinated Multipoint Transmission

CRC Cyclic Redundancy Check

DCH Dedicated Channel

ds dual stream (MIMO rank 2 transmission)

E-AGCH E-DCH Absolute Grant Channel

E-DCH Enhanced Dedicated Channel

E-HICH E-DCH Hybrid ARQ Indicator Channel E-RGCH E-DCH Relative Grant Channel

E-RNTI E-DCH Radio Network Transaction Identifier

E-UTRAN Evolved UTRAN

eNodeB evolved Node B (E-UTRAN base station)

FACH Forward Access Channel

H-RNTI HS-DSCH Radio Network Transaction Identifier

HS-DSCH High Speed Downlink Shared Channel

HS-PDSCH High Speed Physical Downlink Shared Channel

HS-SCCH High Speed Physical Downlink Shared Control Channel HSPA High Speed Packet Access

MAC Medium Access Control

MIMO Multiple Input Multiple Output

NBAP Node B Application Part

NodeB UTRAN base station

PCI Precoding Control Indicator

RNC Radio Network Controller

RRC Radio Resource Control

ss single stream (MIMO beamforming)

SIB System Information Block

SIMO Single Input Multiple Output

SINR Signal to Interference plus Noise Ratio

SIR Signal to Interference Ratio

SISO Single Input Single Output

TS Technical Specification

TTI Transmission Time Interval

UE User Equipment

UMTS Universal Mobile Telecommunications System

UTRAN Universal Terrestrial Radio Access Network

WCDMA Wideband Code Division Multiple Access

Claims

1. A method comprising

acquiring neighbor cell activity information, said neighbor cell activity information being indicative of transmission properties regarding at least one cell being a neighboring cell to a serving cell on the basis of a signaling on a downlink control or a downlink grant channel or a broadcast channel from a network side, and

estimating a measure of neighbor cell interference properties on the basis of the acquired neighbor cell activity information.

2. The method according to claim 1, wherein

3. The method according to claim 1, wherein

the acquiring comprises receiving a command in the signaling from a base station of the serving cell or at least one base station of the at least one neighboring cell and decoding the neighbor cell activity information in the received command, and/or

4. The method according to claim 1, wherein

5. A method comprising

preparing neighbor cell activity information indicative of transmission properties regarding at least one cell being a neighboring cell to a serving cell, and

signaling the prepared neighbor cell activity information on a downlink control or a downlink grant channel or a broadcast channel towards a terminal in the serving cell .

6. The method according to claim 5, wherein the signaling comprises transmitting the neighbor cell activity information from a base station of the serving cell or a controller of the base station of the serving cell towards the terminal, and/or

7. The method according to claim 5, wherein

8. The method according to claim 5, wherein

the signaling comprises transmitting a signature structure from at least one base station of the at least one neighboring cell towards the terminal, and/or the signaling comprises dedicated signaling on a downlink channel having a signature structure and slot numbering corresponding to those of a downlink relative grant channel from the at least one base station of the at least one neighboring cell, and/or

9. An apparatus comprising

an interface configured to communicate with at least another apparatus,

a memory configured to store computer program code, and

a processor configured to cause the apparatus to perform :

10. The apparatus according to claim 9, wherein

the signaling comprises dedicated signaling on a downlink control channel or a downlink broadcast channel, and/or the neighbor cell activity information comprises a measure of at least one of a load, a number of active terminals and a transmission power in the at least one neighboring cell .

11. The apparatus according to claim 9, wherein

12. The apparatus according to claim 9, wherein

the signaling comprises dedicated signaling on a downlink channel having a signature structure and slot numbering corresponding to those of a downlink relative grant channel from the at least one base station of the at least one neighboring cell, and/or the neighbor cell activity information comprises at least one of a measure of at least one of a load, a number of active terminals and a transmission power in the at least one neighboring cell, a presence/property information on a transmission in the at least one neighboring cell, a type information regarding a transmission in the at least one neighboring cell, and a precoding control information regarding a transmission in the at least one neighboring cell.

13. An apparatus comprising

an interface configured to communicate with at least another apparatus,

a memory configured to store computer program code, and

a processor configured to cause the apparatus to perform :

preparing neighbor cell activity information indicative of various transmission properties regarding at least one cell being a neighboring cell to a serving cell, and

14. The apparatus according to claim 13, wherein

the processor is configured to cause the apparatus to perform transmitting the neighbor cell activity information from a base station of the serving cell or a controller of the base station of the serving cell towards the terminal, and/or

15. The apparatus according to claim 13, wherein the processor is configured to cause the apparatus to perform transmitting a command including the neighbor cell activity information from a base station of a serving cell or at least one base station of the at least one neighboring cell towards the terminal, and/or

16. The apparatus according to claim 13, wherein

17. A computer program product comprising computer-executable computer program code which, when the program is run on a computer, is configured to cause the computer to carry out the method according to any one of claims 1 to 4 or 5 to 8.