TW201345166A - Method for measuring sensitivity of data packet signal receiver - Google Patents

Abstract

Methods for measuring the sensitivity of a data packet signal receiver are provided by varying the power level or modulation or both of a received data packet signal in a predetermined controlled sequence of data packet signals.

Description

Sensitivity measurement method of data packet signal receiver

The present invention relates to the acceptable performance of test electronic devices, and more particularly to a plurality of data packet signal receiver sensitivity measurements for a plurality of devices under test.

Electronic receivers are the basic components widely used in mobile phones, wireless personal computers (PCs), and wireless devices. Wireless devices typically must pass an acceptable performance test before leaving the factory. The wireless device test item can include a device receiver sensitivity test. The receiver sensitivity is tested by calculating the packet error rate (PER) of the received packet at the receiver at a known power level. For example, a known number of packets at a predetermined power level are transmitted to the receiver and the number of packets correctly received by the receiver is calculated. The PER algorithm subtracts the number of packets received correctly from the number of packets received (ie, the number of packets received incorrectly) and then divides by the number of packets transmitted, usually expressed as a percentage. For example, the pass score can be less than 10% PER. The preset power level is typically set to a test level that is higher than the receiver's assumed sensitivity. For example, if the sensitivity is assumed to be -75 dBm (absolute power level relative to a decibel of one milliwatt), the selected test level can be -72 dBm. If the receiver receives a packet PER below -10% under -72 dBm power transmission, it passes the test; otherwise the receiver is deemed to have failed the test. If the test level is selected to be equivalent to or very close to the receiver's assumed sensitivity, the receiver may cause a change in the micro-power level due to loose connectors or the like. The test results are inconsistent and inaccurate. Therefore, the test level should normally be chosen to be moderately above the assumed sensitivity to ensure stable test results.

An alternative to the above traditional tests is to find the true or actual sensitivity of the receiver. For example, it may be determined that a series of packets of PER are transmitted at a power level, then a PER of a series of packets transmitted at another power level is determined, and so on until a breakpoint of the PER is found (eg, a point that produces a sudden change). Sensitivity is usually specified when the PER reaches a predefined level, for example, almost the same 10% of the point of change. The power level at which the PER breakpoint occurs can be regarded as the true sensitivity of the receiver, and the receiver is judged whether or not the receiver passes the test based on the found real sensitivity. However, determining the true sensitivity of the receiver may increase the test time because a series of packets must be repeated multiple times at different power levels to find the PER breakpoint. In this case, the receiver test cost may also increase as the test time increases. Even so, it is necessary to determine the true sensitivity of the receiver.

For example, by tracking the true receiver sensitivity of the receiver under test, it is possible to grasp the direction of change in sensitivity level and the rate of change from one receiver to the next. Changes in true sensitivity may be related to the replacement of the receiver component supplier. If the situation of the receiver's sensitivity is found to be deteriorated in time and corrected in time, the trouble of returning the faulty device can be prevented. In addition, modern digital receivers are different from previous analog receivers, and there is usually no problem with a gradual decrease in sensitivity. Significant changes in sensitivity can occur within 1 dB of received power (eg, from testable to untestable). Therefore, in the narrow power range, the true sensitivity breakpoint as a function of power can be a very drastic change. If you don't know where the receiver's true sensitivity is, or in which direction the receiver's true sensitivity changes, when the receiver under test begins to fail, the risk of many receivers failing immediately during production testing becomes high.

In view of this, there is a need to improve on the prior art to determine the true receiver sensitivity of the receiver to be tested in a timely manner (eg, to avoid a substantial increase in test time).

The method of the present invention achieves the purpose of simultaneously measuring the sensitivity of a plurality of data packet signal receivers by varying the power level or modulation or both of a received data packet signal in a predetermined controlled sequence data packet signal.

100‧‧‧ Chart

102‧‧‧Standard Packet Error Rate (PER) Curve Group

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200‧‧‧ method

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502‧‧‧Data Packet Signal (DPS) Receiver

506‧‧‧Vector Signal Generator (VSG)

508‧‧‧Transmission media

510‧‧‧transmitter

512‧‧‧Digital Analog Converter (DAC)

514‧‧‧ memory

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BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be described in detail with reference to the accompanying drawings, wherein like reference numerals are An example of a curve, which can be used to define the sensitivity characteristics of a class of data packet signal receivers; FIG. 2 is a flow chart illustrating an example method for measuring the sensitivity level of a data packet signal receiver according to an embodiment of the invention; The flowchart illustrates an example method for measuring a sensitivity level of a data packet signal receiver according to another embodiment of the present invention. The graph of FIG. 4 illustrates a series of three consecutive data packet signals transmitted according to an embodiment of the invention. The block diagram of FIG. 5 illustrates an example test system for measuring the sensitivity level of a data packet signal receiver according to an embodiment of the invention; FIG. 6 is a diagram illustrating a series of three displays according to an embodiment of the invention. Another example of continuous data packet signal transmission; FIG. 7 is a flowchart illustrating a method for measuring data packet signal according to an embodiment of the invention An example method for the sensitivity level of the receiver; FIG. 8 is a block diagram illustrating an example test system for measuring the sensitivity level of a plurality of data packet signal receivers according to an embodiment of the invention; An embodiment of the invention illustrates an example method for measuring the sensitivity level of each of a plurality of data packet signal receivers.

The present invention provides a method for measuring the sensitivity level of a data packet signal receiver in a device under test (DUT). Generally, the sensitivity characteristic of the data packet signal receiver is defined by a curve showing the packet error rate (PER) as a power level function, and the unit is dBm (absolute power level) or dB (relative power level). The shape or sensitivity characteristics of a curve from one receiver to the next will be roughly the same, but the curve may move to the true sensitivity of the particular unit under test and move left and right along the x-axis (dBm axis). Thus, the true sensitivity level of a particular data packet signal receiver can be described as one of a group of similar curves, and thus can be described as one of a number of groups (eg, many curves) of expected packet error rate (PER) (eg, The relationship between a curve) and the power level of a plurality of data packets.

The graph 100 depicted in FIG. 1 illustrates an example of a standard packet error rate (PER) curve group 102 that can be used to define the sensitivity characteristics of a class of data packet signal receivers. One of the curves, such as curve 104, can describe or define the true sensitivity of the particular data packet to be tested. The example method in the embodiments described herein is used to determine a particular curve, such as curve 104, of the standard PER curve group 102 that best matches or matches the true sensitivity level of a particular data packet to be tested.

For example, three different power levels of data can be packetized (also referred to herein as The data packet or packet is transmitted to the receiver to be tested. This allows the receiver to be tested at three different power levels. For example, three consecutive packets corresponding to -78 dBm, -75 dBm, and -72 dBm can be transmitted to the receiving unit a predetermined number of times. According to the graph 100 of Fig. 1, if the true sensitivity of the receiver to be tested is the curve 104, almost all packets of -78 dBm are lost. It is expected that packets transmitted at approximately 8% at -75 dBm will be lost, and almost all packets of -72 dBm will be received correctly. Assume that 100 data signal packets are received at each of the three power levels. If the true sensitivity of the receiving unit is curve 104, among the 300 transport packets, approximately 192 data packets are expected to be received correctly. For example, all 100 packets transmitted at -72 dBm are expected to be received correctly, 92 out of 100 packets transmitted at -75 dBm are expected to be received correctly, and 100 packets transmitted at -78 dBm are expected to be received correctly. Will not be received correctly. Therefore, the total number of packets that are correctly received in the 300 transmitted packets is 192 packets.

Assume that the receiver sensitivity is shifted down by 1 dB (from -75 dBm to -74 dBm), as indicated by curve 105 in Figure 1. It is expected that approximately 30% of packets transmitted at -75 dBm will be lost (according to curve 105), but the number of packets received or lost by the remaining two levels should be the same as before. Thus, a receiver with a sensitivity of curve 105 can expect to correctly receive about 170 of the 300 outgoing packets. Conversely, if the receiver sensitivity is shifted 1 dB (from -75 dBm to -76 dBm) in the other direction, curve 106 may be close to the true sensitivity of the receiver unit. In this case, the receiver with sensitivity of curve 106 can expect to correctly receive 97 of the 100 packets received at -75 dBm, and it is also possible to correctly receive some packets received at -78 dBm. Therefore, if the true sensitivity level of the receiver unit is modeled by curve 106, it is expected that more than 200 of the 300 transmitted packets will be correctly received.

From the above, a single transmission from a group of data packets with varying power levels The true sensitivity level of a data packet to be tested can be determined. As described above, the total number of correctly received packets can be used to determine the true sensitivity or optimum curve of a particular data packet signal receiver. However, in most cases, it is not necessary to adjust the curve for the determination of the true sensitivity level. Instead, the total number of correctly received packets, such as 100 in 300, can be used to determine whether a particular data packet signal receiver has passed the test. In addition, the total number of packets correctly received by the receiver under test can be tracked to accumulate data and determine the direction and/or rate of change of the sensitivity level of the produced data packet signal receiver. This accumulated data can be used to determine the cause of the change, such as a deterioration in the sensitivity level, which may be caused by changing the supplier of the receiver component.

The flowchart of FIG. 2 depicts an example method 200 for measuring the sensitivity level of a data packet signal receiver in accordance with an embodiment described herein. The sensitivity characteristics of the data packet signal receiver are defined by the relationship between the desired packet error rate (PER) and the plurality of data packet signal power levels by one or more groups (e.g., standard PER curve group 102 of FIG. 1). The method 200 begins at a start block 202 where a plurality of data packet signals are transmitted to a data packet signal receiver. Then proceeding to block 204, comprising receiving the plurality of data packet signals as a first portion and a second portion, corresponding to first and second power levels having power levels of a plurality of data packet signal power levels. Corresponding to the first power level (such as -72 dBm) of the first part is greater than a preset power level (such as -75 dBm), and the second power level corresponding to the second part (such as -78 dBm) is less than the preset power Level. At block 206, the total number of correctly received data packet signals is calculated from the first and second portions. The process proceeds to block 208 where the packet error rate (PER) and the complex number are expected from the one or more groups (e.g., from a plurality of sensitivity curves, such as the standard PER curve group 102 of FIG. 1) based on the total number of correctly received data packet signals. The data encapsulates the relationship between the signal power levels to determine a sensitivity (such as a curve or sensitivity, as shown by curve 104 in Figure 1). At block 210, method 200 provides the determined sensitivity as Test evaluation and sensitivity tracking are used and end here.

In an alternate embodiment, the program of block 208 does not determine a sensitivity or sensitivity curve itself, but rather compares the calculated total number of correctly received data packet signals to a predetermined number. The total number of correctly received data packet signals calculated by this method is closely related to the sensitivity. If the calculated total number of correctly received data packet signals is equal to or greater than the preset number, it means that the data packet signal receiver passes the test; otherwise, the data packet signal receiver is deemed to be unable to pass the test. The total number of correctly received data packets calculated by the receivers is still recorded to track the direction and rate of change of the receiver sensitivity. At block 210, method 200 terminates by determining whether the receiver passes or fails the test.

The determination of a curve or sensitivity in block 208 can be performed, for example, in the following manner. In this example, block 208 includes first selecting a data structure (e.g., a plurality of tables) from a plurality of pre-built data structures. The selection basis includes first and second power levels corresponding to the first and second portions (eg, -72 dBm and -78 dBm), and the number of packets transmitted in each of the first and second portions (eg, in each portion) 100 transmitted packets). The selected pre-built data structure may correlate the total number of correctly received packets with the curve or sensitivity level. Therefore, the total number of correctly received data packet signals can be compared with the selected pre-built data structure (for example, the total can be used as a keyword to perform a lookup in the table data structure) to determine the curve or sensitivity level. For example, the selected pre-built data structure may report or determine the curve 104 of FIG. 1 from the total number of 192 packets correctly received from the 300 transport packets. Alternatively, if 170 packets are correctly received from the 300 transport packets, the selected pre-built data structure may report the curve 105 of FIG. Therefore, the selected pre-built data structure can be used to perform the sensitivity level or sensitivity curve data lookup of the data packet signal receiver based on the total number of correctly received packets.

In an alternate embodiment, data packets of three power levels are transmitted. Data seal The first part of the packet is transmitted at a power level higher than the preset power level (eg -75 dBm) (eg -72 dBm), and the other part is at a power level lower than the preset power level (eg -78 dBm) The transmission is performed while the third portion is transmitted at a level close to or equal to the preset power level. A pre-built data structure (for example, a table data structure) corresponding to the three power levels of the transmitted packet and the respective number of transmitted packets of the three parts may be selected. The total number of correctly received data packet signals is then compared with the selected pre-built data structure (eg, performing a lookup on the table data structure with the total number of keywords) to obtain the available curve or sensitivity level from the selected pre-built data structure. Determine a curve or sensitivity level.

In yet another embodiment, at least two portions of the plurality of data packet signals are received, each portion having a packet of a different power level. Calculate the total number of correctly received packets from at least two parts received. The relationship between one of the one or more sets of expected packet error rates (PER) and the power level of the plurality of data packet signals is then determined based on the total number of correctly received packets. For example, a sensitivity curve is determined from a group of sensitivity curves, such as the standard PER curve group 102 of FIG. 1, as shown by curve 104 of FIG. The determining method is to first select one of the plurality of pre-built data structures based on the data packet signal power level associated with the at least two portions and the respective number of transmission packets in the at least two portions. The total number of correctly received data packet signals can then be compared to the selected pre-built data structure to determine the relationship between one of the one or more sets of desired packet error rates (PER) and the plurality of data packet signal power levels. .

The flowchart of FIG. 3 illustrates an example method 300 for measuring the sensitivity level of a data packet signal receiver in accordance with another embodiment described herein. The sensitivity characteristic of the data packet signal receiver is defined as the relationship between the expected packet error rate (PER) and the power level of the plurality of data packet signals in one or more groups (such as the standard PER curve group 102 of FIG. 1). The method 300 begins at start block 302 where a plurality of data packet signals are transmitted to a data packet signal receiver. Program proceeds to the party At block 304, the plurality of data packet signals are received as first and second portions corresponding to the first and second power levels having a plurality of data packet signal power levels. Corresponding to the first power level (such as -72 dBm) of the first part is greater than a preset power level (such as -75 dBm), and the second power level corresponding to the second part (such as -78 dBm) is less than the preset Power level. In block 306, the first PER and the second PER are calculated based on the first and second portions of the plurality of received data packet signals. The process then proceeds to block 308, which includes comparing the first calculated PER and the second calculated PER with one or more sets of desired PERS counterparts (eg, one or more sensitivity curves, such as the standard PER curve group 102 of FIG. 1). To determine the most suitable or most suitable curve for the first calculated PER and the second calculated PER. For example, using the standard PER curve group 102 of Figure 1, PER can be calculated by transmitting 3% of the portion of the packet with a power level of -76 dBm and 3% of the portion of the packet with a power level of -74 dBm. Or fit the curve 104 of Figure 1. At block 310, method 300 provides the determined sensitivity for test evaluation and sensitivity tracking and ends there.

In an alternate embodiment, data packets of three power levels are transmitted. The first part of the data packet is transmitted at a power level higher than the preset power level (eg -75 dBm) (eg -72 dBm), and the other part is at a power level lower than the preset power level (eg -78 dBm) The transmission, while the third portion is transmitted at a power level that is approximately equal to or equal to the preset power level. Calculate the PER of each of the first, second and third parts. The three calculated PER values are then compared to find out, such as for a fit or optimal fit, a sensitivity curve in a group of sensitivity curves, such as sensitivity curve 104, which may be the most of the standard PER curve group 102 of FIG. Good match.

In yet another embodiment, more than three portions of the data packet having different power levels are transmitted. Calculate the PER of each received part. Then use the three or more PERs for the fit or optimal fit of a sensitivity curve in a group of sensitivity curves, such as the sensitivity curve. 104 may be the best fit in the standard PER curve group 102 of FIG.

Diagram 400 of FIG. 4 illustrates an example transmission sequence 401 that displays three consecutive data packet signals 402, 404, and 406 in accordance with an embodiment as described herein. In this embodiment, each data packet signal has a different power level. For example, the power level 408 of the data packet signal 402 is about -1 dB (relative to a reference power level), the power level 410 of the data packet signal 404 is about +2 dB, and the power level of the data packet signal 406 is 412 is about -4 dB. The sequence 401 can be transmitted a predetermined number of times to provide a plurality of transmission data packet signals for testing the data packet signal receiver. Therefore, the same number of data packet signals can be transmitted at each power level to provide the first portion of the data packet signal at -1 dB, the second portion of the data packet signal at +2 dB, and the data packet signal at -4 dB The third part.

The transmission device should be capable of producing fast and accurate power level changes or continuous packet size changes, as well as short separation times between packets, as shown in the example of FIG. The manner of achieving such a fast and accurate power level change in a continuous packet may be a proportional adjustment of the base frequency representation of the data packet signal to generate a scaled baseband data packet signal. The scaled adjusted baseband data packet signal can then be converted and transmitted. Converting each scaled baseband data packet into a data packet signal, the power level of the data packet signal is associated with the ratio adjustment of the data packet. In this way, a continuous data packet signal with fast and accurate size changes or power level changes can be generated and transmitted. In this case, it is not necessary to use an external attenuator.

For example, the base frequency representation of a data packet signal may be a digital representation of the data packet signal in the digit field. The ratio adjusted baseband data packet signal may be a proportionally adjusted digital data packet signal. The first adjusted digital data packet signal may be generated from the digital representation by multiplying the digital representation by a proportional adjustment factor, such as a scaling factor of 0.5. number. The digital representation can be multiplied by a different scaling factor, such as 0.7, to generate a second adjusted digital data packet signal, or multiplied by another different scaling factor, such as 0.3, to produce a third adjusted digital data. Packet signal. The first adjusted digital data packet signal can be converted to the data packet signal 402 of FIG. 4 by a digital to analog (DAC) converter. The second and third adjusted digital data packet signals may also be converted by the DAC to generate the data packet signals 404 and 406 of FIG. The data packet signals 402, 404, and 406 can be transmitted in the form of radio frequency data packet signals in the radio frequency (RF) domain for receipt by the data packet signal receiver.

The adjusted baseband data packet signal used to generate the plurality of data packet signals for receiver testing may be stored in the memory of the transmission device. The adjusted baseband data packet signal can then be taken out of the memory as needed, and then converted and transmitted. In an alternative embodiment, the adjusted baseband data packet signals corresponding to the data packet signals 402, 404, and 406, such as the first, second, and third adjusted baseband data packet signals, are stored in the transmission device. In memory. When necessary, the pre-stored adjusted baseband data packet signal may be retrieved and repeatedly transmitted for a predetermined preset number to generate the transmission string or a plurality of data packet signals for testing of the receiver to be tested. .

As described above with respect to Figure 4, there may be three parts, each having a different data packet signal power level. In an alternate embodiment, the plurality of data packet signals can comprise two portions, each portion having a different data packet signal power level. The sequence 401 of Figure 4 may include only two packets, each at a different power level, so that after repeated transmissions, two portions are generated. In yet another embodiment, the plurality of data packet signals may also include more than three portions, each portion having a different data packet signal power level. The sequence 401 of Figure 4 can include more than three packets, each at a different power level, so that after repeated transmissions, more than three portions are produced.

The block diagram of FIG. 5 illustrates a test system 500 for measuring the sensitivity level of a data packet signal (DPS) receiver 502 of a device under test 504. The device under test 504 can be a DPS receiver 502, or as shown in FIG. 5, the DPS receiver 502 can be a digital signal processor (DSP) chip, such as an RF chip, that is separate from the device under test 504. Test system 500 has a transmission device, such as a vector signal generator (VSG) 506, for transmitting a plurality of data packet signals for receipt by DPS receiver 502 during its testing. A transmission medium 508 is available to the transmitter 510 of the VSG 506 to transmit a plurality of data packet signals to the DPS receiver 502. Transmission medium 508 may include a wired or wireless connection.

As shown in FIG. 5, the VSG 506 includes a memory 514, a digital analog converter (DAC) 512, and the transmitter 510. The memory 514 can be used to store the adjusted baseband data packet signal 516. The adjusted baseband data packet signal 516 can be retrieved from the memory 514 and provided to the DAC 512 for generating a plurality of data packet signals, as described in relation to FIG. 4 above. For example, the adjusted baseband data packet signal 516 can be an adjusted digital data packet signal for input to the DAC 512 to generate the plurality of data packet signals in the form of transmission information 518 transmitted by the transmitter 510. The subset or the complete adjusted baseband data packet signal 516 can be stored in the memory 514 for generating the plurality of data packet signals. If only a subset is stored, the adjusted subset of the baseband data packet signal 516 is converted to a data packet signal for transmission for a predetermined number of times to generate the plurality of transmission data packet signals.

The DPS receiver 502 may or may not need to establish a link to receive a plurality of transmitted data packet signals. The DPS receiver 502 can be a separate component from the device under test 504, and the device under test 504 can provide a special driver to the DPS receiver 502 to maintain the receiver 502 in a continuous listening mode, awaiting receipt of a test packet sequence.

If the receiver 502 has to establish a link before receiving, the link may be a non-synchronous or synchronous link. Another device not shown in Figure 5 (e.g., a gold card) can generate a link-building packet sequence to the DPS receiver 502 to establish a link. Once the link is established, the gold card switches to VSG 506 for VSG 506 to generate a test packet sequence.

In the case of a connection, the device under test 504 confirms receipt of the packet, but as long as the VSG 506 does not transmit when the device under test 504 sends an acknowledgement, no problem occurs. This can only be easily accomplished by inserting a gap or space between the transmitted packets to allow time to receive confirmation of the previous transport packet. The minimum gap between packets is usually specified in a standard or specification, as specified by the 802.11 standard with 340 microseconds as the minimum interval between packets. Therefore, an 802.11 device under test 504 can be connected and operated by inserting a gap of at least 340 microseconds between the transmission packets. The VSG 506 will directly ignore the acknowledgment of the packet transmission backhaul.

An alternative is to use an external device, such as a gold card, to establish a link to "spoof" the device under test 504 to assume that there is a link inside. The VSG 506 can send an appropriate link to establish a packet sequence to the device under test 504, causing the device under test 504 to assume that the link has been established. For example, the VSG 506 can generate a link-building packet sequence in accordance with the 802.11 standard, allowing the 802.11 device under test 504 to assume that a link has been established. After the transport link establishes the packet sequence, the VSG 506 then generates a test packet sequence and transmits it to the DPS receiver 502.

There are two ways to distinguish between a link-building packet sequence and a test packet sequence. The first method is to suspend or stop the VSG 506 when the number of received packets begins to increase, such as a link setup, to read the correct number of packets received from the device under test 504. A short stop of the VSG 506 does not pose a problem for the asynchronous link, as the way the link is established can ensure that the VSG 506 masters the link. Therefore, the transmission can be stopped briefly from the measured after the link establishment packet sequence transmission Device 504 reads the number of packets received correctly. Therefore, it is possible to adjust the total number of correctly received packets received after the transmission of the test packet sequence by considering the number of correctly received packets received by the connection establishment sequence transmission.

Another method is to deduct the number of correctly received packets from the link establishment transmission of the packet when knowing the number of packets transmitted in the link establishment packet sequence. The connection sequence is established by increasing the power level and the lowest possible bit rate transmission link, and the connection is usually successfully established. After transmitting the test packet sequence, assuming that all devices under test 504 receive correctly, the number of known link establishment packets can be subtracted from the total number of correctly received packets.

A condition requiring a synchronous connection may require more care when suspending the VSG 506 transmission. However, a person with ordinary knowledge in the art can easily determine where to stop and restart the transmission in the link agreement without losing the link. The use of a modern VSG 506 with internal or external trigger signals in the link should easily achieve a short stop transmission and then re-establish the link.

An alternative to transmitting packets at different power levels can also achieve a determination of the true sensitivity level of the data packet signal receiver (eg, based on the calculated PER and the desired PER), or determine the total number of correctly received packets. The purpose of (associated with the true sensitivity level) without significantly increasing the test time. This alternative method transmits a list of test packets at the same power level (so the transmitted packets are unchanged) but is modulated in different ways. This method does not transmit several packet parts with different power levels, but transmits and receives different parts of the packets with different modulations. However, this method requires a system or receiver that supports multiple bit rates, such as the IEEE 802.11 system.

Please note that in this case, "bit rate" can be used instead of "modulation", but the bit rate The purpose of the change in modulation is to seek for changes in sensitivity or SNR. Although lowering the bit rate may increase sensitivity, lowering the bit rate does not necessarily guarantee better sensitivity. The bit rate can be reduced to transfer more power or occupy less bandwidth. It is more appropriate to use the phrase "modulation" than the "bit rate" because the change in modulation does result in a difference in sensitivity.

Diagram 600 of FIG. 6 illustrates an example of another transmission sequence 601 comprised of three consecutive packets 610, 620, and 630, in accordance with an embodiment. In this case, in contrast to FIG. 4, the three consecutive packets 610, 620, and 630 each have substantially the same power level, but are transmitted and received at different bit rates, respectively. For example, although each packet 610, 620, and 630 has the same number of bits, the time interval 640 of the packet 610 transmission is different from the transmission time interval 650 of the packet 620, and the transmission time interval 650 is different from the transmission time interval 660 of the packet 630. . For example, time interval 640 may be associated with 54 Mbps, time interval 650 is associated with 48 Mbps, and time interval 660 is associated with 36 Mbps. The three consecutive packets 610, 620, and 630 have the same power level, but the individual transmission and reception rates are not the same.

Typically, the sensitivity of the DPS receiver 502 (e.g., 10% PER) will correspond to the individual bit rate while maintaining the transmission of packets at the same power level. For example, when the receiver 502 receives a packet transmitted at 54 Mbps, the sensitivity may be -75 dBm. When receiving a packet transmitted at 48 Mbps, the sensitivity may be -78 dBm, and when receiving a packet transmitted at 36 Mbps, the sensitivity may be -80 dBm. If the power level of the transport packet is set to -78 dBm, it is expected to receive most or all packets transmitted at 36 Mbps, packets transmitted at 48 Mbps, and packets transmitted at 54 Mbps. Thus, for example, when a DPS receiver 502 with a sensitivity of -78 dBm receives a packet with a power level of -78 dBm, it is expected to receive all 100 packets transmitted at 36 Mbps, and for 100 packets transmitted at 48 Mbps. Received 90, but not received at 54 Mbps 100 packets transmitted. If the sensitivity of the receiver 502 is -78 dBm, then of the 300 transmitted packets, it is expected that 190 will be received correctly. If the receiver sensitivity 502 is poor, such as -75 dBm, then less than 190 of the 300 transmitted packets are expected to be received correctly. If the receiver sensitivity 502 is better, such as -80 dBm, then more than 190 of the 300 transmitted packets are expected to be received correctly. When testing a plurality of DPS receivers 502, each DPS receiver 502 can collect a total number of correctly received packets from a predetermined number of transmission packets (each portion transmitted at a different data bit rate). The collected data can be used to determine the direction and/or rate of change of sensitivity of the DPS receiver 502 under test. This final result is very similar to the final result from the procedure in Figure 2.

As can be seen from the above, the DPS receiver 502 can receive a group of test packets transmitted at a time, and the test packets are transmitted at the same power level but different bit rates. After being received, the total number of correctly received data packets can be Compared to the preset number. As the above example shows, the total number of correctly received packets is closely related to the true sensitivity of the receiver 502. Therefore, by tracking the total number of correctly received packets, the direction and rate of change of sensitivity of the DPS receiver 502 under test can be tracked.

The flowchart of FIG. 7 illustrates an example method 700 for measuring the sensitivity level of the DPS receiver 502 in accordance with one embodiment described above. At block 702, method 700 begins by transmitting a plurality of data packet signals to DPS receiver 502. Each data packet signal has substantially the same power level, but each is transmitted in one of two different bit rates or portions. At block 704, the DPS receiver 502 receives the transmitted plurality of data packet signals. At least two of the plurality of data packet signals are received, and each of the packets has substantially the same power level. Packets of the same receiving portion are transmitted at the same bit rate, but their bit rate is different from that of another partial packet. At block 706, the total number of correctly received packets is calculated from the plurality of data packet signals received by the DPS receiver 502. At block 708, the total number of correctly received packets is compared to a predetermined number. If the total number of correctly received packets is equal to or greater than the preset number, the DPS receiver 502 passes the sensitivity test, otherwise the sensitivity test is not passed. At block 710, the test results (pass/fail) and the total number of correctly received packets are provided to the tester or user, and the method 700 ends.

In an alternate embodiment, at block 708, the sensitivity of the data packet signal receiver is determined using the total number of correctly received data packet signals. Based on the sensitivity of the decision, the data packet signal receiver may or may not pass the test. At block 710, the sensitivity and/or test results of the data packet signal receiver are reported to the user or tester.

The method 200 of FIG. 2 is more flexible than the method 700 of FIG. 7 because it is related to whether the receiver can receive packets at different bit rates. However, when the test receiver can receive different data bit rates, the advantages of the method 700 can be exploited by replacing the VSG with the communication device to be tested. A communication device can often easily transmit packets at different data rates while maintaining the same power level. For example, a so-called "golden platform" can be used instead of a VSG to generate a packet. The gold platform usually cannot change the output power of each packet one by one, but can easily change the modulation of each packet (such as the data bit rate). Therefore, when testing on a gold platform, it is extremely useful to change the bit rate while maintaining the same power output while transmitting the packet. The reason for the gold platform to get its name is because it usually uses a well-defined device, in this case a transmission or source, and hence the name “Golden Platform”.

It should be understood that the methods of Figures 2 and 7 can also be used in combination. In this way, power changes can be made to individual transmitted packets to achieve the desired spacing. For example, in the above description with respect to Figure 6, to change the portion of the packet received at -80 dBm to receive at -81 dBm, as long as The 36 Mbps signal can be subtracted by 1 dB.

Combining the two methods also meets the need to increase the dynamic test range. For example, suppose a 40 dB SNR is required to ensure that noise in the transmitted signal does not affect the measurement. If the VSG's capability is 60 dB dynamic range, the power can vary from 40 to 60 dB (20 dB range), but for signals such as IEEE 802.1a/g, the average signal peak is 10 dB. Therefore, the VSG can only achieve a fixed RF gain by effectively varying the power over a dynamic range of 10 dB. It can be costly to further increase the dynamic range of the test system (as in terms of power and cost). Combining the two methods of Figure 2 and Figure 7, by increasing the modulation or data bit rate rather than reducing the power, the test sensitivity can be further improved (increasing the dynamic range) without reducing the noise ratio (SNR).

In addition, a combination of the above methods can be used to test the gain step in the RF chip. For example, if the low noise amplifier (LNA) at the front end of the receiver has two different gains, the sensitivity can be tested separately for the high and low gains. This can be achieved with the same signal in the VSG by utilizing a covered packet, for example, in the 20 dB range. If only the power is adjusted, the SNR may be problematic (depending on the VSG), but by combining the modulation and power, it is easy to achieve a 20 dB dynamic range with limited power variation in the test. Naturally, the test level (bit rate of each part) will move because the high gain LNA (best sensitivity) will receive most of the packet levels without loss, and the low gain will only receive a few levels. This is still acceptable as long as the test limits are adjusted. An additional benefit of performing this test with a single packet is that if it takes a long time to adjust the gain of the VSG system, this method can slightly speed up the execution because the gain only needs to be adjusted once.

8 is a block diagram illustrating a test system 800 for measuring sensitivity bits of a plurality of DPS receivers (502a, 502b, and 502c) in a plurality of devices under test (504a, 504b, and 504c), in accordance with another embodiment of the present invention. quasi. The architecture of test system 800 is similar to that described in FIG. However, transmission device 510 is now used to transmit a plurality of data packet signals to a power divider 801 for subsequent reception by the DPS receivers 502 during synchronization testing of a plurality of DPS receivers 502. The transmission of the data packet signals may, for example, employ a single transmission comprising a plurality of data packets having different power levels, bit rates, and/or modulations. As will be appreciated by those skilled in the art, any other component or combination of components capable of assigning signals received from VSG 506 to each of the DPS receivers 502 can be used in place of power splitter 801 as long as each DPS receiver 502 signal is known. The power level of the transmission can be. In a preferred embodiment, DPS receiver 502 receives transmissions from power splitter 801 at the same power level. However, in an alternate embodiment, each DPS receiver 502 may receive transmissions at different (but known) power levels. A transmission medium 508 can transmit the plurality of data packet signals from the transmitter 510 of the VSG 506 to the power splitter 801. Similarly, transmission medium 803 can be used to transmit the data packet signals from power splitter 801 to respective DPS receivers 502. These transmission media 508, 803 may include wired or wireless connections and may not be identical. For example, transmission media 508 and 803a may use wired connections, while transmission media 803b and 803c may use wireless connections. In another embodiment of the invention, the transmitter 510 of the VSG 506 may directly transmit the transmission of a plurality of data packet signals to each of the DPS receivers 502. The change in transmission power between each of the transmission media 508, 803 and the power splitter 801 is known or can be quickly determined. Accordingly, the power level of the transmission received by each DPS receiver 502 is known. The VSG 506 can generate a plurality of packets of a predetermined power level and receive the signals simultaneously (or substantially simultaneously) by the DPS receivers 802. Therefore, according to the above embodiment, the signal characteristics (such as power level, bit rate, and/or modulation) of the transmission received by each DPS receiver can be utilized to simultaneously determine the sensitivity level of the plurality of DPS receivers. The advantage of performing synchronous or parallel testing in this manner is that the test time required to test a plurality of DPS receivers can be reduced.

9 is a flow chart illustrating a method 900 for simultaneously measuring sensitivity levels of a plurality of data packet signal receivers, as described in one embodiment herein. Each of the plurality of data packet signal receivers (e.g., each of the DPS receivers 502a, 502b, and 502c of FIG. 8) has a sensitivity characteristic defined as one or more groups (such as the standard PER curve group 102 of FIG. 1) desired packet. The relationship between the error rate (PER) and the power level of a plurality of data packet signals. The method 900 begins at block 902 where a plurality of data packet signals are simultaneously transmitted to each data packet signal receiver. The process proceeds to block 904, which includes receiving, by each DPS receiver, the plurality of data packet signals as a first portion and a second portion, the two portions corresponding to the first and second powers of the plurality of data packet signal power levels Level. The first power level corresponding to the first part (eg -72 dBm) is greater than a preset power level (eg -75 dBm), and the second power level corresponding to the second part (eg -78 dBm) is less than the preset Power level. At block 906, a total number of data packet signals correctly received by the DPS receiver from the first and second portions is calculated. The process proceeds to block 908 where a packet error rate (PER) and a complex number are expected from the one or more groups (e.g., from a plurality of sensitivity curves, such as the standard PER curve group 102 of FIG. 1) based on the total number of correctly received data packet signals. The relationship between the power levels of the data packet signals determines the sensitivity of each DPS receiver (such as a curve or sensitivity, as shown by curve 104 in Figure 1). Again, in a preferred embodiment, this determination is made in parallel, with each DPS receiver being substantially simultaneously performed. Alternatively, this determination may be made in succession (e.g., to reduce the time required to perform the decision at the expense of increasing the time required to test all DPS receivers). At block 910, method 900 ends where the determination sensitivity of each DPS receiver is provided for test evaluation and sensitivity tracking.

In an alternate embodiment, the program of block 908 does not determine the sensitivity or sensitivity curve of each DPS receiver itself, but rather compares the total number of correctly received data packet signals counted by each DPS receiver with a predetermined number. Correct receiving data packet calculated according to the method The total number of signals is closely related to sensitivity. If the calculated total number of correctly received data packet signals is equal to or greater than the preset number, the data packet signal receiver passes the test; otherwise, the data packet signal receiver is deemed to have failed the test. Track the total number of received data packets correctly by the receiver under test to track the direction and rate of change of receiver sensitivity. Similarly, the total number of correctly received data packets can be compared with the DPS receivers (eg, DPS receivers 502a and 852b of FIG. 8) to determine the receiver sensitivity change direction and rate of change. At block 910, method 900 ends by determining if each receiver passed the test.

As can be seen from the above, the test system 800 can be used in combination with any of the above embodiments, as shown in FIG. 8, so that a plurality of DPS receivers can simultaneously measure a single transmission of a plurality of data packet signals, wherein the plurality of data packet signals are variable. Power level, bit rate and/or modulation. Each of the tested DPS receivers 502 receives this single transmission. The total number of packets correctly received by each DPS receiver (e.g., 502a, 502b, and 502c) is determined and used to individually determine the sensitivity level of each DPS receiver. This greatly reduces test time because it can be tested simultaneously regardless of the number of DPS receivers. Alternatively, the first transmission of the plurality of data packet signals may be sent to a first DPS receiver (eg, DPS receiver 502a of FIG. 8) or a first group of DPS receivers (eg, DPS receivers 502a and 502b of FIG. 8) ). The second transmission of the plurality of data packet signals is then sent to a second DPS receiver (e.g., DPS receiver 502c of FIG. 8) or a second group of receivers. The transmission of the second signal may be sent when the sensitivity level of the first DPS receiver or the first group of DPS receivers is determined or sent when a new receiver or group of receivers is set, such as via a test operator. In this way, in the case that the time required for setting the device is close to the time required for each test, the near-repetition test of the DPS receiver can be achieved, further shortening the required test time.

Among the many advantages, embodiments as described herein are available for determining one or more funds to be tested. The true sensitivity level of the packet signal receiver, or the total number of correctly received packets associated with the true sensitivity level, does not significantly increase the test time. In addition, the true sensitivity data of the signal receiver of the measured data packet, whether it is the best matching sensitivity curve or the total number of correctly received packets, can be cumulatively tracked for later analysis. For example, by knowing the trend or direction of sensitivity change, such as deterioration or improving sensitivity, the cause of this trend can be found, such as the trend may be related to the replacement of the receiver component supplier.

The above detailed description of the present invention and the examples described herein are merely illustrative and not intended to be limiting. For example, the operation can be done by any suitable method. Method steps can be performed in any suitable order to provide the described operations and results. It is intended that the present invention covers all modifications and changes and equivalents in the spirit and scope of the invention.

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Claims (22)

A method for measuring respective sensitivity levels of a first and a second data packet signal (DPS) receiver, wherein the sensitivity level of each sensitivity level is based on a desired packet error rate (PER) and a data packet signal Defining a relationship between power levels, the method comprising: receiving, by the first DPS receiver and the second DPS receiver, a single transmission of a data packet signal, the data packet signal comprising a group of data packets, wherein the plurality of data packets The first and second portions of the data packet signal respectively have first and second data packet signal power levels, and the first and second data packet signal power levels are respectively greater than or less than a predetermined power level; Calculating, by the first DPS receiver, a first accumulated number of one of the data packet signals correctly received by the first DPS receiver from the first and second portions of the received plurality of data packet signals; at least in part The second DPS receiver calculates one of the data packet signals correctly received by the second DPS receiver from the first and second portions of the received plurality of data packet signals a second accumulated number; and after receiving all of the group data packets, including the first and second accumulated numbers of the correctly received data packet, determining one of the first DPS receivers based on the first accumulated number of the correctly received data packet signal A first single desired PER, and a second single expected PER of the second DPS receiver based on the second accumulated number of the correctly received data packet signal. The method of claim 1, wherein the determining comprises: selecting one of a plurality of pre-built data structures; and respectively selecting the first and second accumulated numbers of the correctly received data packet signal with the selected plurality of pre- Comparing one of the data structures to determine the first and second single expected PERs The relationship between the signal level and the power level of the data packet. The method of claim 1, further comprising: receiving a third portion of the plurality of data packet signals having a third data packet signal power level substantially equal to the predetermined power level; And calculating, by the first, second, and third portions of the plurality of data packet signals, the first and second accumulated digits of the correctly received data packet signal. The method of claim 3, wherein the determining comprises: selecting one of a plurality of pre-built data structures; and respectively selecting the first and second accumulated numbers of the correctly received data packet signal with the selected plurality of pre- One of the data structures is compared to determine the relationship between the first and second single expected PERs and the power level of the data packet signal. The method of claim 1, wherein one or more of the receiving, calculating, and determining of the first DPS receiver and the second DPS receiver are performed substantially simultaneously. A method for measuring respective sensitivity levels of a first and a second data packet signal (DPS) receiver, wherein the sensitivity level of each sensitivity level is based on a desired packet error rate (PER) and a data packet signal Defining a relationship between power levels, the method comprising: receiving, by the first DPS receiver and the second DPS receiver, a single transmission of a data packet signal, the data packet signal comprising a group of data packets, wherein the group At least two portions of the data packet each have different data packet signal power levels; and at least partially the first DPS receiver calculates the correctly received data from the first DPS receiver from at least two portions of the received data packet. a first accumulated number of packets; at least partially at least two of the received packet data packets from the second DPS receiver And calculating a second accumulated number of the data packet correctly received by the second DPS receiver; and receiving all the group data packets, including the first and second accumulated numbers of the correctly received data packet, based on the correct receiving A first accumulated number of data packets determines a first single expected PER of the first DPS receiver, and a second single expected PER of the second DPS receiver is determined based on the second accumulated number of the correctly received data packets. The method of claim 6, wherein the determining comprises: selecting one of a plurality of pre-built data structures; and separately pre-establishing the first and second accumulated numbers of the correctly received data packet with the selected plurality of pre-built One of the data structures is compared to determine the relationship between the first and second single expected PERs and the data packet signal power level. The method of claim 6, further comprising transmitting the data packet signal. The method of claim 8, wherein the baseband representation of the data packet signal is scaled to generate the adjusted baseband data packet, and the adjusted baseband data packet is converted and transmitted as At least two parts of the group data packet are transmitted. The method of claim 9, wherein the fundamental frequency representation of the data packet signal is a digit representation, the adjusted baseband data packet is an adjusted digital data packet, and the adjusted digital data packet is Converted by a digital analog converter (DAC). The method of claim 9, wherein the adjusted baseband data packet is stored in a memory for later retrieval for use in the converting and transmitting. The method of claim 11, wherein the stored adjusted baseband data packet is converted and repeatedly transmitted a predetermined number of times to generate at least two portions of the group of data packets that are transmitted. The method of claim 6, wherein one or more of the receiving, calculating, and determining of the first DPS receiver and the second DPS receiver are performed substantially simultaneously. A method for measuring respective sensitivity levels of a first and a second data packet signal (DPS) receiver, each sensitivity level sensitivity characteristic being based on a desired packet error rate (PER) and a correlation bit Defining a relationship between one of the data rate modulation signal power levels, the method comprising: receiving, by the first DPS receiver and the second DPS receiver, a single transmission of a data packet signal, the data packet The signal includes a group of data packets, wherein the first and second portions of the group of data packets have substantially equal data packet power levels and corresponding to the first and second bit rate modulations, the first and second bits The rate modulation is greater than or less than a preset bit rate modulation; at least in part, the first DPS receiver calculates the correctness of the first DPS receiver from the received first and second portions of the group data packet. Receiving a first accumulated number of the data packet; at least partially calculating, by the second DPS receiver, the first and second portions of the received data packet to calculate a correct receipt of the data packet by the second DPS receiver two And accumulating the number; and after receiving all the data packet, including the first and second accumulated numbers of the correctly received data packet, determining a first single of the first DPS receiver based on the first accumulated number of the correctly received data packet The PER is expected, and a second single expected PER of the second DPS receiver is determined based on the second accumulated number of the correctly received data packet. The method of claim 14, further comprising: receiving a third portion of the group data packet, the third portion having a data packet, The power level of the data packet is substantially equal to the power level of the data packet in the first and second portions, and the third portion has a third bit rate modulation substantially equal to the preset bit rate modulation; And calculating, by the first, second, and third portions of the received data packet, the first and second accumulated digits of the correctly received data packet. The method of claim 14, wherein one or more of the receiving, calculating, and determining of the first DPS receiver and the second DPS receiver are performed substantially simultaneously. A method for measuring respective sensitivity levels of a first and a second data packet signal (DPS) receiver, each sensitivity level sensitivity characteristic being based on a desired packet error rate (PER) and a correlation bit Defining a relationship between one of the data rate modulation signal power levels, the method comprising: receiving, by the first DPS receiver and the second DPS receiver, a single transmission of a data packet signal, the data packet The signal includes a group of data packets, wherein at least two portions of the group of data packets have substantially equal power levels, and the at least two portions each have different bit rate modulation; at least partially received by the first DPS receiver At least two parts of the group, calculating a first accumulated number of the data packet correctly received by the first DPS receiver; calculating, at least in part, the second DPS receiver from the received at least two parts of the group a second accumulated number of the data packet correctly received by the second DPS receiver; and after receiving all the data packet, including the first and second accumulated numbers of the correctly received data packet, Determining a first single expected PER of the first DPS receiver based on the first accumulated number of the correctly received data packet, and second reliance based on the correctly received data packet A second number is used to determine a second single desired PER of the second DPS receiver. The method of claim 17, wherein at least one of the at least two portions has a bit rate modulation lower than a predetermined bit rate modulation, and at least one of the at least two portions has a A bit rate modulation that is higher than the preset bit rate modulation. The method of claim 17, wherein one or more of the receiving, calculating, and determining of the first DPS receiver and the second DPS receiver are performed substantially simultaneously. A method for measuring respective sensitivity levels of a first and a second data packet signal (DPS) receiver, each sensitivity level sensitivity characteristic being based on a desired packet error rate (PER) and a correlation bit Defining a relationship between one of the data rate modulation signal power levels, the method comprising: receiving, by the first DPS receiver and the second DPS receiver, a single transmission of a data packet signal, the data The packet signal includes a group of data packets, wherein at least two portions of the group data packet have substantially the same power level and bit rate modulation, and at least two other portions of the group data packet have different power levels and bit rate adjustments. Converting, by the first DPS receiver, at least in part, from the received at least two portions of the group, a first accumulated number of data packets correctly received by the first DPS receiver; at least in part by the second DPS receiver Calculating, from at least two parts of the received group, a second accumulated number of the data packet correctly received by the second DPS receiver; and receiving all the group data packets, including the correct connection And receiving, by the first and second accumulated digits of the data packet, determining a first single expected PER of the first DPS receiver based on the first accumulated number of the correctly received data packet, and a second accumulated number based on the correctly received data packet A second single desired PER of the second DPS receiver is determined. The method of claim 20, wherein at least one of the at least two portions has a bit rate modulation lower than a preset bit rate modulation and a power level lower than a predetermined power level And at least one of the at least two parts has a bit rate modulation higher than the preset bit rate modulation and a power level higher than the preset power level. The method of claim 20, wherein one or more of the receiving, calculating, and determining of the first DPS receiver and the second DPS receiver are performed substantially simultaneously.