MX2007013642A - 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

METHOD FOR MEASURING SENSITIVITY OF DATA PACKET SIGNAL RECEIVER FIELD OF THE INVENTION The present invention relates generally to the testing of electronic equipment for acceptable performance and more particularly, to the measurement of the sensitivity of a data packet signal receiver of a device under test (DUT, for its acronym in English).

BACKGROUND OF THE INVENTION An electronic receiver forms a basic component in mobile cell phones, wireless personal computers (PCs), and wireless devices in general. Typically, a wireless device is tested for acceptable performance before leaving the production facility. Part of the wireless device test may include testing the sensitivity of a device receiver. The sensitivity of the receiver can be tested by calculating a packet error rate (PER) for packets received by the receiver at a given power level. For example, a known number of packets at a predetermined power level are transmitted to the receiver and the number of packets received correctly by the receiver is calculated. The PER is the number of packets transmitted minus the number of packets received correctly (ie, the number of packets that are not received correctly) divided by the number of packets transmitted, usually expressed as a percentage. A step classification, for example, can be a PER of 10% or less. The predetermined power level is normally chosen at a test level higher than the assumed sensitivity of the receiver. For example, if the assumed sensitivity is -75 dBm (decibels in relation to one milliwat, and therefore an absolute power level), the chosen test level can be -72 dBm. If the PER of a receiver is 10% or less for received packets transmitted at a power of -72 dBm, the receiver passes; also the receiver fails the test. If the test level is chosen at or nearly close to the assumed sensitivity of the receiver, then a small variation in the power level at the receiver, eg, due to a loose connector, etc., may result in test results. approved / not approved variable and inconsistent. Therefore, the test level is normally chosen at a point suitably higher than the assumed sensitivity to ensure a stable test result. An alternative to the traditional test described above is to investigate the true or actual sensitivity of the receiver. For example, the PER could be determined for a sequence of packets transmitted at a power level and then a packet sequence transmitted at another power level and continuing in this way up to a break point (eg, a power point). abrupt change) is in PER. Sensitivity is usually specified when PER reaches a predefined level of, for example, 10% which is usually almost the same as the abrupt change point. The power level at which the PER breakpoint occurs can be chosen as the actual sensitivity of the receiver and, based on the actual sensitivity found, approves or disapproves the receiver. However, determining the actual sensitivity of the receiver can increase the test time as a number of interactions of a packet sequence may have to be transmitted at varying power levels before finding the breakpoint of PER. In this case, the cost of testing for an acceptable receiver may develop as the testing time increases. Even so, determining the sensitivity of the real receiver can be very convenient. For example, by tracking the receiver's actual sensitivity for receivers under test, the direction of change in sensitivity level from one receiver to the next, as well as the rate of change, may be known. A change in sensitivity can be correlated to a change in providers for a receiver component. A deteriorating receiver sensitivity, if found and corrected in time, can prevent the return of devices not approved for the network. In addition, modern digital receivers, unlike analogue predecessors, do not normally degrade sensitivity gradually. A large change in sensitivity (eg, passing a test to fail a test) can occur within 1 dB of received power. Therefore, the actual sensitivity breakpoint as a power function can be a very sharp change in a narrow range of power. Without knowing where the receiver's real sensitivity is, or in which direction the receiver's actual sensitivity is changing, when the receivers under test are not approved, the risk is high since many receivers will fail once during the production test. In view of the above, improvements are required to determine in a timely manner (eg, so as not to significantly increase the test time) the actual sensitivity of the receiver for a receiver under test.

SUMMARY OF THE INVENTION Methods are provided for measuring the sensitivity of a data packet signal receiver by varying the power level or modulation or both for a packet signal of data received in a predetermined controlled sequence of data packet signals. In one embodiment, a method for measuring a sensitivity level of a data packet signal receiver having a characteristic sensitivity defined by an expected data packet error rate (PER) against a packet signal power level is provided. data, comprising: receiving first and second portions of a plurality of data packet signals having correspondingly first and second data packet signal power levels that are greater than, and less than, respectively, a predetermined power level; calculating from said first and second received portions of a plurality of data packet signals a total number of data packet signals received correctly; and determining, based on the total number of data packet signals received correctly, said expected PER against said signal power level of data packets. In another embodiment, a method for measuring a sensitivity level of a data packet signal receiver having a characteristic sensitivity defined by a packet error rate (PER) expected against a power level is provided. Signal of data packets, included; receive at least two portions of a plurality of data packet signals, each of at least two portions having a different packet signal strength level; calculating, from said at least two received portions of a plurality of data packet signals a total number of data packet signals received correctly; and determining, based on the total number of data packet signals received correctly, said expected (PER) against said signal power level of data packets. In yet another embodiment, a method is provided for measuring a sensitivity level of a data packet signal receiver having a characteristic sensitivity defined by an expected packet error rate (PER) against a packet signal power level of data, comprising: receiving first and second portions of a plurality of data packet signals having correspondingly first and second power levels of data packet signals that are greater than and less than, respectively, a predetermined power level; calculating first and second PER corresponding to said first and second portions of the plurality of received data packet signals, respectively; and comparing said first and second calculated PER to said expected PER. In another embodiment, a method for measuring a sensitivity level of a packet signal receiver is provided of data having a characteristic sensitivity defined by an expected packet error rate (PER) against a signal power level of data packets comprising: receiving at least two portions of a plurality of data packet signals; each of at least two portions having a different data packet signal strength level; calculating a PER for each of at least two portions of a plurality of data packet signals; and comparing the PER calculated for at least two portions to said expected PER. In yet another embodiment, a method is provided for measuring a sensitivity level of a data packet signal receiver having a characteristic sensitivity defined by an expected packet error rate (PER) against a packet signal power level of data to an associated modulation, comprising: receiving first and second portions of a plurality of data packet signals having signal power levels of substantially equal data packets and correspondingly first and second modulations that are greater than and less than, respectively, a predetermined modulation; calculating from said first and second portions of a plurality of data packet signals a total number of data packet signals received correctly; and determining, based on the total number of data packet signals received, said expected PER. In one embodiment, a method is provided for measuring a sensitivity level of a data packet signal receiver having a sensitivity characteristic defined by an expected packet error rate (PER) against a packet signal power level of data in an associated modulation, comprising: receiving at least two portions of a plurality of data packet signals, said at least two portions having data packet signals with substantially equal power levels and each of at least two portions having different modulations; calculating said at least two received portions a total number of data packet signals received correctly; and determining, based on the total number of data packet signals received correctly, said expected PER. In another embodiment, a method is provided for measuring a sensitivity level of a data packet signal receiver having a sensitivity characteristic defined by an expected packet error rate (PER) against a packet signal strength level of data in an associated modulation, comprising: receiving at least two portions of a plurality of data packet signals, the data packet signals of a portion of minus two portions having substantially the same power and modulation level, and the power and modulation level differing between the portions of at least two portions; calculating from said at least two received portions, a total number of data packet signals received correctly; and determining, based on the total number of data packet signals received correctly, said expected PER.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be more easily understood in view of the following description when accompanied by the following figures and where the reference numbers represent similar elements: Fig. 1 illustrates a graph showing an example of a group of error rate curves packet (PER) normal that can be used to define the sensitivity characteristic of a type of data packet receiver; Fig. 2 illustrates a flow chart describing an example of a whole for measuring a sensitivity level of a data packet signal receiver according to an embodiment of the invention; Fig. 3 illustrates a flow chart describing an example of a method for measuring a sensitivity level of a data packet signal receiver according to another embodiment of the invention: Fig. 4 illustrates a graph showing a example of a transmitted sequence of three consecutive data packet signals according to one embodiment of the invention; Fig. 5 illustrates a block diagram of an example of the test system configured to measure a sensitivity level of a data packet signal receiver according to an embodiment of the invention; Fig. 6 illustrates a graph showing an example of yet another transmitted sequence of three consecutive data packet signals according to one embodiment of the invention: Fig. 7 illustrates a flow chart describing an example of a method for measuring a sensitivity level of a data packet signal receiver according to an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION A method is provided for measuring a sensitivity level of a data packet signal receiver in a device under test (DUT, for its acronym in English). Normally, a data packet signal receiver has a sensitivity characteristic defined by a curve that shows the packet error rate (PER) as a function of the power level measured in dBm (absolute power level) or dB (level relative power = The shape of the curve or sensitivity characteristic remains around it from one receiver to the next of the same type, except that the curve can move to the left or right along the x axis (dBm axis) corresponds to the movement in the real sensitivity of a particular unit under test.Therefore, the actual sensitivity level of a particular data packet signal receiver can be described as one of a group of similar curves, and therefore as one (e.g., a curve) of many pluralities (eg, of many curves) of packet error rates (PER) expected against a plurality of data packet signal power levels. g.1 illustrates a graph 100 showing an example of a group of normal packet error rate (PER) curves 102 that can be used to define the sensitivity characteristic of a type of data packet receiver. One of the curves, eg, curve 104, may describe, or define the actual sensitivity of a particular low data packet signal receiver proof. The present embodiments exemplify methods for determining the particular curve, e.g. curve 104, of the group of normal PER curves 102, which are equal or better equal to the actual sensitivity level for a particular data packet signal receiver under test. For example, data packet signals (also referred to herein only as packets of data or packets) at three different power levels can be transmitted to the receiver under test. By doing this, the receiver will be tested at three different power levels. For example, three consecutive data packets can be transmitted corresponding to -78 dBm, -75 dBm, and -72 dBm a predetermined number of times to the receiving unit. According to the graph 100 of Fig. 1, almost all packages at -78 dBm are expected to be lost if the actual sensitivity of the receiver under test is curve 104. Approximately 8% of the packets transmitted at -75 dBm it is expected to be lost and almost all packages at -72 cBm should be received correctly. It is assumed that 100 packets of data signals from each of the three power levels are received. Of the 300 packets transmitted, about 192 data packets could be expected to be received correctly if the receiving unit has a real sensitivity described by the curve 104. For example, all 100 packets transmitted at -72 dBm could expected to be received correctly, 92 of the 100 packets transmitted at -75 dBm could be expected to be received correctly and none of the 100 packets transmitted at -78 dBm could be expected to be received correctly. Therefore, the sum of correctly received packets could be 192 packets of the 300 transmitted packets. However, it is assumed that the sensitivity of the receiver changes 1 dB lower (from -75 dBm to -74 dBm) and is represented by a curve 105 of the Dig. 1. The expectation could be that approximately 30% of the packets transmitted at -75 dBm could be lost (according to curve 105), but the remaining two levels could result in the same number of lost packets received as before. Therefore, the receiver with a sensitivity of the curve 105 could be expected to receive approximately 170 packets correctly from the 300 transmitted packets. In contrast, if the sensitivity of the receiver changes to another direction by one dB (from -75 dBm to -76 dBm), a curve 106 can approximate the actual sensitivity of the receiving unit. In this case, the receiver with a sensitivity of the curve 106 could be expected to correctly receive 97 of the 100 received packets at -75 dBm, and a few of the received packets at -78 dBm can also be received correctly. Therefore, you are expected to receive correctly more than 200 packets of the 300 transmitted packs if the actual sensitivity level of the receiving unit is modeled by the curve 106. It should be understood from the above that the actual sensitivity level can be determined for a packet signal receiver of data under test of a single transmission of a group of data packets with variable power levels. As exemplified above, the total number of correctly received packets can be used to determine the actual sensitivity or best fit curve for a particular data packet signal receiver. However, even in most cases a curve adjustment for the actual sensitivity level determination by itself, may not need to be performed, but the total number of correctly received packets, eg, 100 of 300, could be used. to determine an approved / unapproved test result for a particular data packet signal receiver. Additionally, the total number of correctly received packets could be tracked for receivers under test to accumulate data in order to determine the change direction and / or rate of change in the sensitivity level for the data packet signal receivers produced. These accumulated data can be used to determine the causes of changes, eg, a worse level of Sensitivity can be related to a change in supplies of a receiver component. Fig. 2 illustrates a flow chart describing an example of a method 200 for measuring a sensitivity level of data packet signal receiver according to a mode described herein. The data packet signal receiver has a sensitivity characteristic defined by one or more pluralities (e.g., the group of normal PER curves 102 of FIG. 1) of the expected packet error rates (PER) against a plurality of power levels of data packet signals. The method 200 starts at the starting block 202 with the transmission of a plurality of data packet signals to a data packet receiver. Processing proceeds to block 204 which includes receiving the plurality of data packet signals as first and second portions having correspondingly first and second power levels of a plurality of data packet signal power levels. The first power level (eg, -72 dBm), corresponding to the first portion, is greater than a predetermined power level (eg, -75 dBm), and the second power level (v. gr., -78 dBm), corresponding to the second portion, is less than the predetermined power level. In block 206, a total number of packet signals of Data received correctly is calculated for the first and second portions. The process proceeds to block 208 which determines, based on the total number of data packet signals received correctly, a sensitivity (e.g., a curve or sensitivity, such as curve 104 of Fig. 1) of one or more pluralities (e.g., of a plurality of sensitivity curves, such as the group of normal PER curves 102 of FIG. 1) of expected packet error (PER) regimes against a plurality of levels of power of data packet signals. In block 210, method 200 ends with the determined sensitivity provided for test evaluation and sensitivity screening. In an alternative embodiment, the process of the block 208, instead of determining a sensitivity or sensitivity curve by itself, compares the calculated total number of data packet signals received correctly to a predetermined number. The calculated total number of data packet signals received correctly from the method is closely correlated to the sensitivity. If the calculated total number of data packet signals received correctly is equal to or greater than the predetermined number, the data packet receiver receives the test; also the receiver of data packet signals fails the test. The calculated total number of correctly received data packets is still trackedfrom the tested receiver to the next one to track the direction and rate of change in receiver sensitivity. In block 210, method 200 ends with the receiver passing or failing the test. The determination of a curve or sensitivity in block 208 can be done, for example, in the following manner. In this example, block 208 includes first selection of a data structure of a plurality of pre-constructed data structures (e.g., a plurality of tables). The selection may be based on the first and second power levels (e.g., -72 dBm and -78 dBm) corresponding to the first and second portions and the number of packets transmitted in each of the first and second portions ( e.g., 100 packets transmitted in each portion). The selected pre-constructed data structure can associate a total number of correctly received packets to a curve or sensitivity level. The total number of data packet signals received correctly can then be compared to the selected pre-built data structure (e.g., the total number can be used as a key to perform a table search in a table curve structure) for determine a curve or level of sensitivity. For example, the selected preconstructed data structure may return or determine curve 104 of FIG. 1 for a total number of 192 packets received correctly from 300 transmitted packets. Or if 170 packets were received correctly from the 300 transmitted packets, the selected pre-built data structure can return the curve 105 of Fig. 1. Therefore, the selected pre-built data structure can be used to perform a sensitivity level search. or sensitivity curve for the signal receiver of data packets based on the total number of received packets correctly. In an alternative embodiment, three power levels of data packets are transmitted. A first portion of data packets is transmitted at a power level (e.g., -72 dBm) above the predetermined power level (e.g., -75 dBm), another portion is transmitted at a power level. power (e.g., -78 dBm) below the predetermined power level, and a third portion is transmitted approximately equal to the predetermined power level. A preconstructed data structure (e.g., a table data structure), which may correspond to the three power levels of the transmitted packets and selects the number of packets transmitted in each of the three portions. The total number of data packet signals received correctly is then compared to the selected pre-built data structure (e.g., the total number can be used as a key to perform a table search in a data structure of tables) to determine a curve or level of sensitivity between the curves or levels of sensitivity available in the selected preconstructed data structure. In yet another embodiment, at least two portions of a plurality of data packet signals are received, each portion having packets with different power levels. A total number of packets received correctly is calculated from at least two received portions. One of the one or more plurality of packet error rates (PER) expected against a plurality of data packet signal power levels is determined based on the total number of correctly received packets. For example, a sensitivity curve, such as curve 104 of FIG. 1, is determined from a set of sensitivity curves, such as the group of normal PER curves 102 of FIG. 1. The determination can be made selecting first, based on the power levels of data packet signals associated with at least two portions and the number of packets transmitted in each of at least two portions, one of a plurality of pre-built data structures. The total number of data packet signals received correctly can be compared with the selected preconstructed data structure to determine one of one or more plurality of data regimes. packet error (PER) expected against a plurality of data packet signal power levels. Fig. 3 illustrates a flow chart describing an example of a method 300 for measuring a sensitivity level of a data packet signal receiver according to another embodiment described herein. The data packet signal receiver has a sensitivity characteristic defined by one or more pluralities (e.g., the group of normal PER curves 102 of FIG. 1) of packet error rates (PER) expected against a plurality of data packet signal power levels. The method 300 starts at the start block 302 with the transmission of a plurality of data packet signals to the data packet receiver. The process proceeds to block 304 which includes receiving the plurality of data packet signals as the first and second portions having correspondingly first and second power levels of a plurality of data packet signal power levels. The first power level (eg, -72 dBm), corresponding to the first portion, is greater than a predetermined power level (eg, -75 dBm), and the second power level (v. gr., -78 dBm), corresponding to the second portion, is less than the predetermined power level. In block 306, the first and second PER they are calculated corresponding to 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 and second PER calculated to the corresponding ones of one or more expected PER pluralities (e.g., one or more sensitivity curves, e.g., the group of normal PER curves 102. of Fig. 1) to determine the best fit or equalization curve for calculated PER. For example, a calculated PER of 30% for a portion of transmitted packets with a power level of -76 dBm and a calculated PER of 3% for a portion of transmitted packets with the power level of -74 dBm, using the group of normal PER curves 102 of Fig. 1, determine or better match curve 104 of Fig. 1. In block 310, method 300 ends with the given sensitivity provided for test evaluation and sensitivity tracking. In an alternative embodiment, three power levels of data packets are transmitted. A first portion of data packets are transmitted at a power level (e.g., -72 dBm) above the predetermined power level (eg, -75 dBm), another portion is transmitted at a power level. power (e.g., -78 dBm) below the predetermined power level and a third portion is transmitted approximately at or equal to the predetermined power level. PER are calculated for the first, second and third portions. The three calculated PERs are then compared to find, eg, used to match or better fit a sensitivity curve of a group of sensitivity curves, eg, the sensitivity curve 104 may be a worse fit. or even with the set of normal PER curves 102 of FIG. 1. In yet another embodiment, more than three portions are transmitted, each portion with a different power level of data packets. PER are calculated for each of the received portions. More than three calculated PERs are used to match or better fit a sensitivity curve of a group of sensitivity curves, eg, the sensitivity curve 104 may be a better match of the group of normal PER curves 102 of the Fig. 1. Fig. 4 illustrates a graph 400 showing an example of a transmitted sequence 401 of three consecutive data packet signals, 402, 404 and 406 according to a mode described herein. In this mode, each data packet signal has a different power level. For example, the data packet signal 402 has a power level 408 of about -1 dB (relative to a reference power level), the data packet signal 404 has a power level 410 of about +2 dB , and data packet signal 406 has a power level 412 of about -4 dB. The sequence 401 may be transmitted a predetermined number of times to provide the plurality of transmitted data packet signals to test the data packet receiver. Therefore, an equal number of data packet signals can be transmitted at each power level to provide a first portion of data packet signals in -1 dB, a second portion of data packet signals in +2 dB, and a third portion of data packet signals at -4 dB. The transmission device may require to produce rapid precise changes in the power level or amplitude of consecutive packets, and for short separation times between packets, as shown by the example of Fig. 4. An approach to achieve said changes of Fast and accurate power level in consecutive packets may be the increase of a baseband representation of the data packet signal to produce data packet signals of the augmented baseband. The signals of increased baseband data packets can be converted and transmitted. Each increased baseband data packet is converted to a data packet signal with an associated power level and corresponding to the increase for the data packet. In this way, signals from consecutive data packets with fast and precise changes in amplitude or power level are They can produce and transmit. The use of an external attenuator, in this case, may not be required. For example, the baseband representation of a data packet signal may be a digital representation of the data packet signal in the digital domain. The increased baseband signal data packet may be an enhanced digital data packet signal. A first digitally enhanced data packet signal can be produced from the digital representation by multiplying the digital representation by an increase factor, eg, a magnification factor of 0.5. The digital representation may be multiplied by a different magnification factor, eg, 0.7, to produce a second digitally enhanced data packet signal, and when multiplied by yet another different magnification factor, eg, 0.3, it can produce a third digitally enhanced data packet signal. The first digital data packet signal augmented when converted by a digital-to-analog converter (DAC) can 'produce the data packet signal 402 of FIG. 4. The second and third signals of Increased digital data packets when converted by the DAC can correspondingly produce the data packet signals 404 and 406 of FIG. 4. The data packet signals 402, 404, and 406 can be transmitted as data packet signals of radio frequency (RF) in the RF domain to be received by the receiver of data packet signals. The data packet signals of the increased baseband to produce the plurality of data packet signals for a receiver test can be stored in a memory of the transmission device. The baseband data packet signals can finally be recovered from the memory, when desired, and converted and transmitted. In an alternative embodiment, the increased baseband data packet signals, e.g., the first, second and third data packet signals of the augmented baseband corresponding to the data packet signals 402, 404, and 406, are stored in a memory of the transmission device. When desired, the stored increased baseband data packet signals are repeatedly recovered, converted and transmitted by some predetermined number of times to produce the transmitted stream or plurality of data packet signals to test the receiver that is tested. . As described above for Fig. 4, there can be three portions, each portion with a signal power level of different data packets. In an alternative embodiment, there can be two portions of a plurality of data packet signals, each portion having Different power levels of data packet signals. Sequence 401 of Fig. 4 may include only two packets, each at a different power level, and therefore produce, when repeatedly transmitted, the two portions. In yet another embodiment, there may be more than three portions of a plurality of data packet signals, each portion having different data packet signal power levels. Sequence 401 of Fig. 4 may include more than three packets, each at a different power level and thus produce, when repeatedly transmitted, more than the three portions. Fig. 5 illustrates a block diagram of an example of a test system 500 configured to measure a sensitivity level of a data packet signal receiver (DPS) 502 of a device under test (DÜ) 504. It can be in the case that DUT 504 is the DPS 502 receiver, or as shown in Fig. 5, the DPS 502 receiver may be a digital signal processor (DSP) chip, v.gr ., an RF microcircuit, which is a component separate from the DUT 504. The test system 500 has a transmitting device, eg, a vector signal generator (VSG) 506, for transmitting a plurality of packet signals of data to receive the DPS receiver 502 in the DPS receiver 502 test. A transmission means 508 allows the transmission of the plurality of data packet signals from a transmitter 510 of the VSG 506 to the receiver. DPS 502. The transmission medium 508 may involve a wired or wireless connection. As shown in Fig. 5, VSG 506 includes a memory 514, a digital-to-analog converter (DAC) 512, and the transmitter 510. The memory 514 can be used to store signals from baseband data packets 516. The increased baseband data packet signals 516 are retrieved from the memory 514 and made available to the DAC 512 to produce the plurality of data packet signals as previously discussed for FIG. 4. For example, the Enhanced baseband data packet signals 516 may be increased digital data packet signals that are input to the DAC 512 to produce the plurality of data packet signals as transmission information 518 for transmission by the 510 transmitter. of a subgroup or a complete group of increased baseband data packet signals 516 may be stored in memory 514 to be used in order to generate the plurality of packet signals e data. If only one subgroup is stored, the subset of increased baseband data packet signals 516 are converted once the data packet signals for transmission can be transmitted a predetermined number of times to produce the plurality of transmitted data packet signals. The DPS receiver 502 may or may not require the establishment of a link in order to receive the transmitted plurality of data packet signals. The situation may be that the DPS receiver 502 is a separate component of DUT 504 and the DUT 504 can provide special impellers to the DPPS receiver 502 to keep the receiver 502 in a constant listening mode, expecting to receive the packet testing sequence. . In the situation where a link needs to be established before the receiver 502 is ready to receive, the link can be an asynchronous or synchronous link. Another device (eg, a gold card) not shown in Fig. 5 can generate a sequence to establish a packet link to the DPS receiver 502 to establish the link. Once the link is established, the gold card switches to VSG 506 for VSG 506 to generate the packet testing sequence. In the situation of a link, the DUT 504 recognizes a received packet, but as long as the VSG 506 does not transmit while the DUT 504 is sending the acknowledgment, no problem should occur. This can easily be achieved by inserting a space spacing between the transmitted packets to allow time for a receipt to be received. recognition of a previously transmitted packet. A standard or a specification usually specifies the minimum interval between packets, eg, the 802.11 standard specifies 340 microseconds between the transmitted packets, a 502.11 DUT of 802.11 assumes the present link and operation. VSG 506 simply ignores the acknowledgments returned for transmitted packets. An alternative to using an eternal device, such as a gold card, to establish a link is to "imitate" the DUT 504 in a link. The VSG 506 may send an appropriate link-establishment sequence of packets to the DUT 504 to mimic the DUT 504 assuming a link is established. For example, the VSG 506 may generate a sequence to establish a packet link according to the 802.11 standard to mimic the 502.11 DUT 504 assuming a link is established. After transmitting the packet link establishment sequence, the VSG 506 subsequently generates and transmits the packet test sequence to the DPS 502 receiver. Two methods can be applied to distinguish between the sequence for establishing the packet link and the sequence of test packages. The first method interrupts or defines the VSG 506 when the number of received packets begins to increase, eg, the link is established, in order to read the number of received packets correctly from the 5043 DUT. Stopping the VSG 506 briefly does not create a problem with an asynchronous link since normally the way the connection is established affords the FSG 50 '6 to be the master of the link. Therefore, the transmission may be paused to read the number of received packets correctly from the DUT 504 after the transmission of the packet link establishment sequence. The total number of received packets correctly after the transmission of the packet test sequence can therefore be adjusted to take into account the number of received packets correctly received from the transmission of the sequence to establish the packet link. The other method discounts the number of correctly received packets from the transmission to establish the packet link knowing the number of packets transmitted in the sequence to establish packet links. The transmission of packet link establishment sequence at an increased power level and at a bit rate as low as possible is almost always successful in establishing a link. The known number of packages to establish a link, all having been supposedly received correctly by DUT 504, can be subtracted from the total number of packets received. correctly after transmitting the packet test sequence. The present situation where the required link is established in a synchronous link may require more care to stop transmission by VSG 506. However, persons with ordinary experience in the field can easily identify places in the link protocol in which You can stop and restart the transmission without losing the link. By briefly stopping the transmission, then subsequently re-establishing the connection, there should be a relatively simple task using modern VSG 506 in relation to an internal or external drive signal. An alternative approach to transmit packets at different power levels may be taken to still achieve the results to determine the actual sensitivity level of a data packet signal receiver (e.g., based on the equalization of PER calculated with expected PER ) or a calculated total number of correctly received packets that correlate with the actual sensitivity level, without significantly increasing the test time. The alternative approach transmits a train of test packets at the same power level (so that it does not change the transmitted packets), but they are modulated differently. Instead of transmitting portions of packages with each portion having packets at a power level different from the packets of other portions, each portion differs from the other portions by having the packets of the portion transmitted and received in a different modulation from the packets of other portions. The use of this approach assumes, although it has a system or receiver that supports multiple bitrates, eg, like the IEEE 802.11 system. Please note that the term "bis regime" can be used instead of "modulation" within this application, but what is sought by a change in the bit rate or modulation is a change in sensitivity or SNR. Although decreasing the bit rate may result in obtaining a better sensitivity, there is necessarily no guarantee of better sensitivity of the bit rate decrease. The bit rate can be lowered to transmit more power or occupy less bandwidth. Therefore, the term modulation can be a better term than the bit rate since a change in modulation results in a different sensitivity. Fig. 6 illustrates, for example, a graph 600 showing an example of yet another transmitted sequence 601 of three consecutive packets 610, 620 and 630 according to one 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 each one is transmits and receives a different bit rate. For example, although each of the packets 610, 620, and 63 has the same number of bits, the packet 610 is transmitted in the time slot 640 which is different from the transmission time slot 650 for the packet 620 which is different of the transmission time slot 660 for the pack 630. For example, the time slot 640 can be correlated with 54 Mbps, the time slot 650 at 48 Mbps and the time slot 660 at 36 Mbps. Each of the three packets Consecutive 610, 5620 and 630 are at the same power level, but are transmitted and received in different bit rates. Normally, while maintaining the same power level for the transmitted packets, a sensitivity (e.g., a PER of 10%) can be found corresponding to each of the bit rates for the DPS 502 receiver. For example, the Receiver 502 can have a sensitivity of -75 dBm to receive packets transmitted at 54 Mbps, a sensitivity of -78 dBm to receive packets transmitted at 48 Mbps and a sensitivity of -80 dBm to receive packets transmitted at 36 Mbps. power of the transmitted packets is set to -78 dBm, you would expect to receive almost all or all of the packets transmitted at 36 Mbps, some of the packets transmitted at 48 Mbps, and very few of the packets transmitted at 54 Mbps. Therefore, for example, the FPS 502 receiver with a sensitivity of -78 dBm receiving packets with a power level of -78 dBm can be expected to receive the 100 transmitted packets at 36 Mbps, 90 of 100 packets transmitted at 48 Mbps, and none of the 100 packets transmitted at 54 Mbps. Of the 300 packets transmitted, 190 might be expected to be received correctly if the 502 receiver has a sensitivity of -78 dBm. If the sensitivity of receiver 502 is poorer, eg, -75 dBm, then less than 190 of the 300 transmitted packets could be expected to be received correctly. If the sensitivity of receiver 502 is lower, eg, -80 dBm, greater than 190 of the 300 transmitted packets could be expected to be received correctly. To test a plurality of the DPS receivers 502, the calculated total number of correctly received packets of some predetermined number of transmitted packets (transmitted with portions transmitted in different data bit rates) can be recovered for each of the DPS 502 receivers. The recovered data can be used to indicate the direction of change and / or the rate of change in sensitivity of the tested DPS receivers 502. This final result is very similar to the final result achieved by the process of Fig. 2.

I It should be understood from the foregoing that a single transmission of a group of test packets can be received, test packets transmitted with the same power level but variable bit rates and when received by the DPS 502 receiver. , the total number of data packets received correctly can be compared with a predetermined number. As illustrated by the previous example, the total number of correctly received packets can be closely correlated to the actual sensitivity of the receiver 502. Therefore, the direction of change and the rate of change in sensitivity of tested DPS receivers 502 can tracked by tracking the total number of received packets correctly. Fig. 7 illustrates a flow chart describing an example of a method 700 for measuring a sensitivity level of the DPS receiver 502 according to a modality as described above. In block 702, method 700 begins transmitting a plurality of data packet signals from the DPS receiver 502. Each of the packet data signals has essentially the same power level, but each is transmitted by a rate of bits of one of at least two different bitrates or portions. In block 704, the DPS receiver 502 receives the plurality of transmitted data packet signals. They are received in at least two portions of the plurality of data packet signals, each portion having packets with essentially the same power level. The packets of a received portion are transmitted in the same bit rate that is different from the packet transmission bit rate of another portion. In block 706, the total number of correctly received packets is calculated from the plurality of data packet signals received by the DPS receiver 502. In block 708, the total number of correctly received packets is compared to a predetermined number. The DPS 502 receiver passes a sensitivity test if the total number of correctly received packets is equal to or greater than the predetermined number, or does not pass the sensitivity test in any way. In block 710, the test result (approved / not approved) and the total number of correctly received packets become available to the test or user and the method 700 terminates. In an alternative mode, in block 708 the Total number of correctly received data packet signals is used to determine the sensitivity of the data packet signal receiver The data packet signal receiver may or may not approve a test based on the given sensitivity. In block 710, the sensitivity of the data packet signal receiver and / or the test results are returned to the user or who performs the test. The method 200 of FIG. 2 may be more flexible than the method 700 of FIG. 7 due to the ability or inability of the receiver to receive packets at different bit rates. However, when the test receivers can receive different data bit rates, an implementation advantage of the method 700 can be provided by using a DUT communications device instead of a BSG. A communications device can usually send packets with different data rates easily while maintaining the same power level. For example, a so-called "golden unit" can be used instead of generating the packages. The gold unit usually can not change the output power on a per-packet basis, but usually it can easily change the modulation (eg, data bit rate) on a per-packet basis. Therefore, the approach to changing the bit rate while maintaining the same power output for the transmitted packets is useful when testing with gold units. The golden unit gets its name based on the normal use of a well-characterized device, in this case for a transmission or generation source, and therefore the name "golden unit".

It should be understood that the methods of Fig. 2 and Fig. 7 can also be combined. By doing so, the power of individually transmitted packets could change to achieve a desired separation. For example, in the previous description of Fig. 6, if the portion of the packets were received at -80 dBm instead of -81 dBm, one could do so by subtracting 1 dB of signal power of 36 Mbps. The two methods can also provide the ability to satisfy a need to increase the dynamic test range. For example, assume that 40 dB of SNR is required to ensure that noise in the transmitted signal will not affect the measurement. If the FXG is capable of dynamically varying 60 dB, the power can vary from 40 to 60 dB (a range of 20 cB), but for signals like those of IEEE 802..1 a / g, 10 dB is taken for the average peak of the signal. Therefore, the VSG can only effectively change the power on a 10 dB dynamic scale for a fixed RF gain. The increase of the dynamic scale in addition in the system of test could be very expensive 8v.gr., as much for power as in cost). Combining the two methods of Figs. 2 and 7, the test can also be increased in sensitivity (obtaining an increased dynamic scale) without having to reduce the signal-to-noise ratio (SNR), increasing the bit rate modulation of data instead of decreasing the power. In addition, the combination of methods could be used to test a gain step within an RF microcircuit. For example, if the low noise amplifier (LNA) at the front end of the receiver has two different gains, the sensitivity could be tested at both high gain and low gain. This can be done using the same signal in VSG using a packet train that covers, for example, a 20 dB range. If it is only increased in power, it could have problems with SNR (depending on VSG), but combining the modulation and power, a dynamic range of 20 cG can easily reach in the test with limited power variation. Naturally, the test levels (portion bitrates) will change while the high gain LNA (best sensitivity) will receive most packet levels without losses, and the low gain will only receive a few levels. Still, this is acceptable, while the test limits are adjusted accordingly. If this test is performed using a single packet train, it has the advantage of executing slightly faster in case it takes a long time to adjust the gain of the VSG system, in which case the gain only needs to be adjusted once.

Among the various disadvantages, the embodiments described herein provide for the determination of the actual sensitivity level of a signal receiver of data packets under test or a calculated total number of correctly received packets that correlate to the actual sensitivity level, without increasing significantly the test time. In addition, the actual sensitivity data, whether there is a better fit sensitivity curve or a calculated total number of correctly received packets, for the signal packets of data packets tested can be accumulated and tracked for final analysis. For example, observing a trend or direction in the sensitivity traced v.gr. a worsening or improvement of sensitivity, you can find a cause of the trend, v.gr, the trend can be correlated with a change in the provider of a receiver component. The above detailed description of the invention and the examples described therein have been presented for the purposes of illustration and description only and not by limitation. For example, the operations described can be performed in a suitable manner. The steps of the method can be carried out in an adequate order providing the operations and results described. It is therefore contemplated that the present invention covers any and all modifications, variations or equivalents that are within of the spirit and scope of the basic underlying principles described above and claimed herein.

Claims (22)

1. - A method for measuring a sensitivity level of a data packet signal receiver having a sensitivity characteristic defined by an expected packet error rate (PER) against a signal power level of data packets, comprising: receiving first and second portions of a plurality of data packet signals having correspondingly first and second power levels of data packet signals that are greater than and less than, respectively, a predetermined power level; calculating said first and second received portions of a plurality of data packet signals a total number of data packet signals received correctly, and determining, based on the total number of data packet signals received correctly, said expected PER against said signal power level of data packets.

2. - The method according to claim 1, wherein said determination includes: selecting one of a plurality of preconstructed data structures; Y comparing said total number of data packet signals received correctly to said selected one of a plurality of preconstructed data structures to determine expected PER against said signal power level of data packets.

3. The method according to claim 1, further comprising: receiving a third portion of said plurality of data packet signals having a third level of data packet signal strength that is substantially equal to said predetermined power level.; and calculating said total number of data packet signals received correctly from the first, second and third received portions of said plurality of data packet signals.

4. - The method according to claim 3, wherein said determination includes: selecting one of a plurality of preconstructed data structures, and comparing said total number of received data packets signals correctly to said selected one of a plurality of structures of preconstructed data to determine the expected PER against said signal power level of data packets.

5. - A method for measuring a sensitivity level of a data packet signal receiver having a characteristic sensitivity defined by an expected packet error rate (PER) against a signal power level of data packets, comprising: receiving by at least two portions of a plurality of data packet signals, each of at least two portions having a different packet signal strength level; calculating from said at least two received portions of a plurality of data packet signals a total number of data packet signals received correctly; and determining, based on the total number of data packet signals received correctly, said expected (ER) against said signal power level of data packets.

6. - The method according to claim 5, wherein said determination includes: selecting one of a plurality of preconstructed data structures; and comparing said total number of data packet signals received correctly to said selected one of a plurality of preconstructed data structures for determine expected PER against said signal power level of data packets.

7. - A method for measuring a sensitivity level of a data packet signal receiver having a sensitivity characteristic defined by an expected packet error rate (PER) against a signal power level of data packets, comprising : receiving first and second portions of a plurality of data packet signals having correspondingly first and second signal power levels of data packets that are greater than and less than, respectively, a predetermined power level; calculating first and second PER that corresponds to said first and second portions of said plurality of received data packet signals, respectively, and comparing said first and second PER corresponding to said first and second portions of said plurality of received data packet signals , respectively; and compare the first and second PER calculated to said expected PER.

8. - The method according to claim 7, further comprising: receiving a third portion of said plurality of data packet signals having a third level of signal power of data packets that is substantially equal to said predetermined power level; calculating a third PER corresponding to said third portion of said plurality of received data packet signals, and comparing said third calculated PER to said expected PER.

9. - The method according to claim 7, further comprising transmitting said first and second portions of a plurality of data packet signals.

10. - The method according to claim 9, wherein a baseband representation of a data packet signal is increased to produce signals of increased baseband data packets, and data packet signals of Increased baseband are converted and transmitted as the first and second portions of a plurality of data packet signals.

11. - The method according to claim 10, wherein said baseband representation of a data packet signal is a digital representation and the signals of increased baseband data packets are digital data packet signals increased, the signals of augmented digital data packets converted by a digital to analog converter (CAC).

12. - The method according to claim 10, wherein the signals of increased baseband data packets are stored in a memory for subsequent recovery of said conversion and transmission.

13. The method according to claim 12, wherein the stored increased baseband data packet signals are repeatedly converted and transmitted by a predetermined number of times to produce the first and second transmitted portions of a plurality of signals. of data packages.

14. - The method according to claim 7, wherein said reception includes receiving first and second signals from consecutive data packets with the first data packet signal having said first signal power level of data packets and the second data packet signal having said second power level of data packet signals.

15. - A method for measuring a sensitivity level of a data packet signal receiver having a sensitivity characteristic defined by an expected packet error rate (PER) against a power level of data packet signals, comprising : receive at least two portions of a plurality of data packet signals, each of said at least two portions having a signal power level of different data packets; calculating a PER for each of at least two portions of a plurality of data packet signals; and comparing the PER calculated for at least two portions of said expected PER.

16. - The method according to claim 15, wherein at least one of said at least two portions has data packet signals with a power level less than a predetermined power level and at least one power level. at least two portions have data packet signals with a power level greater than the predetermined power level.

17. - A method for measuring a sensitivity level of a data packet signal receiver having a sensitivity characteristic defined by an expected packet error rate (PER) against a signal power level of data packets at a associated modulation, comprising: receiving first and second portions of a plurality of data packet signals having signal power levels of substantially equal data packets and first and second corresponding modulations they are greater than and less than, respectively, a predetermined modulation; calculating from said first and second portions received in a plurality of data packet signals a total number of data packet signals received correctly; and determining, based on the total number of data packet signals received correctly, said expected PER.

18. - The method according to claim 17, further comprising: receiving a third portion of said plurality of data packet signals having data packet signals with a power level substantially equal to the packet signal power level of data in the first and second portions, the third portion having a third module substantially equal to said predetermined modulation; and calculating said total number of data packet signals received correctly from the first a, second and third portions of the plurality of data packet signals.

19. - A method for measuring a sensitivity level of a data packet signal receiver having a sensitivity characteristic defined by a rate of packet error (PER) expected against a signal power level of data packets to an associated modulation, comprising: receiving at least two portions of a plurality of data packet signals, said at least two portions having signals of data packets with substantially equal power levels and each of at least said two portions having different modulations; computing from said at least two received portions a total number of data packet signals received correctly; and determining, based on the total number of data packet signals received correctly, said expected PER.

20. - The method according to claim 19, wherein at least one of at least two portions has a modulation below a predetermined modulation and at least one of said at least two portions has a modulation above the default modulation.

21. - A method for measuring a sensitivity level of a data packet signal receiver having a sensitivity characteristic defined by an expected packet error rate (PER) against a power level signaling of data packets to an associated modulation, comprising: receiving at least two portions of a plurality of data packet signals, the data packet signals of a portion of at least two portions having substantially the same level of power and modulation, and the power and modulation level differing between the portions of at least two portions; computing from said at least two received portions a total number of data packet signals received correctly; and determining, based on the total number of data packet signals received correctly, said expected PER.

22. The method according to claim 21, wherein at least one of at least two portions has a modulation below a predetermined modulation and a power level below a predetermined power level, and at least one of at least two portions has a modulation above the predetermined modulation and a power level above the predetermined power level. s