Demodulation of ARQ Channel Measurement Description

Demodulation of ARQ Channel Description

The Demodulation of ARQ Channel Measurement is used to verify the Access Terminal's demodulation performance of the ARQ channel in AWGN conditions. This measurement is only applicable to the Access Terminal (AT) which supports Subtype 2 Physical Layer. See Release A Physical Layer Subtype to configure the physical layer subtype.

The measurement has two phases: NAK test and ACK test. During the test, the test set sends NAK bits on the ARQ channel in NAK test first, then sends ACK bits on the ARQ channel in ACK test. The AT demodulates the ARQ channel and sends the corresponding R-Data sub-packets according to the ARQ bits. Then the test set bases on the sub-packet ID which is decoded from RRI channel to judge if the AT correctly demodulates the NAK/ACK bits sent on the ARQ channel. NAK test calculates the error rate P(ACK/NAK) which is the ratio, in percent, of the number of NAK bits on the ARQ channel misunderstood by the AT as ACK bits to the number of NAK bits sent on the ARQ channel. ACK test calculates the error rate P(NAK/ACK) which is the ratio, in percent, of the number of ACK bits on the ARQ channel misunderstood by the AT as NAK bits to the number of ACK bits sent on the ARQ channel. The measurement also calculates and returns the Confidence Limit and Confidence Level for NAK test and ACK test.

Confidence Limit Testing

In Demodulation of ARQ Channel measurement, the confidence limit is specified as a combined limit of P(NAK/ACK) and P(ACK/NAK). 3GPP2 C.S0033-A section 3.2.6.3 specifies that the combination of P(NAK/ACK) and P(ACK/NAK) for each test should not exceed the piece-wise linear curve in a log-log domain where the x-axis corresponds to P(ACK/NAK) and the y-axis corresponds to P(NAK/ACK) specified by points in the corresponding table in Minimum Standard for ARQ Channel Demodulation Performance in AWGN .

P(ACK/NAK) limit and P(NAK/ACK) limit are determined separately from the measured value as shown in figures below. The curve in red is against the limits for Bi-Polar Keying (BPK) H-ARQ Modulation type and the curve in blue is against limits for On-Off Keying (OOK) H-ARQ Modulation type.

P(ACK/NAK) limit is determined by linearly interpolate the extended minimum specification with the measured P(NAK/ACK) as shown in the figure: The Confidence Limit for NAK Test. P(NAK/ACK) limit is determined in similar way by linearly interpolate the extended minimum specification with the measured P(ACK/NAK), as shown in the figure: The Confidence Limit for ACK Test.

Minimum Standard for ARQ Channel Demodulation Performance in AWGN

Test	P(NAK/ACK)	P(ACK/NAK)
1	3.2E-3	3.0E-5
	5.0E-4	3.0E-4
	3.0E-5	3.2E-3
2	1.3E-2	2.0E-5
	1.7E-3	2.0E-4
	1.1E-4	2.0E-3

Demodulation of ARQ Channel Parameters

• Maximum NAK Count - Sets the maximum number of NAK bits to be sent on the ARQ channel during the demodulation of ARQ channel measurement (range is 1,500 to 10,000,000 bits).
• Maximum ACK Count - Sets the maximum number of ACK bits to be sent on the ARQ channel during the demodulation of ARQ channel measurement (range is 1,500 to 10,000,000 bits).
• H-ARQ Modulation - (See H-ARQ Modulation ).
• H-ARQ/L-ARQ Channel Level - (See H-ARQ/L-ARQ Channel Level ).
• Trigger Arm - (See Trigger Arm (Single or Continuous) Description ).
• Timeout Time/State - Range is 0.1 to 266,667.0 seconds. (See Measurement Timeouts ).

Demodulation of ARQ Channel Results

• Integrity Indicator - (See Integrity Indicator ).
• Probability - ratio, in percent, of the bits misunderstood by the AT to the number of bits tested.
• Error Count - number of bits misunderstood by the AT.
• Tested Count - number of bits tested.
• Confidence Limit - (See Confidence Limit Testing ).
• Confidence Level - (See Confidence Level Testing ).

Intermediate measurement results are periodically available on the front panel display, but are not available programmatically through the GPIB interface.

A typical display is shown below: