HK1080238A - Reliability detection of channel quality indicator (cqi) and application to outer loop power control - Google Patents

Description

Reliability detection of cqi and application of outer loop power control

Technical Field

The present invention relates generally to channel quality measurement in wireless communications, and more particularly, to a method and apparatus for reliably detecting channel quality and application of outer power loop control thereof.

Background

Today, third generation (3G) mobile communication systems have been standardized to implement efficient and high processing capability Downlink (DL) packet data transmission schemes. In the context of 3G system based Universal Mobile Telecommunications System (UMTS) wideband code division multiple access (W-CDMA), this packet transmission technique is commonly referred to as High Speed Downlink Packet Access (HSDPA), which is feasible under both Frequency Division Duplex (FDD) and Time Division Duplex (TDD) and which is performed at chip rates of 1.28Mcps and 3.84 Mcps.

The following characteristic features are the recognized effectiveness and achievable data processing capabilities for HSDPA: adaptive modulation and coding techniques (AMC), fast hybrid automatic repeat request (hybrid arq), fast feedback mechanism for Uplink (UL) reporting of real-time DL channel quality, radio resource efficient packet scheduling mechanism, and fast short-term DL channel assignment.

Yet another distinguishing feature of HSDPA is that the assignment of an HSDPA base station to a Wireless Transmit and Receive Unit (WTRU) is a function of the WTRU's real-time channel state for the amount of data rate and DL transmit (Tx) power. For example, a user close to the base station may actually receive a high HSDPA data rate with low transmit power, a user far from the base station, or a user facing unfavorable channel conditions, and may only proceed at a reduced data rate for the same or greater amount of assigned DL transmit power.

The real-time HSDPA data rate that a particular user can actually do is generally dependent on 1) path loss, which is based on distance from the serving base station; 2) shielding; 3) a real-time fast decline state; 4) interference at the user's receiving end, caused by the presence of other users in the system; and 5) the channel conditions of the user, such as speed and propagation environment. In other words, the HSDPA data rate is a function of the DL signal-to-interference ratio (SIR) experienced by the user, based on all of these factors, and expressed in terms of the DL data rate that the user can maintain, the DL SIR of the user generally changing over time as a function of these factors.

Knowledge of the DL SIR experienced by the user, or any similar representative route metric (metric value) with this functionality, such as BLER, BER or received signal power combined with received DL interference, is essential for HSDPA base stations to ensure highly efficient HSDPA operation. CDMA systems utilizing HSDPA therefore employ a fast UL layer 1(L1) signaling mechanism that allows a WTRU to periodically report DL SIR to the base station with a fast UL Channel Quality Indicator (CQI). Current FDD specifications allow the configuration of the periodic CQI feedback to be sent every 0 (when CQI reporting is off), 2, 4, 8, 10, 20, 40, 80 or 160 ms in the UL, however, TDD systems do not have periodic CQI feedback, so the CQI is replaced with an ACK/NACK on the high speed shared control channel (HS-SICH) sent every time a DL data block of the HSDPA data channel (HS-DSCH) is received by a WTRU, which is also commonly referred to as CQI reporting in W-CDMA FDD and TDD modes.

The method of measuring CQI performed at a particular WTRU is not standardized, and is certainly practiced by open manufacturers, but the method of how to obtain the reported CQI value is also not standardized. In the FDD standard, there is a table (shown in 3GPP TS 25.321, Medium Access Control (MAC) protocol specification, 5.4.0 (2003-03)) that roughly lists some 30CQI values for increasingly higher data rates, and thus increasingly higher DL SIRs. The reported CQI value in FDD is obtained as follows (in accordance with 3GPP TS 25.214, physical layer procedure (FDD), v5.4.0(2003-03), section 6 a.2): "the UE shall report the highest CQI value in the list to a single HS-DSCH subframe, formatted with the transport block size number of HS-PDSCH coding and modulation, which is equivalent to the reported or lower CQI value, which can be in a three-slot reference period ending the first slot, which is before the start of the first slot, where the reported CQI value is sent and its error probability for the transport block will not exceed 0.1". In TDD, the reporting is different, and the tbs size is reported only if it is in the last received transmission gap (the number of slots at the last HS-DSCH reception) and the transmission results in a bler of 0.1.

For example, in current W-CDMA FDD version 5, the CQI is a 5-bit length information bit sequence encoded in a (20, 5) Reed-Muller coding, the encoded 20-bit length sequence is sent in the UL of a high speed dedicated physical control channel (HS-DPCCH), each user has a separate HS-DPCCH with an adjustable CQI reporting cycle (feedback rate), and a user can report the CQI value on the HS-DPCCH even if the user does not receive data on the HS-DSCH.

As another example, in current W-CDMA TDD versions (3.84Mcps or High Chip Rate (HCR) TDD), the CQI is a 10-bit length information bit sequence that is encoded in a (32, 10) Reed-Muller coding scheme, the encoded 32-bit length code sequence being sent on the UL that is considered part of the HS-SICH, and in current TDD, a CQI transmission can only occur if the user has previously received data on the HS-DSCH in a frame.

Since the reliability of CQI reporting by a WTRU has an impact on HSDPA operation, it is important that an HSDPA base station have a means to determine if the CQI was received in error, which can be avoided by discarding any erroneously received CQI, where it would select the DL data rate and corresponding transmission power of the user that is not appropriate for the DL channel conditions the user is facing. Erroneous CQIs reduce the data throughput of the HSDPA to the user and cause a high degree of interference to other users in the system, which reduces the effectiveness of HSDPA service in W-CDMA systems.

In addition, too many erroneous CQIs received from a particular user are an indication that the DL transmit power setting of the user is not accurate, and the base station or another access network node, e.g., a Radio Network Controller (RNC), will take appropriate action. For example, the RNC can send a higher target UL SIR signal to the user to increase its UL transmit power and reduce the error rate in HS-DPCCH (in FDD) or HS-SICH (in TDD), which is a form of RNC functionality commonly referred to as outer loop power control.

Error detection for receiving UL transmissions in W-CDMA FDD and TDD modes is typically accomplished by performing a Cyclic Redundancy Check (CRC), i.e., when decoding errors occur at the base station, a bit sequence accompanying the data is a reliable indicator of decoding errors. For a CRC to be effective in error detection, the length of the CRC must be significantly larger, however, to avoid having unnecessary processing, the ratio of the CRC length to the actual data length needs to be very small, which in a typical application may be a sequence of hundreds of bits, whereas the CRC may only have 8-24 bits.

Unfortunately, HS-dpcch (fdd) and HS-sich (tdd) are fast L1 UL signaling channels that do not contain any UL data or a sufficient number of L1 signaling bits to effectively utilize CRC, which must normally be at least as large as the data field bits to check in order to provide a sufficient amount of error detection performance, and current HSDPA standards do not use CRC on HS-dpcch (fdd) and HS-sich (tdd).

Thus, based on existing techniques, the network (base station or RNC) has no reliable way to determine whether a CQI is received incorrectly, and the network can only configure the WTRU to use a UL transmit power that is high enough, with a UL target SIR and "experience" derived from simulations that erroneous results are unlikely to occur and are not detrimental to the operation of the HSDPA system, thus providing a reliable way to detect and report the correctness of the received CQI value would be helpful.

Disclosure of Invention

The method of the present invention enables the base station to determine the degree of CQI reliability. The present invention provides a useful reliability detection mechanism for CQI reports received by a HSDPA base station from a WTRU and a received CQI quality reporting mechanism from the HSDPA base station to the RNC to track and adjust a WTRU UL transmit power setting.

A method for improving reliability of a Channel Quality Indicator (CQI) message in a wireless communication network begins by receiving and decoding the CQI message. The metric for each symbol decision in the CQI message is calculated, a maximum decision metric and a second largest decision metric are determined, and the reliability of the CQI message is determined by comparing the maximum decision metric and the second largest decision metric.

A method for improving the reliability of a received message representing the quality of a transmission channel in a wireless communication network is initiated by receiving a Channel Quality Indicator (CQI) message from a wireless transmitting and receiving unit, the CQI message is then decoded and at least two different values representing the decoded CQI message are obtained, the reliability of the CQI message is determined by comparing the at least two values.

A system for determining the quality of a transmission channel in a wireless communication network, the wireless communication system comprising at least one Wireless Transmit and Receive Unit (WTRU) and a base station, the WTRU comprising a generator for generating a Channel Quality Indicator (CQI), the base station comprising receiving means for receiving the CQI, decoding means for decoding the CQI, calculating means for calculating a first decision metric and a second decision metric for the decoded CQI, and comparing means for comparing the first and second decision metrics to determine whether the CQI contains an error.

An integrated circuit constructed in accordance with the present invention includes an input configured to receive a Channel Quality Indicator (CQI) message, decoding means for decoding the CQI message, calculating means for calculating a first decision metric and a second decision metric for the decoded CQI, and comparing means for comparing the first decision metric and the second decision metric to determine whether the CQI message includes an error.

Drawings

Further details of the invention can be taken from the following description of embodiments, given by way of example and with reference to the accompanying drawings, in which:

fig. 1 is a flow chart of a method according to the invention, which is applicable to both FDD and TDD;

fig. 2 is a flow chart of an embodiment of the method according to the present invention, which is applicable to both FDD and TDD;

fig. 3 shows an embodiment of CQI reliability detection, which is suitable for FDD and TDD;

FIG. 4 is a diagram of the Additive White Gaussian Noise (AWGN) channel HS-SICH results from TDD simulations; and

fig. 5 is a diagram of WG4 test case 2 channel HS-SICH results from TDD simulations.

Detailed Description

As used and described hereinafter, a WTRU includes, but is not limited to, a user device; a mobile station; a fixed or mobile subscriber unit; a pager, or any other type of device capable of operating in a wireless environment. When referred to hereafter, a base station includes, but is not limited to, a node-B; a dot controller; an access point or any type of interfacing device in a wireless environment.

Fig. 1 shows a method 100 for determining the reliability of a CQI and its application to an outer loop power controller in accordance with the present invention. The method 100 begins by initializing a time slot timer and counters, such as total HS-SICHs reception, erroneous HS-SICHs reception, and number of missed HS-SICHs (step 102), the CQI is received (step 104) and decoded (step 106), the two maximum decision route count values are evaluated to determine if they are below a threshold (step 114), and if the difference is below the threshold, the CQI is likely to be erroneous and therefore discarded (step 116).

If the difference meets or exceeds the threshold, then the CQI is assumed to be valid (step 118), next the counter is incremented (step 120) and a determination is made whether the time gap has reached the terminal (step 122), although the flow chart returns to step 104; the loop of steps 104-120 continues to repeat regardless of the value of the counter or whether the time gap has expired.

If the time gap has expired (step 122), a determination is made whether the counter meets or exceeds a threshold (step 124), if the counter is equal to or greater than the threshold, the RNC signals (step 126), the RNC then signals the WTRU to adjust the UL transmit power (step 128), whereupon the method terminates (step 130), if the end of the time gap has not been reached (step 122), or if the counter is below the threshold (step 124), the method also terminates (step 130).

It should be noted that the difference determination in step 112 can also be used when the metric is logarithmic, i.e., decibel, if the metric is purely digital, steps 112 and 114 can be modified as follows. The ratio of the maximum decision metric to the second decision metric is calculated (step 112) and the ratio is compared to the threshold value (step 114).

An approximate alternative is to include additional Iub-sent simple periodic reporting signals, which are the total number of HS-SICHs receptions, the number of erroneous HS-SICHs receptions, and the number of HS-SICHs missed in a fixed time period, and reporting these numbers independent of the error threshold, this type of periodic reporting would add more Iub-sent signals, but would be less complex to implement in node B.

Fig. 2 shows another method 200 for determining the reliability of a CQI and its application for loop power control outside of the present invention. The method 200 begins by initializing counters, such as total HS-SICHs reception, erroneous HS-SICHs reception, and number of missed HS-SICHs (step 202), the CQI is received (step 204) and decoded (step 206), for each symbol in the CQI, a decision metric is calculated (step 208), the two largest decision metrics are selected (step 210), and the difference between the two largest decision metrics is determined (step 212), the difference between the two largest decision metrics is evaluated to determine if it is below a threshold (step 214), if the difference is below the threshold, the CQI is likely to be erroneous and therefore discarded (step 216).

If the difference exceeds the threshold, then the CQI is assumed to be valid (step 218), next the counter is incremented (step 220), and a determination is made whether the time gap has been reached (step 222), although the flow chart returns to step 204; the loop of step 204-220 continues to repeat regardless of the value of the counter.

If the counter is equal to or greater than the threshold, the RNC signals (step 224), the RNC then signals the WTRU to adjust the UL transmit power (step 226), whereupon the method terminates (step 228), and if the counter is less than the threshold (step 22224), the method also terminates (step 228).

When the base station decodes the received 32-bit codeword (steps 106, 206), the output of the decoding process can be considered as one of N error-free hypotheses, where the number of information bits, N, is related to M, which is 2N (N10 in TDD), i.e., one of M symbols is sent by the WTRU to the base station. The hypothesis test at the base station selects the best-fit member of the M-symbol alphabet, which is then converted back to n information bits, representing the symbol, i.e., the code word.

Different decision algorithms exist to decide what is most likely to represent the received symbol, which is a symbol that is usually different from what we know. For example, if it is more likely that a particular signal is sent, incorporating conventional knowledge into the decision algorithm provides an advantage over another algorithm that assumes that all symbols are generally sent identically, and further that, in the FDD context, the decoder can operate as a 32-appropriate filter with one filter for each symbol, where each symbol has a particular waveform (chip/bit sequence), each appropriate filter is associated with the received waveform, which corresponds to a particular symbol, the correlation output from each appropriate filter is essentially a peak corresponding to energy, a very large peak represents "this is likely the sent symbol" (where a code character equals a chip sequence), and a small correlation peak represents "this is unlikely the correct symbol", then, the largest of the 32 acquired peaks is selected and determined to be the sent peak because this is a statistical hypothesis test, and the sign of the determination is, on average, the best determination to be made, an embodiment of this process is shown in FIG. 3. The decoding process at the base station converts the received sequence of channel bits into smooth decision metrics for each symbol that may be outside the M CQI range, which can be implemented on a single integrated circuit or as separate components.

In general, the information bit sequence (the CQI character) is N bits long, and the CQI character is encoded as a one (N, N) Reed-Muller code, which is a bit sequence encoded by M (═ 2N) N bits long. For example, in TDD, with N-10 information bits, which results in 1024 (M-210) possible code words of length N-32 bits, the process of encoding the CQI on the HS-SICH provides samples that plan to convert each of the N code bits into N-4-L channel bits, each of which is spread by a spreading factor of 16 (i.e., a 16 chip long spreading sequence), resulting in L-16-C chips. In TDD, the CQI is usually coded with one (32, 10) Reed-Muller coding, and N is 10, N is 32, L is 128, and C is 2048. Apart from the general dropouts, the principle of the method is equally valid for FDD (16, 5) coding.

As will be appreciated by those skilled in the art, any other type of coding scheme may be used, and the present invention is not limited to the above-described scheme, a (N, N) coding scheme known from channel coding theory, and there are alternative parameters N and N that may be used in the present invention to determine the ratio of its information bits to code the channel bits. For example, a Reed-Muller first or second order code or a Reed-Solomon code may also be used. The particular coding combination of the (N, N) bits involved is not significant as long as the decoder can calculate a discrete decision metric for each symbol and each symbol can be sent on all channels.

Steps 110 and 112 of fig. 1 and steps 210 and 212 of fig. 2 represent one possible method of determining CQI reliability, and many other methods of determining CQI reliability are possible, for example, the ratio of the largest determination metric to the second largest value, or the difference between the two metrics in decibels (10log (ratio)) may also be used. To illustrate with some simple equations, if P_maxRepresents the maximum observed peak value, and P_secondThe ratio (R) can be expressed as R ═ P, indicating the second largest observed peak value_max/P_secondOr log (P)_max)/log(P_second) Or more generally f (P)_max/P_second) And (4) showing. Another proposed method for determining CQI reliability is to determine the ratio of the energy of the largest decision metric to the sum of the energies or weighted sums of the other decision metrics of M-1, e.g., P_i(i-1.. 32) is the peak value observed at the output of the Reed-Muller decoder, P_maxIs namely P_iMaximum value, measured R is represented by R ═ P_max/(∑P_i-P_max)。

By comparing the smoothed decision metrics of the decoded CQI symbols, the base station can use a simple threshold-based decision mechanism to determine whether the received CQI symbol is likely or likely to be error free (steps 114, 214), e.g., if the difference between the largest and second largest metrics is less than 1 db, there is a very high probability (typically greater than 95%) that the CQI is in error and the CQI should be discarded, other differences can be used, but the probability that the corresponding CQI is in error is reduced, a preferred difference range is between 0-2 db, so that the probability that the CQI is in error is sufficiently high.

Taking TDD as an example, the results of one embodiment of the CQI reliability detection method in terms of the ability to detect CQI errors are shown in fig. 4 and 5. The icons of fig. 4 and 5 contain BER after MUD, ACK- > NACK BER, NACK- > ACK BER, discarded CQIs, correct but discarded CQIs, and incorrect but not discarded CQIs, which also contains RMF BER, which is the first bit of a 10-bit length CQI character and indicates the proposed modulation format (either QPSK or QAM). The icon shows the BER of the single bit, the RTBS includes the other nine information bits in the CQI word and indicates the proposed transport block setting, which is the number of information bits in the HS-DSCH transport block that should be sent by the WTRU, and the icon shows the Word Error Rate (WER) of the nine bits indicating that nine RTBS bits have only a few errors.

The following statements can be gathered from fig. 4 and 5: 1) the ACK/NACK plateau decision threshold is 0.1 × signal amplitude; 2) discarding a CQI criterion comprising the highest/second highest correlation peak being less than 1 db in amplitude; 3) erroneous CQIs can be detected immediately; and 4) "the ratio of" correct CQIs wrongly discarded "to" incorrect CQIs not discarded "can be easily scaled to reach the target error value.

Thus, an improved CQI range coding is achieved by the present invention, according to the above method, when the HS-SICH carries ACK/NACK and the CQI is received, there is no means to know if the received HS-SICH range (either the ACK/NACK or the CQI) is received in error because it does not have CRC, if the ACK/NACK is received in error, but the node B does not know this, e.g., the node B may resend a packet that has been successfully received or discarded (not sent) to the WTRU, it should have been sent, waiting for an extended time, the packet will never arrive and the memory will be delayed. The CQI reliability detection according to the present invention allows the node B to indicate which received HS-SICHs is reliable and continue to act properly, like re-transmission, and also, in order to make sure reasonably from time to time (when receiving < 1% of the example) that the HS-SICH is reliable, that the HS-SICH needs to be received at a high SNR value, which means that the WTRU must transmit at a high power, since the WTRU does not have as much power and may have coverage area up to a maximum, the WTRU transmit power must be sufficient to meet the average 0.1 HS-SICH BER, the proposed CQI reliability detection method is provided to the node B by reporting the CQI, tracking the current transmit power setting at the WTRU, and adjusting the power setting.

In addition, the reliability detection method can also be used to provide indicators to the HSDPA base station, and the RNC and CQI reports presented on the HS-SICH/HS-DPCCH to alert the HSDPA base station that the CQI value may be erroneous, as well as to alert the RNC that the delivered SIR may be inadequate via a message from the HSDPA base station over the Iub/Iur network interface. Simple statistics are provided, such as how many received HS-SICHs from a particular WTRU are declared erroneous based on CQI routing metrics, how many total HS-SICHs are received in the same period, and how many HI-SICHs are declared not to need to be sent at all, which functions are usually provided by a CRC, which is now possible because of the CQI reliability test based on a smooth decision router.

According to a specific object of the present invention, new information is added to the Iub/Iur network interface to define the number of transmission failures and the number of symptom-free receptions that occurred, i.e., reporting that a particular WTRU has sent X consecutive UL HS-SICH messages without errors being reported.

Upon a preset number of receptions of the CQI disqualification indicator for a particular WTRU or HS-SICH channel, either the HSDPA base station or the RNC can take appropriate action, such as changing the power control parameters of the WTRU or the HS-SICH channel, or discarding CQIs and using the aforementioned DL HSDPA sent CQI reports. In one embodiment of the present invention (shown in fig. 1), counting is performed in 200 ms time slots, and at most only one HS-SICH is received from a WTRU in each frame (which is 10 ms long), so that at most only 20HS-SICHs is received in 200 ms, and all counters are defined by 0.. 20 (total received HS-SICHs, erroneous HS-SICHs, and missed HS-SICHs).

Although the above examples are directed to HSDPA TDD, the present invention is equally applicable to HSDPA FDD and other transmission formats for improved CQI reliability detection and improved outer loop power control, and although specific embodiments of the present invention have been shown and described, many modifications and changes may be made by those skilled in the art without departing from the scope of the present invention, the above description is intended to be illustrative and not limiting of the invention in any way.

Claims (36)

1. A method for improving reliability of a Channel Quality Indicator (CQI) message in a wireless communication network, comprising:

a) receiving the CQI information;

b) decoding the CQI information;

c) calculating a decision metric for each symbol in the CQI information;

d) determining a maximum decision route metric;

e) determining a second largest decision route metric; and

f) determining the reliability of the CQI information by comparing the values obtained from steps d) and e).

2. The method of claim 1, further comprising the steps of:

g) counting a number of erroneous CQI information received within a time gap;

h) comparing the number of the wrong CQI information with a threshold value when the time gap is over; and

i) if the number of erroneous CQI information exceeds the threshold value, a radio network controller signal is sent to adjust the transmit power of a radio transmit/receive unit that sent the CQI information.

3. The method of claim 1, further comprising the steps of:

g) counting the number of erroneous CQI information received;

h) comparing the number of the wrong CQI information with a threshold value; and

i) if the number of erroneous CQI information exceeds the threshold, sending a radio network controller signal to adjust the transmit power of a wireless transmit/receive unit that sends the CQI information; and

j) if the number of erroneous CQIs does not exceed the threshold value, the method is repeated starting from step a) for the next CQI.

4. The method of claim 1, further comprising the steps of:

g) the CQI information is discarded when the comparison fails to meet a given criterion.

5. The method of claim 4, wherein the criterion in step (g) is whether the difference between the maximum decision metric and the second largest decision metric is less than a predetermined value.

6. The method of claim 5, wherein the default value is between 0 decibels and 2 decibels.

7. The method of claim 5, wherein the default value is less than 1 decibel.

8. The method of claim 4, wherein the criterion in step (g) is whether the difference between the ratio of the second largest decision metric and the largest decision metric is greater than a predetermined value.

9. The method of claim 1, further comprising the steps of:

g) periodically reporting via an Iub message the total number of CQI message receptions, the number of erroneous CQI message receptions, and the number of CQI message dropouts over a fixed time period.

10. A method for improving the reliability of a received message, which indicates the quality of a transmitted channel in a wireless communication system, comprising:

a) receiving Channel Quality Indicator (CQI) information from a Wireless Transmit and Receive Unit (WTRU);

b) decoding the CQI information;

c) obtaining at least two different values, which are CQI information indicative of the decoding; and

d) the at least two values are compared to determine the reliability of the CQI information.

11. The method of claim 10, further comprising the steps of:

e) taking an action based on the result of step (d).

12. The method of claim 11, wherein step (e) comprises providing outer loop power control.

13. The method according to claim 10, wherein step (c) includes obtaining the at least two values as representing a maximum amount of a decision metric and a second maximum amount of the decision metric.

14. The method of claim 13, wherein step (d) comprises calculating the difference between the decision metric having the largest magnitude and the decision metric having the second largest magnitude, in decibels.

15. The method of claim 10, wherein step (d) comprises calculating a ratio of the energy of the decision metric having the greatest magnitude to the sum of the energies of all other decision metrics.

16. A system for determining the quality of a transmission channel in a wireless communication system, comprising:

at least one wireless transmit and receive unit comprising means for generating a Channel Quality Indicator (CQI);

a base station, comprising:

the receiving device is used for receiving the CQI;

decoding means for decoding the CQI;

the calculating device is used for calculating a first decision route metering value and a second decision route metering value of the decoded CQI; and

the comparing device is used for comparing the first and the second decision routing metric values to decide whether the CQI contains an error or not.

17. The system of claim 16 further comprising means for performing an action in response to a specified number of CQI errors received by the base station.

18. The system of claim 17 wherein said actuating means comprises means for providing outer loop power control.

19. The system of claim 16 wherein said means for generating includes means for calculating a downlink sir.

20. The system of claim 16, wherein the first and second decision metrics are a maximum decision metric and a second largest decision metric, respectively.

21. The system of claim 16 wherein said comparing means includes calculating a ratio of said first and second decision metrics.

22. The system of claim 16 wherein said comparing means includes calculating a difference between said first and second decision metrics.

23. A base station for determining the quality of a transmission channel in a wireless communication system, the system comprising at least one wireless transmit and receive unit having generating means for generating a Channel Quality Indicator (CQI), the base station comprising:

the receiving device is used for receiving the CQI;

decoding means for decoding the CQI;

the calculating device is used for calculating a first decision route metering value and a second decision route metering value of the decoded CQI; and

the comparing device is used for comparing the first decision route metering value and the second decision route metering value to decide whether the CQI contains an error or not.

24. The base station of claim 23 further comprising means for performing an action in response to a specified number of CQI errors received by the base station.

25. The base station of claim 24 wherein said means for actuating comprises means for providing outer loop power control.

26. The base station of claim 23 wherein the first and second decision metrics are a maximum decision metric and a second largest decision metric, respectively.

27. The base station of claim 23 wherein said comparing means comprises calculating a ratio of said first and second decision metrics.

28. The base station of claim 23 wherein said comparing means comprises calculating a difference between said first and second decision metrics.

29. An integrated circuit, comprising:

an input configured to receive a Channel Quality Indicator (CQI) information;

decoding means for decoding the CQI information;

the calculating device is used for calculating a first decision route metering value and a second decision route metering value of the decoded CQI; and

the comparing device is used for comparing the first and second decision routing metrics to decide whether the CQI information contains an error.

30. The integrated circuit of claim 29, wherein the first and second decision metrics are a maximum decision metric and a second largest decision metric, respectively.

31. The integrated circuit of claim 29 wherein the comparing means comprises calculating a ratio of the first and second decision metrics.

32. The ic of claim 29 wherein the comparing means comprises calculating a difference between the first and second decision metrics.

33. An integrated circuit, comprising:

an input configured to receive a Channel Quality Indicator (CQI) information;

a Reed-Muller decoder for decoding the CQI information;

a device for calculating decision route metric value is used for calculating a first decision route metric value and a second decision route metric value of the decoded CQI; and

a comparison decision metric device compares the first and second decision metrics to determine whether the CQI information contains an error.

34. The ic of claim 33, wherein the first and second decision metrics are a maximum decision metric and a second largest decision metric, respectively.

35. The integrated circuit of claim 33, wherein the means for comparing decision metrics calculates a ratio of the first and second decision metrics.

36. The integrated circuit of claim 33 wherein the compare decision metric device calculates a difference between the first and second decision metrics.