GB2494483A

GB2494483A - Partial reception

Info

Publication number: GB2494483A
Application number: GB1203652.1A
Authority: GB
Inventors: Minna Helena Kaukasalo; Mika Ventola
Original assignee: Renesas Mobile Corp
Current assignee: Renesas Electronics Corp
Priority date: 2012-03-01
Filing date: 2012-03-01
Publication date: 2013-03-13
Anticipated expiration: 2032-03-01
Also published as: GB201203652D0; GB2494483B

Abstract

The method described relates to sending repeated transmission units from a transmitter to a receiver such that data is transmitted M times in M transmission units. The receiver may use the first i received units 402, where i<M, to attempt to successfully decode the received data. The received units are combined 404 and compared to a threshold range 412, which is a threshold 406 +/- a determined margin 408, and if the result or decision is inside the range the receiver continues to receive the next repeated transmission unit(s) 414. If the result/decision is outside of the range a satisfactory/reliable result is determined and a decision is made 416. Battery saving is made as the receiver may stop reception of further repeated transmission units when the decision is determined to be reliable and the decision is made 416. The range may have a size which approaches zero, linearly or non-linearly, as i increases. The comparison may be based on a power or amplitude of the received signal. Figure 7 shows as example wherein a range between decision threshold t to a decision threshold +t is determined and compared a received signal r with a probability density. The method may, for example, be used in a E-HICH, E-DCH Hybrid ARQ Indicator Channel or E-RGCH, E-DCH Relative Grant Channel.

Description

Apparatus and method for communication

Technical Field

The invention relates generally to wireless communication networks. round

The following description of background art may include insights, discoveries, understandings or disclosures, or associations together with disclosures not known to the relevant art prior to the present invention but provided by the invention. Some of such contributions of the invention may be specificafly pointed out below, whereas other such contributions of the invention will be apparent from their context.

One way to control the quality of a communication link in a wireless system is to include repetition to the data that is transmitted on the link. The transmission power used in the transmission of the repeated data can reduced compared to the situation where data is transmitted without repetition and still an 1 5 acccptable detection error level is achieved.

The number of repetitions is generally specified in specifications. Thus there may be eases where the receiving end could successfully decode the data even before all repetitions have been received. This is denoted in the literature as partial reception. In partial reception, if the data has been decoded successfully before all repetitions have been received the hardware at the receiving end can be turned off for the duration of remaining repetitions. In addition, some latency may be avoided as the data is decoded faster.

Thus, with partial reception method, the receiver does not use all the transmitted data if a reliable decision can be made before all the information is received. The idea of the partial reception method is to combine the information from the transmitted packets slot by slot until a reliable decision can be made.

The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the invention. It is not intended to identify key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concepts of the invention in a simplified form as a prelude to a more

detailed description that is presented later.

According to an aspect of the present invention, there is provided an apparatus for use in a communication system, the apparatus having processor means arranged: obtain a quantity related to received signal level of i received transmission units from a data transmitted in M transmission units where i < M; determine at least one threshold for the quantity; determine a range having an upper and a lower limit which are determined on the basis of the at least one thrcshol& compare the quantity to the range; and make a decision about the data if the quantity is outside the range and stop the reception of the rest of the transmission units comprising the data.

According to another aspect of the present invention, there is provided an apparatus for use in a communication system, comprising: means for obtaining a quantity related to received signal level of i first received transmission units from a data transmitted in M transmission units where i C lvi; means for determining at least one threshold for the quantity; means for determining a range having an upper and a lower limit which are determined on the basis of the at least one threshold; means for comparing the quantity to the range; and means for making a decision about the data if the quantity is outside the range and stop the reception of the rest of the transmission units comprising thc data.

According to another aspect of the present invention, there is provided a method in a communication system, comprising: obtaining a quantity related to received signal level of i first received transmission units from a data transmittcd in M transmission units where i C M; determining at least one threshold for the quantity; determining a range having an upper and a lower limit which are determined on the basis of the at least onc threshold; comparing thc quantity to the range; and making a decision about the data if the quantity is outside the range and stop the reception of the rest of the transmission units comprising the data.

Further aspects and embodiments of the present invention will become apparent from the following description, drawings and claims.

Brief Description of the Drawings

Some embodiments of the present invention arc described below, by way of example only, with reference to thc accompanying drawings, in which Figure 1 is a schematic diagram that illustrates an example of a communication environment; Figure 2 is a flowchart illustrating an example embodiment of the invention Figure 3 is a schematic block diagram that illustrates an example of an apparatus applying embodiments of the invention; Figure 4 is a flowchart illustrating an example embodiment of the invention; Figure 5 is a graph that illustrates an example of two level decision making; Figures 6A to 6C are timing diagrams that illustrate an example of the usage of a range, Figure 7 is a graph that illustrates an example of three level decision making; and Figure 8 is a graph that shows an example of performance results for an F-HICI-1 receiver.

Detailed Description

Embodiments are applicable to user equipment (UE), transceiver, modem, corresponding components, and/or to any communication system or any combination of different communication systems that support required functionality.

The protocols used, tile specifications of commumcatiori systems, servers and user terminals, especially in wireless communication, develop rapidly. Such development may require extra changes to an embodiment. Therefore, all words and expressions should be interpreted broadly and they are intended to illustrate, not to restrict, embodiments.

Many different radio protocols to be used in communications systems exist. Some examples of different communication systems are the universal mobile telecommunications system (UMTS) radio access network (UTRAN or E-LJTRAN), 1-ISPA (High Speed Packet Access), long term evolution (LTE, known also as E-UTRA), long term evolution advanced (LTE-A), Wireless Local Area Network (WLAI4) based on IEEE 802.1 Istardard, worldwide interoperability for microwave access (WiMAX), Bluetooth®, personal communications services (PCS) and systems using ultra-wideband (IJWB) technology. IEEE refers to the Institute of Electrical and Electronics Engineers. For example, LTE and LU-A arc developed by the Third Generation Partncrship Project 3GPP.

Figure 1 illustrates a simplified view of a communication environment only showing some elements and functional entities, all being logical units whose implementation may differ from what is shown. The connections shown in Figure 1 are logical connections; the actual physical connections may be different. It will be apparent to a person skilled in the art that the systems also comprise other functions and structures. It should be appreciated that the functions, structures, elements and the protocols used in or for communication are irrelevant to the actual invention.

Therefore, they need not to be discussed in more detail here.

In the example of Figure 1, a radio system based on HSPA (High Speed Packet Access) network elements is shown. However, the embodiments described in these examples arc not limited to radio systems employing HSPA but can also be implemented in other corresponding radio systems.

The simplified example of a network of Figure 1 comprises a Radio Network Controller 100 and a Core Network 102. The Core network 102 provides a connection to Internet 104 and other parts of the network. Figure 1 shows aNodeB 106 serving a cell 108. In this example, the NodeB 106 is connected to the RNC 100 and the Core 102.

In the example of Figure 1, user equipment UE 116 is camped on the NodeB 106.

The NodcB 106 takes care of the radio interface, The RNC 100 controls the radio resources of the NodeBs connected to it. Details of the communication system arc not relevant regarding the embodiments of the invention.

User equipment (UE) refers to a portable computing device. Such computing devices may include wireless mobile communication devices operating with or without a subscriber identification module (SIM), including, but not limited to, the following types of devices: mobile phone, smartphone, personal digital assistant (PDA), tablet computer, laptop computer.

In communication systems, one method used to increase the quality of communication links is the use of repetition. Data may be transmitted in more than one transmission units. In the receiving side the multiple transmission units comprising the same data arc combined and reliably detected.

Two examples of the downlink channels of Fligh Speed Packet Access (HSPA) system which use repetition arc E-FIICH and E-RGCH channels. The E-DCH Hybrid ARQ Indicator Channel (E-HICH) is one of Enhanced Dedicated Channels (E-DCH) transmitted by NodeB. E-HICH is a downlink channel used by the NodeB to request retransmissions from UE as a part of hybrid ARQ (Automatic Repeat-reQuest) mechanism. Relative Grant Channel ([-RGCH) is used by the NodeB to indicate to the UE whether to increase, decrease or keep unchanged the transmit power level of the E-DCH.

For each channel the transmitted message is repeated several times in the applied E-DCH transmission time interval (TTI). For the E-HTCH thc repetition may depend on the used E-DCH TTI length. For E-RGCH the repetition may depend also on the transmitting Node B; whether the Node B is in a serving radio link set or is a non-serving radio link. Table I lists the repetition in h-I-ItCH and E-RGCH channels

defined in 3GPP specifications.

Transmitted channel E-DCH TTI 10 ms E-DCH TTI 2ms E-HICH repeated 12 times repeated 3 times E-RGCH (serving radio link set) repeated 12 times repeated 3 times E-RGCH (non-serving radio link repeated 15 times repeated 15 times set) __________________________ ________________________ Table 1: The repetition of 1 slot message in the E-HICH and E-RGCH control channels NodeB controls the downlink channels in USPA downlink. Furthermore, NodeB may also decide that the channels arc not power controlled at all. Power control is a challenging task as the propagation and interference conditions vary a lot in the network and therefore it is possible that NodeB allocates more power for the transmission of the HSPA downlink channels than the receiver would actnally require.

In such cases it is possible to stop receiving the channel transmitted with repetition before all information is received. A shorter reception time would benefit the U[ especially when CPC (Continuous Packet Connectivity) is applied in the system. When CPC is applied, the connection between NodeB and UE is maintained even when thcre arc inactivity periods in packet transmission. When the reception is completed earlier, the receiver or some parts of the receiver could be turned off during the reception gaps.

The shorter reccption time of HSTJPA downlink channels can thcn result in power savings on the receiver, which can turn into longer battery life.

HSPA channels arc used here merely as an example of channels where repetitions arc used. Embodiments of the invention are not limited to any particular channels or systems but may be applied in any system where data is transmitted using rcpetftion.

In an embodiment of the invention, a receiver receiving a transmission using repetition does not use all the transmitted data if a reliable decision about the transmitted information can be made before all the information is received. This may be denoted as partial reception. In partial reception the information from the transmitted packets can be combined or soil combined until a reliabic decision can be made. The combining may be done slot by slot, subframe by subframe or frame by

frame, for example.

The conventional way of making the decision of transmitted E-HICH or E-RGCI-1 data is to compare the received signal level against a decision threshold after all the relevant information is received. The final decision depends on which side of the dccision threshold the received signal level is. There can be either one or two decision thresholds depending on the transmitted channel and which transmitter is transmitting the signal.

In an embodiment, a slot-by-slot threshold is defined each time a slot (or a transmission unit) comprising repeated data is received. A range having an upper and lower limit is determined on the basis of the slot-by-slot threshold. In an embodiment, a margin is determined in addition to the slot-by-slot threshold. In some embodiments, the margin may be largest (or highest) for the first received slot and for each additional received slot, the margin decreases towards zero. The range having an upper and a lower limit may be determined on the basis of the slot-by-slot threshold and the margin. A decision about the data may be made if the received signal level is outside the range. If the final decision is not made before the relevant data from entire TTI is received, the final decision is made with a zero margin, i.e. the final decision is made with the slot-by-slot threshold without the use of the range.

Figure 2 is a flowchart illustrating an example embodiment of the invention. The process starts at step 200.

In stcp 202, an apparatus is configured to obtain a quantity related to received signal level of i received transmission units from a data transmitted in M transmission units where i C M. In step 204, the apparatus is configured to determine at least one threshold for the quantity.

In step 206, the apparatus is configured to determine a range having an upper and a lower limit which are determined on the basis of the at least one threshold and the margin.

In step 208, the apparatus is configured to compare the quantity to the range.

In step 210, if the quantity is outside the range the apparatus is configured to make a decision about the data and stop the reception of the rest of the transmission units comprising the data.

The process ends in step 212.

Figure 3 illustrates a simplified example of a device in which some embodiments of the invention may be applied. In some embodiments, the device may be user equipment UE or a respective device communicating with a base station or a NodeB of a communications system.

It should be understood that the apparatus is depicted herein as an example illustrating some embodiments. It will be apparent to a person skilled in the art that the device may also comprise other functions and/or structures and not all described functions and structures are required. Although the device has been depicted as one entity, different modules and memory may be implemented in one or more physical or logical entities. In addition, the device may be a part of another device.

The device of the example includes a control circuitry or a processing circuit (CNTL) 300 configured to control at least part of the operation of the device.

The device may comprise a memory (MEM) 302 for storing data.

1 5 Furthermore the memory may store software (PROG) 304 executable by the control circuitry 300. The memory may be integrated in the control circuitry.

The dcvicc comprises a transeciver (TRX) 306. The transceiver is operationally connected to the control circuitry 300. It maybe connected to an antenna arrangement (not shown).

The software 304 may comprise a computer program comprising program code means adapted to cause the control circuitry 300 of the device to control a transceiver 306.

The device may further comprisc uscr interface (UI) 310 operationally connected to the control circuitry 300. The uscr interface may comprise a display which may be touch sensitive, a keyboard or keypad, a microphone and a speaker, for

example.

The control circuitry 300 may be configured to determine a threshold and a margin, and a range on the basis of the threshold and the margin.

Embodiments of the invention may be realized in a baseband modem of UE or corresponding transceiver or receiver.

Figure 4 is another flowchart illustrating an example embodiment of the invention in an apparatus. The apparatus may be user equipment. The embodiment starts at step 400.

In step 402, the apparatus is configured to initiate the reception of data transmitted by a transmitter in M transmission units by receiving i transmission units where i cM. Thus, transmitter such as a NodeB employs repetition in transmission by repeating the samc data in M transmission units such as time slots.

in step 404, the apparatus is configured to combine or soft combine the i received transmission units to obtain a quantity related to received signal level. The quantity may be related to the amplitude or power of the received signal. i i equals I combining is not needed as the quantity may be calculated from a single transmission unit.

In stcp 406, the apparatus is configured to determine at least one slot-by-slot threshold for the quantity.

In step 408, the user equipment is configured to determine a margin. In an embodiment, the size of the margin depends on the number i of the received transmission units.

in step 410, the apparatus is configured to determine a range by determining the upper limit and lower limit of the range. In two level decision making case, the apparatus is configured to determine a range by determining the upper limit of the range by adding the margin to the slot-by-slot threshold and the lower limit of the range by subtracting the margin from the slot-by-slot threshold. In casc of multi (e.g. three) level decision making case, the apparatus is configured to determine a range by determining the upper limit of the range by adding the margin to the largest slot-by-slot threshold and the lower limit of the rangc by subtracting the margin from the lowest slot-by-slot threshold.

In step 412, the apparatus is configured to compare the quantity to the range.

if the quantity is inside the rangc and i is smaller than M, a final decision of the data will not be made yet. in such case, the apparatus is configured to receive one or more transmission units in step 414. The number i is thus increased. The process continues in step 404.

If the quantity is outside the range the apparatus will make a decision about the data in step 416 and stop the reception of the rest of the transmission units comprising the data.

The process ends in step 418.

Let us study the determination of the margin in more detail using a two-level decision making embodiment as an example. Let a conventional two-level decision making be defined as 1+1 ifr>t -, (1) (-1 ifr<t where P is the final dccision made about a transmitted message, r is thc signal level in the decision making point and t is the decision threshold applied when all data is received. Flow P = +1 and I =-1 are interpreted depends on the data in question. It should be noted that values +1 and -are only illustrative examples and may in practice be other numerical values as well.

An example of a two level decision making is illustrated in Figure 5 forE-HICH channel. The three distributions 500, 502, 504 of figure 5 illustrate the probability density functions of the received signal when negative, positive is transmitted or when there is no transmission. A decision threshold t 506 is also shown.

A received signal that is above the threshold will be interpreted as ACK and everything below the threshold is interpreted as NACK. The figure illustrates a situation when all data has been received.

In an embodiment when partial reception is applied, the slot-by-slot threshold is updated after each reception of a repeated transmission unit or slot. Let in llowing be the slot-by-slot threshold that is calculated after i combined slots. The slot-by-slot threshold t is cxpected to get more accurate as the number of combined slots increases. There are many methods known in the art that can be used to determine the slot-by-slot threshold. For example, the calculation of the threshold can be based on estimating the noise variance of thc received signal. As more slots are received, more accurate the estimate gets. The slot-by-slot threshold can be achieved by multiplying the variance estimate with a fixed value, to adjust the threshold to such a place that performance requirements are met, for example. This fixed value can be found by tuning.

In an embodiment, an extra margin is taken into account in addition to the slot-by-slot threshold t. Let us refer to this margin as margin X. The size of the margin X depends on the number of received slots. An example of the decision making is then as follows: (+1 ifr>t +X (2) C. -1 ifr1t1 -where r1 is the received signal value at the decision making after i slots are received.

In conventional receivers utilising partial reception the noise and transmitted positive and negative signal may be similar in the receiver as a small number of slots are combined. Thus, after a first received slot by the conventional receiver, the three different options (negative, positive, no transmission) for the signal may be too similar. This would result in high missed ACK rates. In an embodiment, the margin X is largest for the first slot and then decreases towards zero as more slots are received. This is reasonable as when more slots are combined from the same TTI the similarities between the positive, negative and noise signals decrease. Thus, the slot-by-slot threshold may be more accurate. The decrease of the margin may be linear or non-linear.

In an embodiment, the margin X is defined according to X1=tx (Z-ri), (3) where i is the number or received transmission units, Z a predetermined constant, t slot-by-slot threshold and X margin to bc combined to the slot-by-slot threshold t for i received transmission units. M is the number of transmission units used in the repetition, i.e. the total number of units in which the same data is transmitted. It should be noted that the above equation is merely an illustrative example of the calculation of the margin. It provides a linear decreasing of the margin as the number of transmission units increases.

Bascd on equations (2) and (3), the final decision may be obtained by performing the comparison between quantity r and slot-by-slot threshold t to obtain a decision value according to -I-i ifr»= t+ t1x(Z-i) -1 if r1 C t -t x (Z -i) where quantity r1 is obtained by soft combining the i transmission units received so far, t is the slot-by-slot threshold for i received transmission units.

Thus, a range is determined using the slot-by-slot threshold t1 and the margin. If the quantity is outside the range a decision will be made. If the quantity is within the range a dccision will not be made.

Even though the number of applied decision making events increases with partial reception in the above example, it is controlled only with one constant, Z. Suitable value for Z may be determined by tuning. Tuning can be based on finding a balance between missed ACK, false ACK and missed NACK rates.

An example of the usage of the margin is illustrated in Figures 6A to 6C.

The figures illustrate an example of the margin usage when 12 E-HICH slots arc transmitted from E-DCH serving cell in 10 ms TTI. Figure 6A shows the situation after the first slot has been received. The slot-by-slot decision threshold is ti and the range is in this example thus the area between tLxJ and where the lower limit tLxl = tlXl and upper limit tp)< = t1+X1. Thus, the quantity is determined to be -1 if ifs value is below tuxi and +1 if it is above txi. Figure ÔB shows the situation after six first slots have been received. The slot-by-slot decision threshold is to and the lower and upper limits of the range are t1 = t6-X6 and tx6 = t6-4-X0. Finally Figure 6C illustrates the situation when all transmission units or slots have been received.

In some embodiments, the range need not be symmetrical regarding the threshold or thresholds.

In some embodiments, the margin X combined with the slot-by-slot threshold t1 decreases as number of combined slots used in decision making increases.

For example, no margin is used after all the E-HICH slots from E-DCH TTI carrying the same acknowledgement are received.

The two-level decision making process described above can be extended to be used also in three-level decision making. One example of such channel is E-RGCH that is transmitted from a serving E-DCH radio link. A receiver is making decision between UP, HOLD and DOW/N. Figure 7 illustrates the case. The figure illustrates a situation when all data has been received.

The three distributions 700, 702, 704 of figure 7 illustrate the probability density functions of the received signal when negative, positive is transmitted or when there is no transmission. A decision thresholds +t 706 and -t 708 are also shown. A received signal that is above the threshold +t will be decided as UP and everything below the negative threshold -t is interpreted as DOWN. HOLD decision falls between the thresholds.

In an embodiment, equation (4) may be applied to the example situation.

The final decision may be obtained by performing the comparison between quantity r and the highest slot-by-slot threshold tRXj and the lowest slot-by-slot threshold tTxj to obtain a decision value f according to (+1 if r1 »= tRXj + t x (Z-i) 30, (5) if r1 C tLXj tuxix(Z i) where quantity r is obtained by combining or soft combining i received transmission units. Thus, the range is determined by adding the margin to the highest threshold and subtracting the margin from the lowest threshold. In an embodiment, the HOLD decision can be made after all transmission units have been received.

Utilising some embodiments of the invention may help to decrease the reception time in a rcceivcr as a decision regarding the data may bc obtaincd before all data is transmitted. An example of the reduction can be taken from the two-level decision making for E-HICH channel with 3GPP channel profile referred to as VehA3O G = 0dB with E-HICI-1 transmissionpowerof-34dB fromthe serving E-DCH cell where G refers to the link geometry. Table 2 illustrates results with the above set up. In this setup the performance of the conventional receiver, measured as missed ACK rate, is at vcry low level, around i03.

_____________________ _________________________ _________________________

Information signal Average number of slots Saved reception lime received compared to the for a decision reception time of a ________________________ _____________________________ conventional receiver Positivc signal 5.96 % 50.3 % transmitted _______________________________ ______________________________ Negative signal 5.50 % 54.2 % transmitted _____________________________ ____________________________ Nothing transmitted 10.18% 15.2% Table 2: Number of average slots received for a decision about transmitted message on

E-HICH

This reduction iii the reception time is beneficial when CPC (Continuous Packet Connectivity) is applied in the system, for example. Whcn CPC is applied, the reception gaps in the tiE can be utilized by shutting down the receiver or some part of the receiver. By using the above described solution, the turn off-period can be increased. It can bc the case e.g. when Grant Monitoring is the last thing to perform before a total reception gap.

In addition in an embodiment, the number of required operations can be reduced in thc reception of E-HICH. The reduction in thc operations results from thc fact that the logic added on top of a conventional receiver requires fewer operations than is saved when partial reception is applied.

Table 3 illustrates an example of savings in the number of required operations assuming a similar set up (VchA3O G=OdB) as used in connection with Table2 described above. It may be impossible to define exactly how many calculations can be saved but the number can be roughly estimated. Estimation requires some assumptions about the receiver: 1) If the receiver makes decision about the transmitted message after N slots, each part of the E-HICH reception is stopped after N slots.

21) Widely used ARM Cortex-R4 architecture is assumed to be used as implementation hardware.

The first assumption is not the ease as each part of the receiver, at least in the beginning, arc running continuously. The second assumption is needed in order to make each basic operation comparable with each other. It should be noted that the above assumptions relate only to this particular example and not to the embodiments of the invention in general.

The estimates of the savings are shown in Table 3 for each four basic operation separately and then total saving rates. The reference point is the conventional receiver that is not applying the partial reception method.

The results indicate that the total saving is very close to the relative values of the time saved in partial reception. This implies that the additional calculations required by the partial reception logic added on top of conventional receiver is light compared to the achieved savings.

rositive signal Addition Multiplication Square root Comparison transmitted [%I l%l 1%l [%I Saved -12,28 -37,96 0,09 0,02 operation ____________ _______________ _____________ _______________ Saving in total -50,13 % _______________ _____________ ______________ Negative Addition Multiplication Square root Comparison signal I%l 10/n] [°°I I%l transmitted Saved -13,22 -40,88 0,08 0,02 operation ____________ ________________ ______________ ________________ Saving in total -54,00 % _______________ _____________ _______________ Nothing Addition Multiplication Square root Comparison transmitted [°/°I I%I %] [0/ni Saved -3,67 -11,36 0,17 0,03 operation ____________ _______________ _____________ _______________ Saving in total -14,83 % Table 3: The complexity metric Cm defined for the E-HTCH receiver applying partial reception when positive, negative or nothing is transmitted.

From the performance point of view, a receiver applying embodiments of the invention is similar to a receiver not applying partial reception. Figure 8 show the performance results for an E-HICH receiver which applies an embodiment of the invention by utilising partial reception with a range. The results are from VehA 30 G = 0dB in single link case. In addition to the results for a conventional receiver 800 and the partial reception receiver 802 the figure shows corresponding 3GPP requirement 804. In this particular example results show that there is insignificant difference between the conventional receiver 800 and the partial reception receiver 802.

In some embodiments, the proposed usc of the range increases the accuracy and the reliability of the decision making.

The steps and related functions described in the above and attached figures arc in no absolute chronological order, and some of the steps may be performed simultaneously or in an order differing from the given one. Other functions can also be executed between the steps or within the steps. Some of the steps can also be left out or replaced with a corresponding step.

The apparatuses or controllers able to perform the above-described steps may be implemented as an electronic digital computer, processing system or a circuitry which may comprise a working memoiy (RAM), a central processing unit (CPU), and a system clock. The CPU may comprise a set of registers, an arithmetic logic unit, and a controller. Thc processing system, controller or the circuitry is controlled by a sequence of program instructions transferred to the CPU from the RAM. The controller may contain a number of microinstructions for basic operations. The implementation of microinstructions may vary depending on the CPU design. The program instructions may be coded by a programming language, which may be a high-level programming language, such as C, Java. etc., or a low-level programming language, such as a machine language, or an assembler. The electronic digital computer may also have an operating system, which may provide system services to a computer program written with the program instructions.

As used in this application, the term circuitry' refers to all of the following: (a) hardware-only circuit implementations, such as implementations in only analog and/or digital circuitry, and (b) combinations of circuits and software (and/or firmware), such as (as applicable): (i) a combination of processor(s) or (ii) portions of processor(s)/software including digital signal processor(s), software, and memory(ics) that work together to cause an apparatus to perform various thnctions, and (e) circuits, such as a microprocessor(s) or a portion of a microprocessor(s), that require software or firmware for operation, even if the software or firmware is not physically present.

This definition of circuitry' applies to all uses of this term in this application. As a further example, as used in this application, the term circuitry' would also cover an implementation of merely a processor (or multiple processors) or a portion of a processor and its (or their) accompanying software and/or firmware. The term circuitry' would also cover, for cxamplc and if applicable to the particular element, a baseband integrated circuit or applications processor integrated circuit for a mobile phone or a similar integrated circuit in a server, a cellular network device, or another network device.

An embodiment provides a computer program embodied on a distribution medium, comprising program instructions which, when loaded into an electronic apparatus, arc configured to control the apparatus to execute the embodiments 1 5 described above.

The computer program may be in source code form, object code form, or in some intermediatc form, and it may be stored in some sort of carrier, which may be any entity or device capable of carrying the program. Such carriers include a record medium, computer memory, read-only memory, and a software distribution package, for example. Depending on the processing power needed, the computer program may be executed in a single electronic digital computer or it may be distributed amongst a number of computers.

The apparatus may also be implemented as one or more integrated circuits, such as application-specific integrated circuits ASIC. Other hardware embodiments are also feasible, such as a circuit built of separate logic components. A hybrid of these different implementations is also feasible. When selecting the method of implementation, a person skilled in the art will consider the requirements set for the size and power consumption of the apparatus, the necessary processing capacity, production costs, and production volumes, for example.

It will be obvious to a person skilled in the art that, as technology advances, the inventive concept can be implemented in various ways. The invention and its embodiments are not limited to the examples described above but may vary within the scope of the claims.

Claims

<claim-text>Claims 1. An apparatus for usc in a communication system, the apparatus having processor means arrangcd to: obtain a quantity related to rcccivcd signal level of i rcccived transmission units from a data transmitted in M transmission units where i < M; determine at least one threshold for the quantity; determine a rangc having an upper and a lower limit which are determined on the basis of the at least one threshold; compare the quantity to the range; and make a decision about the data if the quantity is outside the range and stop the reception of the rest of the transmission units comprising the data.</claim-text> <claim-text>2. The apparatus of claim 1, arranged to initiate the reception of data transmitted in M transmission units by first receiving i transmission units where i < M; and combine the i received transmission units to obtain a quantity related to received signal level.</claim-text> <claim-text>3. The apparatus of claim 2, arranged, if the quantity was inside the range, to: receive one or more transmission units; perform the combination, determination and comparison steps; and make a decision about the data if the quantity is outside the range and stop the reception of the rest of the transmission units comprising the data.</claim-text> <claim-text>4. The apparatus of any preceding claim, arranged to determine the range, the size of the range depending on the number i of received transmission units.</claim-text> <claim-text>5. The apparatus of any preceding claim, arranged to determine the range having the highest size when i equals and a zero size when M transmission units have been received.</claim-text> <claim-text>6. The apparatus of any preceding claim, arranged to determine the range having a size which linearly approaches zero when i increases.</claim-text> <claim-text>7. The apparatus of any preceding claim 1 to 5, arranged to determine the range having a size which nonlinearly approaches zero when i increases.</claim-text> <claim-text>8. The apparatus of any preceding claim, arranged to determine a margin X according to Xj=tjx (Z-ri), where i is the number or received transmission units, Z a predetermined constant, tithe threshold and X1 the margin for i received transmission units.</claim-text> <claim-text>9. The apparatus of claim 8, arranged to perform the comparison between the quantity r and the range to obtain a decision value according to (+1 ifr »= t+ X1 = t-i ifr1<t-X1' where t1 is the threshold, X1 is the margin for i received transmission units.</claim-text> <claim-text>10. The apparatus of claim 1, wherein the quantity is related to the amplitude or power of the received signal.</claim-text> <claim-text>11. The apparatus of any preceding claim, comprising user equipment of a communication system.</claim-text> <claim-text>12. The apparatus of claim 1, arranged to determine the range by determining the upper limit of the range by adding a margin to a threshold and the lower limit of the range by subtracting a margin from the threshold.</claim-text> <claim-text>13. The apparatus of claim 1, arranged to determine the range by determining the upper limit of the range by adding a margin to the highest threshold and lower limit of the range by subtracting a margin from the lowest threshold.</claim-text> <claim-text>14. An apparatus for use in a communication system, comprising: means for obtaining a quantity related to received signal level of i first received transmission units from a data transmitted in M transmission units where i < M; means for determining at least one threshold for the quantity; means for determining a range having an upper and a lower limit which are determined on the basis of the at least one threshold; means for comparing the quantity to the range; and means for making a decision about the data if the quantity is outside the range and stop the reception of the rest of the transmission units comprising the data.</claim-text> <claim-text>15. The apparatus of claim 14, fUrther comprising means for initiating the reception of the data transmitted in M transmission units by first receiving i transmission units where i < M; means for combining the i received transmission units to obtain the quantity related to received signal level.</claim-text> <claim-text>16. The apparatus of claim 15, further comprising means for receiving one or more transmission units, means for pcrforming the combination, determination and comparison steps, means for making a decision about the data if the quantify is outside the range and stop the reception of thc rest of the transmission units comprising thc data.</claim-text> <claim-text>17. The apparatus of any of claims 14 to 16, fUrther comprising means for dctcrmining the rangc, thc size of the rangc dcpcnding on the number i of received transmission units.</claim-text> <claim-text>18. The apparatus of any of claims 14 to 17, further comprising means for determining the range by determining the upper limit of the range by adding the margin to a threshold and the lower limit of the range by subtracting the margin from the threshold.</claim-text> <claim-text>19. The apparatus of any of claims 14 to 17, further comprising means for determining the range by determining the upper limit of the range by adding a margin to the largest threshold and the lower limit of the range by subtracting a margin from the lowest threshold.</claim-text> <claim-text>20. A method in a communication system, comprising: obtaining a quantity related to received signal level of i first received transmission units from a data transmitted in M transmission units where i < M; determining at least one threshold for the quantity; determining a range having an upper and a lower limit which are determined on the basis of the at least one threshold; comparing the quantity to the range; and making a decision about the data if the quantity is outside the range and stop the reception of the rest of the transmission units comprising the data.</claim-text> <claim-text>21. The method of claim 20, further comprising: initiating the reception of data transmitted in M transmission units by first receiving i transmission units where i < M; and combining the i received transmission units to obtain a quantity related to received signal level.</claim-text> <claim-text>22. The method of claim 20 or 21, further comprising, if the quantity was inside the range: receiving one or more transmission units; performing the combination, determination and comparison steps; and making a decision about the data if the quantity is outside the range and stop the reception of the rest of the transmission units comprising the data.</claim-text> <claim-text>23. The method of any of claims 20 to 22, wherein the size of the range depends on the number i of received transmission units.</claim-text> <claim-text>24. The method of any of claims 20 to 23, further comprising: determining a range having the highest size when i equals 1 and a zero size when M transmission units have been received.</claim-text> <claim-text>25. The method of any of claims 20 to 24, further comprising: determining a range having a size which linearly approaches zero when N increases.</claim-text> <claim-text>26. The method of any of claims 20 to 24, ifirther comprising: determining a range having a size which nonlinearly approaches zero when i increases.</claim-text> <claim-text>27. The method of any of claims 20 to 26, further comprising: determining a margin X1 according to X=tx(Z-ri), where i is the number or received transmission units. Z a predetermined constant, L1 the threshold and X the margin for i received transmission units.</claim-text> <claim-text>28. The method of claim 27, further comprising: performing the comparison between the quantityr and the range to obtain a decision value? according to (+1 ifrj»= t1+ X1 T=1 ifr< t-X' where t is the threshold, X is the margin to be added to the threshold for i received transmission units.</claim-text> <claim-text>29. The method of claim 20, wherein the quantity is related to the amplitude or powcr of the received signal.</claim-text> <claim-text>30. The method of claim 20, further comprising: determining the range by determining the upper limit of the range by adding the margin to a threshold and the lower limit of the range by subtracting the margin from the threshold.</claim-text> <claim-text>31. The method of claim 20, further comprising: determining the range by determining the upper limit of the range by adding a margin to the highest threshold and the lower limit of the range by subtracting a margin from the lowest threshold.</claim-text> <claim-text>32. A computer readable medium comprising a set of instructions, which, when executed on a processing system, causes the processing system to perform the steps of any of claims 20 to 31.Amendments to the Claims have been filed as follows Claims 1. An apparatus for use in a communication system, the apparatus having processor means arranged to: obtain a quantity related to received signal level of i received repeated transmission units from a data transmitted in M repeated transmission units where i < M; determine at least one threshold for the quantity; determine a range having an upper and a lower limit which are determined on the basis of the at least one threshold; compare the quantity to the range; and make a decision about the data if the quantity is outside the range and stop the reception of the rest of the repeated transmission units comprising the data.
2. The apparatus of claim 1, arranged to r initiate the reception of data transmitted in M repeated transmission units 0') by first receiving i repeated trarisutission units where i < M; and 0 combine the i received repeated transmission units to obtain a quantity C) related to received signal level.
3. The apparatus of claim 2, arranged, if the quantity was inside the range, to: receive one or more repeated transmission units; perform the combination, determination and comparison steps; and make a decision about the data if the quantity is outside the range and stop the reception of the rest of the repeated transmission units comprising the data.
4. The apparatus of any preceding claim, arranged to determine the range, the size of the range depending on the number i of received repeated transmission units.
5. The apparatus of any preceding claim, arranged to determine the range having the highest size when i equals 1 and a zero size when M repeated transmission units have been received.
6. The apparatus of any preceding claim, arranged to determine the range having a size which linearly approachcs zero when i increases.
7. The apparatus of any preceding claim I to 5, arranged to determine the range having a size which nonlinearly approaches zero when i increases.
8. The apparatus of any one of the preceding claims, arranged to perform the comparison betwccn a quantity r and the range to obtain a decision value f according to (+1 ifrj»= t1-}-X1 T= t-i ifr<t-X' where r1 is the received signal value at the decision making after i slots are received, t, is the threshold, X, is a margin for i received repeated transmission units.(\J is
9. The apparatus of claim 8, arranged to determine the margin X according Q) to X=tx(Z-Li), where i is the number of received repeated transmission units, Z a predetermined constant. t1 the threshold and X the margin for i received repeated transmission units.
10. The apparatus of claim I, wherein the quantity is related to the amplitude or power of the received signal.
11. The apparatus of any preceding claim, comprising user equipment of a communication system.
12. The apparatus of claim 1, arranged to determine the range by determining the upper limit of the range by adding a margin to a threshold and the lower limit of the range by subtracting a margin from the threshold.
13. The apparatus of claim 1, arranged to determine the range by detcrmining the upper limit of the range by adding a margin to the highest threshold and lower limit of the range by subtracting a margin from the lowest threshold.
14. An apparatus for use in a communication system, comprising: means for obtaining a quantity related to received signal level of i first received repeatcd transmission units from a data transmitted in M repeated transmission units where i <M; means for determining at least one threshold for the quantity; means for determining a range having an upper and a lower limit which are determined on the basis of the at least one threshold; means for comparing the quantity to the range; and means for making a decision about the data if the quantity is outside the 15 range and stop the reception of the rest of the repeated transmission units comprising the data. r0')
15. The apparatus of claim 14, further comprising means for initiating the reception of the data transmitted in M repeated Ct) 20 transmission units by first recciving i repeated transmission units where i < means for combining the i received repeated transmission units to obtain the quantity related to received signal level.
16. The apparatus of claim 15, further comprising, if the quantity was inside the range, means for receiving one or more repeated transmission units, means for performing the combination, determinalion and comparison steps, means for making a decision about the data if the quantity is outside the range and stop the reception of the rest of the repeated transmission units comprising the data.
17. The apparatus of any of claims 14 to 16, further comprising means for determining the range, the size of the range depending on the number i of received repeated transmission units.12. The apparatus of any of claims 14 to 17, further comprising means for determining the range by determining the upper limit of the range by adding a margin to a threshold and the lower limit of the range by subtracting a margin from the threshold.19. The apparatus of any of claims 14 to 17, further comprising means for determining the range by determining the upper limit of the range by adding a margin to the largest threshold and the lower limit of the range by subtracting a margin from the lowest threshold.20. A method in a communication system, comprising: obtaining a quantity related to received signal level of i first received repeated transmission units from a data transmitted in M repeated transmission units where i < M; determining at least one threshold for the quantity; determining a range having an upper and a lower limit which are determined on the basis of the at least one threshold; 0') comparing the quantity to the range; and making a decision about the data if the quantity is outside the range and stop the reception of the rest of the repeated transmission units comprising the data.21. The method of claim 20, thither comprising: initiating the reception of data transmitted in M repeated transmission units by first receiving i repeated transmission units where i < M; and combining the i received repeated transmission units to obtain a quantity related to received signal level.22. The method of claim 20 or 21, further comprising, if the quantity was inside the range: receiving one or more repeated transmission units; performing the combination, determination and comparison steps; and making a decision about the data if the quantity is outside the range and stop the reception of the rest of the repeated transmission units comprising the data.23. The method of any of claims 20 to 22, wherein the size of the range depends on the number i of received repeated transmission units.24. The method of any of claims 20 to 23, further comprising: determining a range having the highest size when i equals I and a zero size when M repeated transmission units have been received.S25. The method of any of claims 20 to 24, further comprising: determining a range having a size which linearly approaches zero when i increases.26. The method of any of claims 20 to 24, further comprising: determining a range having a size which nonlinearly approaches zero when i increases.27. The method of any one of claims 20 to 26, further comprising: performing the comparison between a quantity r and the range to obtain a decision value 1' according to C'%J.. 1+1 ifrj»= t+ X, T I-i ifr< t-X' a) C where r is the received signal value at the decision making after i slots are C') received, t1 is the threshold, X1 is the margin to be added to the threshold for i received repeated transmission units.28. Thc method claim 27, further comprising: determining a margin X according to X1=tx(Z_ ri), where i is the number of received repeated transmission units, Z a predetermined constant, tithe threshold and X the margin for i received repeated transmission units.29. The method of claim 20, wherein the quantity is related to the amplitude or power of the received signal.30. The method of claim 20, thither comprising: determining the range by determining the upper limit of the range by adding a margin to a threshold and the lower limit of the range by subtracting a margin from the threshold.31. The method of claim 20, further comprising: determining the range by determining the upper limit of the range by adding a margin to the highest threshold and the lower limit of the range by subtracting a margin from the lowest threshold.32. A computer readable medium comprising a set of instructions, which, when executed on a processing system, causes the processing system to perform the steps of any of claims 20 to 31. (4 r a) C)</claim-text>