TW577197B - Self-correlation detection and in-band and out-of-band signal detection for automatic gain calibration systems - Google Patents

Abstract

An embodiment of the present invention provides an automatic gain control system for a wireless receiver that quickly differentiates desired in-band signals from high power out-of-band signals that overlap into the target band. The system measures power before and after passing a received signal through a pair of finite impulse response filters that largely restrict the signal's power to that which is in-band. By comparing the in-band energy of the received signal after filtering to the total signal energy prior to filtering, it is possible to determine whether a new in-band signal has arrived. The presence of this new in-band signal is then verified by a multi-threshold comparison of the normalized self-correlation to verify the presence of a new, desired in-band signal.

Description

577197

BACKGROUND OF THE INVENTION Definition of the Invention The present invention is directed to some communication systems. Specifically, the present invention is directed to receivers in some wireless communication systems. More specifically, the present invention is directed to an automatic gain control system for receivers in such wireless communication systems. '' Description of Related Techniques The use of some receivers in radio systems such as radio and mobile telephone communication systems is well known in the art. Figure 1 shows a typical superheterodyne receiver design. Here, a radio frequency (RF) signal is received on the antenna 15 and will be provided to an RF amplifier 20. This RF signal will be amplified by its RF amplifier 20, and will be mixed in a mixer 25 'with a signal from a local shaker 30. This will produce an intermediate frequency (IF) signal that will be amplified in an iF amplifier 35 and filtered in a band-pass filter 40. The filtered if signal will be amplified again in an IF amplifier 35, and will be amplified in an band pass filter 40, by an IF amplifier 45, and in a product detector 50, and one from one. The signals of the beat frequency oscillator 55 are mixed. The result is a signal amplified by a band-pass amplifier 60 and digitized by an analog-to-digital (A / D) converter 65 for further processing. In these receivers, a stronger signal requires a smaller amplifier gain, and an extremely strong signal, which is not amplified so that when it is amplified, it will distort the received information signal, overload system components, and possibly It is important that these components are damaged. For this reason, they received 4 (please read the notes on the back before filling out this page)-order — this paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) 577197 A7 B7 V. Description of the invention ( 2) " " — (Please read the notes on the back before filling this page) The machine typically has some kind of automatic gain control (AGC) system, which can control or more system amplifiers 20, 35, 45, and 60, so that these amplified signals are maintained within a certain range (for example, this control may be a bias voltage applied to the amplifiers via a target). In Fig. I, its AGC unit 70 can receive the iF input output from its IF amplifier 45, and can use it to generate some bias signals that can control these size amplifiers 20 and IF amplifiers 35 and 45. SUMMARY OF THE INVENTION One embodiment of the present invention provides an automatic gain control system related to a wireless receiver, which can quickly distinguish signals in a desired frequency band from some high-power out-of-band signals that overlap into its target frequency band. This system can measure the power of a received signal before and after passing through a number of filters that substantially limit the power of the signal to those in its frequency band. By comparing the energy in the filtered frequency band of the received signal with the total energy before filtering, it will be possible to determine whether a new signal in the frequency band has arrived. The appearance of the signal in this new frequency band will then be confirmed with its multiple thresholds of normalized self-correlation to confirm the existence of a new signal in the desired frequency band. These and other features of one embodiment of the present invention are briefly illustrated in the drawings, and will be more clearly understood by reading the following detailed description of the preferred embodiment with the accompanying drawings, wherein: The figure shows the structure of a communication receiver according to the prior art. The second figure shows the structure of a communication receiver according to an embodiment of the present invention. The paper size is in accordance with China National Standard (CNS) A4 (210X297). (Public love), description of the invention (editing the graph system, showing the structure of the automatic gain control mechanism according to the embodiment of the present invention; f 4 and 5 graphs showing the desired characteristics of the signal of increasing pureness; the graph system shows this The characteristics of the saturation of the A / D adapter in the embodiment; and Figures 7A, 7B, 8 A, and 8B show the characteristics of their in-band and out-of-band signals. The basic structure of the receiver is shown in the first one of its I-band antenna 115, which can receive a radio frequency (RF) RF L #u and can be provided to-RF amplifier 12o, and special features in this band Channel or signal, preferably by The local oscillators 130 and 180 are changed to make a choice. In this embodiment, the ruler signal preferably conforms to the IEEE 802.1 1 la standard, has a frequency in the 5 GHz band, and is orthogonal. Modulation to transmit 6 to 54 Mbps. In this embodiment, the 仏 number can transmit data up to 54 Mbps, and is located in one of twelve 20 MHz, eight of which are at 5.15- 5.3 In the 5 GHz band, and four in the 5.75-5.85 GHz band. The signal in this embodiment is an orthogonal frequency division multiplexed signal (OFDM using 52 subcarriers spaced 312.5 kHz apart). However, it should be understood that although the following detailed description is completed in the context of an IEEE 802.1 1 1a standard, the invention described in this specification is applicable to many different types of communication systems' and is not subject to It is limited to some systems operating in this IEEE 802.1 1 a standard. For example, as described below, the present invention is described as a short and long coaching symbol (trainin 6 ( Please read the notes on the back first (Write this page) This paper size applies the Chinese National Standard (CNS) A4 specification (210 X 297 mm) 577197 A7 ------- PZ______ 5. Description of the invention (4) symbol) 'But it should be noted that its Relevant teaching can be generalized to any coaching sequence composed of one or more sine waves. Therefore, for example, the measurement of their power can be based on a training symbol that exists in a coaching symbol that contains most sine waves The slowest frequency sine wave is completed in half a cycle, and each majority sine wave has a frequency that is an integral multiple of its slowest frequency. In 802.1la systems, this translates into half of a short coaching symbol sequence. The amplified RF signal is mixed with a signal supplied from a & RF oscillator 13 to a mixer 125 to generate an intermediate frequency (IF) signal, which is then fed to an IF amplifier 135. The frequency and value of the local RF oscillator 13 and the local IF oscillator 180 are preferably in the range of 515-5 35 and 5.75_5 85 (5 edges, so that the RF oscillator frequency is equal to the IF oscillator frequency. The ratio is 4: 1. In this embodiment, the local oscillators 13 and 18 are preferably in a floating IF configuration, where they are all variable instead of A fixed IF configuration where, for example, only the local RF oscillator 13 is variable. The amplified IF signals are supplied to a common-phase mixer 175-IP and a quadrature mixer, respectively. 175_Q, one of the equivalent phase mixer 175_ιρ and a quadrature mixer 175-Q, is directly driven by a local clock oscillator 180, and the in-phase mixer 175-Ip and a quadrature mixer The other of i75_q t is 90% in a phase shifter 185. After the phase shift, it is driven by the local IF oscillator. In this way, the received signal is in phase (IP) and positive The cross (Q) component will be obtained at the outputs of the equivalent phase mixer 175-IP and the quadrature mixer 175_q. Associate (cns) A4 size (21〇 \ 297 billion public ^ " ---------

:… Bu- 磬…: (Please read the notes on the back before filling this page)-Order, V. Description of the invention (5) These mixed IF signals will pass through some low-pass filters 14〇_Ip And 140-Q, so as to select their desired channels, and remove their unrelated components that are separated on the frequency side, and will be amplified by two serially connected baseband amplifiers 145-IP and 145-Q. Although two baseband amplifiers are shown in each branch, a different number of amplifiers can be used. In a particular sequence, using some baseband amplification with a properly selected programmable gain, a configuration that can develop any desired baseband gain step. The low-pass filters 14 (MP and 140_Q are preferably some two-pole elliptical filters with a 3 dB cross angle at 28 MHz. Moving from analog to the digital domain, the output of these baseband amplifiers is fed to Their A / D converters 190-IP and 190-q, they can digitize the signals of the equivalent phase and quadrature components, preferably at a frequency of 80 MHz to a resolution of nineteen bits: And an input dynamic range of -500 mV to 500 mV. These A / D converters are preferably some pipeline A / D converters; however, the present invention is not limited to this. For example, Δ or other Converter, can be used to replace them. Analog channel filter. The skin is, spear and / or anti-aliasing crossing; the leather device can be advantageously placed before these A / D converters 190-IP * 190_Q. In the preferred embodiment, a combination of analog and analogue wave filters can perform adjacent block signal rejection of 4 offenses and 20 dB of alternate block signal rejection. On the larger side of 16 offenders, block k and 32 Worst case of alternating blocking signals with larger dB '-the receiving blocking signal at the input of its A / D converter can be U dB higher than the signal in its frequency band. As is well known in the art, “adjacent blocking signals” are interfering signals adjacent to or overlapping with the frequency band of interest, and 577197 A7 ------- 丨 丨 B7 _ V. Description of the invention (Ό) An alternate blocking signal is an interference signal far from the frequency band of interest. The digitized I / Q component signals are supplied to an automatic gain control (AGC) unit 170 ' The operation of the invention will be described in more detail below. This AGC 170 can be described in more detail below, analyzing the ι / Q component h number, and can generate some gain control signals based on it. These gain control signals As shown by the dashed lines in Figure 2, these are supplied to these amplifiers 120, 135, 145-IP, and 145-Q. More specifically, as shown in Figure 3, these are from A / D The digital signals of the converters 190-IP and 190-Q pass through some leaky barrel filters 245-IP and 245-Q and FIR filters 205_Ip, 21CMP, and 205-Q , And 210-Q. The first FIR205_Ip and 205-Q are some decimation filters, which can be obtained from their corresponding data. Stream, eliminating every other sample, thereby reducing the data sampling rate from a normal 8.5 MHz single-sideband bandwidth packet 'from 80 MHz to 40 MHz. 2o-(^) are standard low-pass filters that can remove any remaining adjacent or alternating blocking signals before transmitting data to their autocorrelator 225 and a power detector 220. Within its Agc 170, secondary power measurements will be made, once from the output of its second FIR filter 21, by its power detector 220, and once from its A / D converters 190-IP and 190. The output of -Q is completed by another power detector 215. These measurements are supplied to its AGC control logic 230 as explained in more detail below. Although this embodiment uses digital FIR, other types including filters such as analog filters and wave filters can be used instead. If the system is not to be oversampled, the filters are preferably of analog type. This paper scales the family standard (⑽) M specification ⑵⑽ tears and love) 9 (Please read the precautions on the back before filling this page) Order — 577197 A7 _____B7_ V. Description of the invention (7) Its AGC control logic circuit 230 Can receive some power measurements from the power detectors 215 and 220 and use them to control a gain control generator 235 to generate each RF amplifier 120, IF amplifier 135, and individual baseband amplifiers 145-IP and 145 -Q related analog gain control signal. In this embodiment, the AGC control logic circuit 230 can provide a control block, which is ten bits long in this preferred embodiment. The gain control generator 235 and the gain control generator 235 can provide Generate appropriate control signals for these amplifiers. These gain control signals will be fed back to the RF amplifier 120, IF amplifier 135, and baseband amplifiers 145-IP and 145-Q, so as to control the gain of each as described above. This embodiment uses a dedicated integrated circuit to embody the AGC control logic circuit 230; however, a properly programmed processor, internal or discrete 'or other suitable device, can also be used. It should be noted that although Figure 3 shows the individual components within the AGC 170, two or more units may be integrated into one unit to separate them from each other. For example, a 'the AGC control logic circuit 230 is shown to be separated from the firs 205, 210, power detectors 215, 220, and the auto-correlation unit 225; however, these several can be combined into a single processor And do proper programming to perform these functions. In addition, a programmed processor does not need to be used, and one or more of these components can be implemented in dedicated hardware. The AGCn0 can control a DC offset control unit 24, thereby providing some analog offset control signals to one or more of the baseband amplifiers ΐ45_ιρ and 145-Q. The DC offset control is completed, which can ensure that these paper sizes are applicable to the Chinese National Standard (CNS) Α4 specification (210X297 mm) (please read the precautions on the back before filling this page). May | 10 577197 A7 B7 V. Explanation of the invention (8 rams and 8 / D conversions to analog signals of 19-IP * 19〇_q are appropriately concentrated and quantified. (Please read the notes on the back before filling this page) AGC Operation — In this embodiment, the control logic circuit 230 first checks to see if the edge number will sufficiently saturate any A / D converter 19〇-IP * 19〇_q. Right, a The rapidly decreasing gain control program will be executed; if not, it will be explained below, a basic gain control program will be executed. Secondly, its basic gain control logic circuit 23 will decide to receive it. Is the signal within a better range as described below. If so, gain control is not required; otherwise, the gain control procedure described in more detail below is performed. Next, the AGC system 170 will attempt to use Some will do as follows Detailed description of strong and weak signal detection technology to identify a signal in a frequency band. If a signal is found, the detection process will be completed; if not, the detection process will be part of the next part of the signal Repeat. Their weak signal detection and strong signal detection are independent and complementary features. As further explained in this specification, as far as strong signal detection is concerned, once The arrival of a strong signal will determine the existence of a signal b, and in terms of weak signal detection, it will determine the possible existence of a signal because the power in the measured frequency band is at least proportional to its Agc Power (when a gain change is not required), it is an auto-correlation that exceeds a critical value. It should be noted that if a gain change is made, it is best to disable the weak sign detection. Microseconds, because the paper size of this paper is up to the Chinese national standard (Which) A4 specification (21〇 > < 297 mm) 11 A7 ^ " ~ ____ B7 V. Invention description (9) ----, Relevant windows fill them Before the gain changes, the auto-correlation will not be released. Therefore, the weak signal detection is used for some arriving signals that are not large enough compared to the blocking signal or noise, and the strong signal debt measurement is for some Larger arrival signals. As far as strong signal detection is concerned, a new 4 "Tiger has arrived, as explained below, the decision is based on whether a coarse increase or rapid decrease gain is generated. Basic gain control In operation, its AGC 170 must adjust the gain of their receivers so that the ^ number they receive can be properly quantified by their A / D converter i 90. If this number is in their A / D converter The input is too large and this signal will be distorted by saturation. If this signal is too small at the input of its A / D converter, the quantization noise of its a / D converter 190 will cause the signal-to-noise (S / N) ratio it receives to be too small for board preparation. low. For this purpose, the Agc control logic circuit 230 'uses the gain control unit 235 as described above to digitally control the analog variable gain stages. Preferably, the gain control of this embodiment has a dynamic range of 93 dB to 51 dB in the combined RF and IF stages 120 and 135, and 42 dB in its baseband stage 145.

Its power detector 215 can estimate the value by adding a window of instantaneous power calculation for a total of 16 samples and a half-preamble short symbol window within an 802.1 1a signal (400 ns). Wait for the total power of the A / D converters 190-IP and 190-Q. For example, consider a signal from the 9-bit a / d converter 190 in the range [_256,255], which is related to the 16-bit sample window of this signal in the semi-preamble short symbol window. The measured value of the power. To accomplish this, its AGC control logic circuit 230 will calculate its A / D. This paper size is applicable to the Chinese National Standard (CNS) A4 specification (210X297 mm). 12 (Please read the precautions on the back before filling this page)

577197 A7 _B7_ _ V. Description of the invention (10) The instantaneous power adcpwrl on the converter output stream adcoutput is 15 adcpwrl = ^ (real (adcoutput [k])) 2 Λ- (imag (adcoutput [k])) 2 (1 ) k = 0 This power measurement is then placed in a logarithmic table, where the maximum value is zero. Thus, for every fully railed output at -256 for each value, its logarithmic table output will be zero. The power of a complete rail sine wave will be -3 dB; if each sample is 128, its power will be -6 dB, and so on. Its AGC control logic 230 uses this total power estimate to maintain its signal within the range of these A / D converters 190-IP and 190-Q. If its signal power is determined to be out of range (but does not saturate these A / D converters 190-IP and 190-Q), a coarse gain change will be made to bring the signal back into its range . More specifically, if its AGC control logic 230 detects that the total measured power adcpwrl (in this embodiment, in the range of -63 -OdB), it is greater than its maximum desired A / D converter signal scale , Its desired gain value gaintarget, this signal scale is set to be large enough to make its quantization noise small enough, but also small enough to saturate the ADC is not a problem, but includes the signal and any potential blocking The scale of the signal is reduced by its AGC control logic circuit 230 during a coarse gain drop, and is reduced by the following equation: gaintarget = gaintarget + (coarsepwr_const-adcpwrl) (Figure 4), for example, -17dB. This amount of gain loss is used because the incoming signal may be too large for quantization, but as explained in more detail below, it is not large enough to trigger a rapid decline. For example, if the signal is even 13 (please first Read the notes on the reverse side and fill in this page) This paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) 577197 A7 B7 V. Description of the invention (11) It is saturated, but not enough to trigger a rapid decline. In these cases, it would be useful to reduce its gain more than the value indicated by its gaintarget based on a saturated waveform power measurement—a very strong value. Therefore, the coarsepwr_const value determined by the above experiment is added to increase the gain and decrease so that it can converge to its desired signal scale more quickly. This result is used to generate appropriate control signals for these amplifiers via its gain control generator 235. If its total measurement power adcpwrl is smaller than its minimum desired A / D converter signal scale, the desired gain value gaintarget will be increased by its AGC control logic circuit 230, with the following equation: gaintarget = gaintarget + (totalsizede sired -adcpwrl) (3) where totalsizedesired is the target A / D converter signal scale during their coarse gain change, that is, their A / D converter output is in the absence of a desired signal (Figure 5) The desired scale is about -17 dB in this preferred embodiment. If the AGC's rapidly-decreasing gain control signal often saturates these A / D converters 190-IP and 190-Q, an accurate power measurement may not be available; however, the signal is partially in the range outer. This information can be used to quickly reduce its gain. More specifically, a saturation counter adcsat is established by its AGC control logic circuit 230 to count the number of saturations of the I or Q A / D converter output samples. A pair of saturation thresholds, adcsat_thrh and adcsat_thrl, which can be changed by downloading a different threshold, are used to count the possible lack of any A / D converter output range. Therefore, a saturation will be applied to Chinese paper standard (CNS) A4 specification (210X297 mm) for this paper size 14 (Please read the notes on the back before filling this page)-、 可 | 577197 A7 B7 V. Description of the invention ( Π) It is detected that if adcoutput ^ (adcsat_thrh + 192) (4) or if adcoutput ^ (adcsat_thrh + 192) (5) where adcsat_thrh is a high critical value that is less than its maximum A / D converter output value, It indicates saturation on the high side of the A / D converter output. Adcsat-thrl is a low critical value that is greater than its minimum A / D converter output value. It indicates the low side of the A / D converter output. The saturation above (Figure 6) and the fixed values are now dependent. adcsat_thrh is set to be slightly lower than its maximum A / D converter output, while adcsat_thrl is set to be slightly higher than its minimum A / D converter output. This is useful because it allows some signals that are close to the saturation of the A / D converter but not actually saturated to be classified as saturated signals for more flexibility. During a sample window of an adcsat_icount cycle (preferably less than or equal to eight, a quarter-the number of cycles in the measurement window of symbol 802.1 1a), if the A / D converter outputs a saturated number of samples, Above a saturation threshold value adcsat_thresh, its AGC control logic 230 will indicate a rapid gain drop and gaintarget will decrease by a predetermined amount of quick_drop, for example, a gain change of -30dB. In this preferred embodiment, the adcsat_thresh is set for a threshold value of 12 saturations in an 8-period window (so that their saturation may be independently based on their I and Q ADCs). This technique may be advantageous Land is realized in the following way. After calibration or any gain change, an AGC settling time will occur. In adcpwrl, this paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) 15 (Please read the precautions on the back before filling this page), OK | Table — 577197 A7 B7 V. After the description of the invention (l3), Its variable corresponding to the amount of measured power will be reset, and an acc_count counter, preferably an 8-bit increment counter that continuously cycles during AGC operation, will also be reset. The counter acc_count will have the following events: mod (acc_count, 16) = 0: reset the adcpwrl accumulator mod (acc_count, 16) = l: clear the reset above the adcpwrl accumulator mod (acc_count, 16) = 2: Store adcpwrl mod (acc_count, 16) ^ adcsat icount and adcsat = l (declared when set_thresh is saturated, for example, eight saturations have been counted), its saturation counter has exceeded adcsat_thresh, and a rapid gain drop should be carried out. As shown, in this preferred embodiment, the adcpwrl values are calculated every 16 cycles, and before the system records a value greater than adcsat_icount (preferably 8), adcsat will be expected Be declared. AGC packet detection Once the signal from its receiver is within range, its AGC control logic 230 will detect the presence of a desired packet. Based on this, its AGC control logic circuit 230 can determine the power estimation value in a frequency band. The FIR filters 205-IP, 210-IP, and 205-Q, 210-Q can be used to reduce all adjacent sums. Alternate blocking signals make the signal power in the frequency band below the maximum level specified by 802.1la 20 dB lower, and adcpwrl and Hrpwrl can be compared as described below. This is done to get information about the quantized signal energy at its A / D converter 190-IP or 190-Q in or out of the band-a help to find these desired packets News. 16 (Please read the precautions on the back before filling this page) This paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) 577197 A7 B7 V. Description of the invention (14. More specifically, consider Figure 7A The signal shown in the figure, as mentioned above, will be determined by the power output of the A / D converter. The summer measurement of the rms scale of the signal of the full rail signal scale described in the private formula (1). However, as shown in Figure 7B, the signal will lose its second FIR 210 IP or 210-Q '胄Most of the power, & will be reduced to a level of 25 dBr "a reduction of about 85%. Because most of the power of this signal is blocked by its FIR21〇-Ip * 21〇-Q It is assumed to be an out-of-band signal. Referring to the signal shown in Figure 8A, this signal also has a full power of approximately -12 dBr as measured at the output of its A / D converter. However, as shown in As shown in Figure 8B, with its second FIR 21 (Mp or 21〇_q, only reducing it to about -15 dBr- The reduction is only about 10%. Because most of the power of this signal is passed by its FIR21o-Ip or 21〇_Q, it is assumed to be a signal in a frequency band. From this understanding, the power in the frequency band , Calculated as the sum of their instantaneous power measurements, preferably in a 32 sample, similar to the full power calculation of the 0.8 // S window of adcpwrl described above. Firpwrl is based on some less than the total sample obtained The lowest number of samples, such as 28 out of 32 samples within the 32 sample window it detected as 220. It should be noted that the number of samples related to firpwrl is greater than the number of samples related to adcpwri Because firpwd is used for fine gain control, the precision of which is important, and adcpwrl is used for coarse gain control, where the power estimate with a little noise is feasible. It should also be noted that although this is smaller than the total sample The paper size applies to China National Standard (CNS) A4 (210X297 public love)

(Please read the notes on the back before filling in this page)-、 _ MV / V. Description of the invention (15 ^ frequency V power calculation purpose is better used, other analogies after the use of these samples occurred Digital converter processing will usually use the obtained samples. Pages smaller than the total number of samples are used because of the number of interference periods, for example. 纟 ㈣ Interference at the symbol boundary changes due to its symbol migration.乂 Caused by the high-frequency component / knife of interference at the power component in the band within the desired frequency band, a power spike in a temporary band may occur. This will appear unnaturally in its power rate A stepped window at the transmitter of the interference, for example, at its symbol boundary, using a value that is half of its previous value and added to its subsequent value will be like low-pass filtering This makes the ground slightly lower, so that the rest can pass its necessary spectrum mask. Although these instantaneous high-frequency peaks are reduced, they will still exist. When an adjacent interference occurs, this is temporary in the interference signal. High frequency components, real It is in the frequency band related to its desired signal, so that when no desired signal appears, the power measurement value in this frequency band can get a sharp spike of related data samples, such as the increase of power in its frequency band. To prevent it, it uses a minimum of 28 out of 32 samples so that this temporary spike is reset to zero by not counting their values, and their critical values are adjusted accordingly to compensate for missing four. The power measurement value caused by each sample is reduced. However, a signal of interest appears in the first place. In establishing its power measurement value, it is best to use all the samples to make a detailed measurement. This second power measurement value is called Make firrpr all. Using the power information described above, their desired signals can be found in two ways: strong signal detection and weak signal detection. Strong signal detection will be explained first. Paper size applies Chinese National Standard (CNS) A4 specification (210X297 mm) 18 577197 A7 B7 V. Description of the invention (l6) Once a strong signal is detected, the coarse gain decreases or rapid gain as explained above When a drop occurs, its AGC control logic circuit 230 will set a strongsignal flag. This flag will remain at a high logic level until the signal is detected by its A / D converter 190-IP or 190-Q. Decided to be within the range, and its algorithm will continue, so as to complete a firpwrl measurement as described above. In this regard, flag_relpwr is calculated as follows flag_relpwr = set if (firpwrl > relpwr + adcpwr) (6) (Among them, relpwr is an experimental threshold value of the absolute digital scale of the signal in its frequency band relative to the absolute total digital signal at its A / D converter 190-IP or 190-Q), so try to pay attention to most of the calculations. Power is in the frequency band. If flag_relpwr is a high logic level and strongsignal is a high logic level, then a new, extremely strong signal has appeared. In this manner, this embodiment may allow an oversampled incoming signal to be checked, which may have a digitized frequency outside a desired frequency range due to oversampling, and may be determined before a desired signal has been discovered. , First determine whether most of its power is in the frequency band. Therefore, when flag_relpwr is at a high logic level and strongsignal is at a high logic level, its signal_found flag will be announced, a small gain change will be completed as described below, and once the number of their consecutive gain changes, Is equal to or greater than the minimum number of gain changes that it considers to constitute a successful AGC operation, and its AGC procedure is completed, that is, when there are sufficient gain changes in it, and when its system is turned on, a Programmable amplifier rises linearly. 19 (Please read the precautions on the back before filling out this page) This paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm). 5 Description of the invention (Π) In the weak h detection, it is defined as follows The normalization of the short sequence of the short sequence is to find in the preferred embodiment any of the frequency bands with a period of 0.8 #S. This is a two-step procedure performed simultaneously with the strong signal detection procedure described above. First, the system waits for the normalized autocorrelation measured by its autocorrelation processor 225 to exceed a first normalized autocorrelation amplitude threshold m 1 thres. Its association processor 225, preferably on the self-associated data packet measuring 802.1la, obtains 32 samples in a short coaching code symbol by the beginning of a data packet, and compares each sample with a sample from Corresponding samples of his short trainer. More specifically, the self-correlation of an A / D converter stream adc〇utput is expressed as self corr = ΕΣα ^ οι // Ρ ^ [^] · conj {adcoutput [n-32])] 2 ^ adcoutput [ nf (?) where the denominator is a normalization factor. Its molecules can be seen to be quite high when χ [ηρσ χ [η_32] is the same, and, for example, to be relatively low when they are not related. Therefore, this measurement can be used as a good indicator of autocorrelation. Detecting when its auto-correlation output exceeds m 1 thres can thus detect the presence of an incoming packet; however, it will also detect their interference because they may have some structure that can also auto-correlate. For this reason, this embodiment advantageously uses another test. Once its normalized auto-correlation exceeds mlthres, the system enters a loop, and the “max period” is added. In a variable mltally, a count of its normalized auto-correlation exceeds a second constant. This paper scale applies China National Standard (CNS) A4 specification (210X297 public love) 577197 5. Description of the invention (is) The number of times the threshold value m2thres of the auto-correlation amplitude is normalized, where m2thres * is less than or equal to mlthres. If mltally > m2count_thr, the threshold value of normalized self-correlation count > 1112 generation 3, before the period of 1111 (: 01 ^ —11 ^ \ (— the length of the window of its auto-correlation count)) period elapse Weak signal detection can be detected. As noted above, this windowing technique based on mlcount-max is used because both their interference and noise can have a transient over one Threshold autocorrelation, but when sample windows obtained across consecutive periods are used, the chances of this happening will decrease. For example, a subsequent window will contain many of the same as its previous window Samples, but this previous window will not include most recent samples from its successor, and its subsequent windows will not include its earliest samples from its previous window. So, for example, if Two 802Ua symbols are transmitted in adjacent channels, so that they are separated by 20MHz in frequency. The last 0 · 8 // s of the first symbol will be completely different from the next symbol. Once a 108 # $ protection period matches, and is established into self-association However, compared with a preamble, this sharp wave will fade away quickly, and in terms of a preamble period, it is expected that a straight normalized auto-correlation result is obtained. Therefore, this embodiment provides a method for The implementation of self-correlation measurement-a method of two threshold value amplitude t program. Its _ threshold value is used to determine that Lbl may appear in the frequency band. Within the different windows of their offset samples, a second threshold value is The number of times will be counted, so as to further determine whether the signal in the frequency band is a desired signal. This action is to prevent the temporary association of thermal noise Λ, plus the information to prevent an interference signal. Maki

…: — If, (please read the precautions on the back before filling out this page) Order 丨 A7 '_______B7 V. Description of the invention (19 1 ~ --- self-correlation during the period. In addition,' for further strengthening against noise and interference Signal capability, this embodiment preferably requires enable-weak signal detection results, a potential test packet, must increase its signal power in the band to at least a certain amount, and its increase is at least proportional to Any increase in its total signal power means that its power is at least a certain minimum scale. This can provide additional sensitivity when the signal in a new frequency band is lower than an interference signal or close to the noise base value, so it does not Will trigger a strong signal debt test, but there is value in finding a weak signal debt test. Once mltally> mlthresh, at least three things may prevent weak signal detection from happening. First, if ycOK = 0, weak signal detection will not happen YcOK is a decreasing counter. If it is determined that there is an increase in the signal in a certain scale (flag-firstep), and at least proportional to any increase in its total power (flag-relstep), the measured The trip 卬 ~ ^ has a certain minimum scale (flag_flrpwr), it will be reset to ycoKmax (four in this embodiment), so that weak signal detection is enabled, and the new one The signal in the frequency band may be lower than an interference signal or close to the noise base value, so it will not trigger strong signal detection, but it has the value of finding weak signal detection. In order to ensure that such identification occurs within a limited period of time When ycOK > 0 occurs after all, the above will certainly happen. To implement the different steps of this step, the old value of firpwrl * acjCpWr is stored as firpwr (2-4) and adcpwr (2-4 ). Their sufficient values will be stored so that if the signal is detected during a ramp of the programmable amplifier, sufficient differences will exist between its first and last measured values, exceeding its defined threshold. 22 (Please read the precautions on the back before filling this page) This paper size is applicable to Chinese National Standard (CNS) A4 (210X297 public love) 577197 A7 B7 V. Description of the invention (20 Another reason why weak signal detection is possible The reason it doesn't happen is because gc_coun t is greater than zero. gc_count is measured from the last gain change in short symbol increments. After a gain change, each valid firpwrl measurement value from its starting value of 3 is due to its AGC control. The logic circuit 230 reduces the time. The concept is that after a gain change, there is a minimum amount of time until an auto-correlation is valid. Finally, if the signal has been detected by other methods, weak signal detection It will not happen, because then it will not need to use weak signal detection to find it. AGC packet detection-DC 抿 fill clean 昤 The above dual threshold configuration is successful in reducing falsehoods for interference signals during weak signal detection Packet detection; however, it is not particularly successful in preventing false detections with respect to DC signals that they can always auto-correlate. At the output of its A / D converter 190, there is usually a small amount of DC component, so this embodiment uses a two-tap DC notch filter as a leaky barrel filter. More specifically, a The two-junction IIR filter has a transfer curve of the form (please read the precautions on the back before filling this page) •, η— y [n \ al where x is its input signal and y is its output signal, And "It is a filter parameter (32 in this case)-it uses the estimated value of the DC level provided by the AGC control logic circuit 230 to eliminate this DC component. Its AGC control logic circuit 230, This level can be obtained from a look-up table based on some current gain settings.

577197 A7 B7 V. Description of the invention (21) Once the signal is found through strong signal detection or weak signal detection, the fine gain change will be completed. In this preferred embodiment, if consec gainchanges < min gainchanges . And in this preferred embodiment, each fine gain change is completed based on the equation gain_change = adc_desired_size-firpwrl_all (9) conSec_gainchangeS, in terms of strong signal detection, starts at zero As far as weak signal detection is concerned, it starts at two places because it means a rough measurement of the time spent in the AGC, and it takes about two gains to change the time to perform 10% Self-association of windows. It is incremented for each coarse and fine gain change. When no gain change is completed, it will be reset, and strong # detection will not determine that a signal appears. This feature is a more precise gain, or to determine that the gain will be set after the PA has completed the ramp, and to ensure that its AGC has passed a minimum amount of time. The preferred embodiments described above are shown for explanation purposes only, and the invention should not be construed as being so limited. Modifications of the present invention are easily understood by those skilled in the art after reading this specification, and the scope of the present invention and the appended patents also covers such modifications. (Please read the precautions on the back before filling this page) • Order · This paper size applies Chinese National Standard (CNS) A4 specification (210X297 mm) 24 577197 A7 B7 V. Description of the invention (22) Component number comparison 10 ... Heterodyne receiver design 140-IP, 140-Q ... low-pass filter 15 ... antenna 145-IP, 145-Q ... baseband amplifier 20 ... RF (radio frequency) amplifier 170 ... AGC (Automatic Gain Control) unit 25 ... mixing 175-IP ... in-phase mixer 30 ... local oscillator 175-Q ... quadrature mixer 35- " IF (intermediate frequency) amplifier 180 ... local IF oscillator 40 ... band pass filter 185 ... phase shifter 45 ... IF amplifier 190-IP, 190-Q ... A / D converter 50 ... product detector 245-IP, 245-Q ... Leaky barrel filter 55 ... beat frequency oscillator 205-IP, 210-IP , 205_Q, 210-Q… 60… Band-pass amplifier limited pulse response (FIR) filter 65… Analog digital (A / D) converter 215… Power detector 70… AGC (Automatic Gain Control) unit 220… Power Detector 115 ... Broadband antenna 225 ... Autocorrelator 120—RF amplifier 225 ... Autocorrelation processor 125 ... Mixer 230 AGC Control Logic Circuit 130 ... Local RF Oscillator 235 ... Gain Control Generator 135 * " IF Amplifier (Please read the precautions on the back before filling in this page)-Order · This paper size applies to Chinese National Standards (CNS ) A4 size (210X297 mm) 25

Claims (1)

A8B8C8D8 Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs 577197 VI. Application for Patent Scope No. 91107733 Application for Patent Scope Amendment 93 〇1.0.05 1 ·-A method that can be used to estimate whether the received strong signal is a signal in a frequency band based on the power estimation value. This method includes The steps are: input the strong signal it receives; measure the power of the strong signal it receives; provide the strong signal it receives to a filter section; use this filter section to make the strong signal it receives Pass a frequency component in a desired frequency band to obtain a filtered signal; measure the power of the filtered signal; and compare the power measurement value of the strong signal it receives with the power measurement value of the filtered signal to obtain a The received signal is an indication value estimated to be in the frequency band. 2. The method according to item 丨 of the scope of patent application, wherein the power of the strong signal it receives and the power of the filtered signal are measured by obtaining the received strong signals and the filtered signals separately. Sample in the window. 3. The method in item 2 of Shen Qing's patent scope, in which the extreme samples in the measured value of the strong signal it receives and the measured value of its filter and wave signal are not used in the corresponding measurement. 4. The method according to item 3 of the scope of patent application, wherein the maximum amplitude sample within the measurement value of the strong signal it receives and the measurement value of the filtered signal is not used in the corresponding measurement. 5. The method according to item 4 of the patent application, wherein before the step of measuring the power of the strong signal it receives, it includes removing from its input signal «▲ (Please read the notes on the back before filling out this page) 11« — — — — III —. This paper size is in accordance with China's Standard (CNS) A4 specification. ◦ 挪 Nuo Gongai-6 10 15 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 20 Applying for a patent scope DC offset value. 6. The method according to item 4 of the scope of patent application ^ ^ < method, wherein the step of measuring the power it receives is a signal of a person who is different from the step of measuring the power of the filtered signal sample. 7. The method according to item 4 of the patent application, wherein the power measurement of the received signal is completed based on less than one received total short coaching symbol. 8. If the method of claim 4 is applied, the power measurement of the received signal is based on the existence of a coach symbol that includes most sine waves (the slowest frequency positive half cycle), and Each of these majority sine waves has a frequency-an integer multiple of its slowest frequency sine wave. 9. The method according to item 2 of the patent application range, wherein before the step of measuring the power of the strong signal it receives, it includes a step of removing the DC offset value from its input signal. 10. The method of claim 2 as stated in the patent scope, wherein the step of measuring the power of the k number it receives uses a signal sample of a number different from the step of measuring the power of the filtered signal. Π · The method according to item 1 of the scope of patent application, wherein comparing the power measurement value of the strong signal it receives with the filtered signal includes determining whether the power measurement value of its filtered signal is at least the signal it receives A certain part of the power measurement. 12. The method according to item 1 of the patent application scope, wherein before the step of measuring the power of the strong signal it receives, it includes removing from the input signal the paper standard applicable to the Chinese National Standard (CNS) A4 specification (210 X 297 mm) 27 577197 DC offset value steps. 13. The method as described in item 1 of the scope of patent application), which further includes the step of determining the strong signal it receives after β 亥 ′ is not provided, which is a desired signal. 5 丨 4. The method according to item 1 of the range, wherein the strength of the received signal is based on less than the total received short coaching symbols. 15. The method of claiming a patent scope item, wherein the power measurement of the received signal is performed based on one and a half of a total received short coaching symbol. 16 · -A method for estimating whether the input signal is a signal in a frequency band. The method includes the steps of: inputting the input signal; using an analog-to-digital converter to convert the input signal into a digital signal received by 15 ; Determine whether the received digital signal saturates the analog digital converter, and if so, identify the digital signal as a strong signal type; measure the power of the received digital signal; determine the power of the received digital signal Whether it is greater than a desired level, and if so, identify the received digital signal as a strong signal type; provide the received digital signal to a filter section; use this filter section, Make this received digital signal in a Greek ----------- · -Installation (Jing first read the precautions on the back before filling out this page)-^ --------- AWI. Printed by the Intellectual Property Bureau of the Ministry of Economic Affairs and Consumer Cooperatives System ο 2 28 Sodium bismuth male f sores; Putian printed by Κ1 圃 玄 玄 邋 / 广 Δ / 1 昶 技 ΟΊΠ V 9Q7 / Entry, 577197 Employees' Cooperative of Intellectual Property Bureau, Ministry of Economic Affairs The frequency component in the frequency band of the patent application scope is passed to obtain a wave signal to measure the power of the filtered signal; the power measurement value of the received digital signal is compared with the power measurement value of the filtered signal to obtain a The received signal is an indication value of the signal type in a frequency band; and if the received digital number 4 is indicated as belonging to the in-band type and is identified as a strong signal type, the received digital signal is determined as a In-band signals. The method as described in item 16 of the scope of patent application, which further includes the steps of, if saturation is determined, reducing the gain provided by an automatic gain control circuit to an automatic gain control amplification section; and if the digital signal it receives, To be greater than its desired level, the gain provided by its automatic gain control circuit to its automatic gain control amplification section is reduced. 18. The method according to item 16 of the scope of patent application, wherein the power of the digital signals received and the power of the filtered signals are measured by obtaining the received digital signals and the filtered signals separately. Sample in the window. 19. The method according to item 18 of the scope of patent application, wherein the extreme samples in the measured value of the digital signal received and the measured value of the filtered signal are not used in the corresponding measurement. 20. The method according to item 9 of the patent application scope, wherein the maximum amplitude within the measured value of the digital signal it receives and the measured value of the filtered signal 29 Dimensions of this paper _ towel @ National Standard Specification (210 x 297 Gongchu) 3/7197 9¾ 1 ·-5 Repair 1 month The supplementary sample is not used in the corresponding measurement. 21. The method of claim 20, wherein before the step of measuring the power of the digital # received by the method, it includes a step of removing the DC offset value from its input signal. 5 22. The method according to item 20 of the patent application range, wherein the step of measuring the power of the digital number h it receives uses a signal sample of a number different from that of the step of measuring the power of the filtered signal. 23. The method of claim 20, wherein the power measurement of the received digital signal is performed based on less than one received total short coaching symbol. (Please read the precautions on the back before filling out this page) Pack 5 11 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 2 24. If the method of the scope of patent application is No. 23, the power measurement of the digital signal it receives The implementation is based on one half of the total received short coaching code. 25. The method of claim 18, wherein before the step of measuring the power of the digital k number it receives' includes a step of removing the DC offset value from its input signal. 26. The method of claim 18, wherein the step of measuring the power of the digital signal it receives is using a signal sample of a number different from that of the step of measuring the power of the filtered signal. 27. The method of claim 18, wherein comparing the power measurement value of the strong signal it receives with the filtered signal includes determining whether the power measurement value of its filtered signal is at least the signal it receives A certain part of the power measurement. 28. The method of claim 16 in the scope of patent application, wherein Paper Rule (CNS) A4 (297 mm) 577197 93 · 1 · Both Before the step of strong signal power, it includes the step of removing the DC offset value from its input signal. 29. The method of claim 16 in which the power of the received signal is determined based on less than one received total short coaching symbol. 30. The method according to item 29 of the scope of patent application, wherein the power measurement of the received signal is determined based on half of the total received short coaching code. 0 ο 11 5 11 Employee Consumption Cooperative of Intellectual Property Bureau, Ministry of Economic Affairs印 -ΙΪ ο 2 31. If the method of the 16th scope of the patent application, the method further includes the step 疋 'If a signal in a frequency band is determined to exist, a fine automatic gain control adjustment is performed. 32 · —A method for determining the existence of a received digital signal with a strong signal type in an input signal, which includes the steps of: using an analog digital converter to convert the input signal into a received digital signal; measuring this The power of the received digital signal; and whether the power of the received digital # is greater than a desired level, and if so, the received digital signal is identified as its strong signal type. 33. The method according to item 32 of the scope of patent application, which further includes the steps of: if the digital signal received by the method is greater than its desired level, an automatic gain control circuit is reduced to provide an automatic gain control amplification area Gain of segments.丨 丨 I ----- «-Install rtt first read the note on the back? (Fill in this page again) This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) 577197 34. A method as claimed in item% of the patent application, wherein the step of reducing the gain reduces its gain by an amount determined based on its determined power and a predetermined target gain value. 35. The method according to item 32 of the scope of patent application, which further includes the steps of: determining whether the digital signal it receives saturates the analog digital converter, and if so, identifying the digital signal as a strong signal type. 36. The method of claim 35, which further includes the steps of: determining whether the digital signal it receives saturates the analog-to-digital converter; and printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs If the digital signal it receives is determined to saturate the analog-to-digital converter, it reduces the gain provided by an automatic gain control circuit to an automatic gain control amplification section. 37. The method of claim 36 in the scope of patent application, wherein the step of reducing the gain can reduce its gain by a predetermined amount. 38. The method of claim 35, wherein the steps of determining whether the digital signal received by it saturates the analog-to-digital converter include: & ten of the majority of samples it receives The number of times the predetermined saturation threshold is exceeded; and comparing this number with a predetermined saturation count threshold, so that when the predetermined saturation count threshold is exceeded, the digital signal it receives is determined to be an analog-to-digital conversion The device is saturated. The paper size is based on the Chinese National Standard (CNS) A4 specification (2) 0 X 297 public love) (Please read the precautions on the back before filling out this page)-^ --------- AWI. Installation VI. Patent Application 39. A system that can detect signals in the frequency band. This system includes : Filter section, which can filter a received digital signal, so that the frequency of the received digital signal in a desired frequency band can be used to obtain a filtered signal; 5 a power tester, which can measure The power of the filtered signal, and the power of the digital signal it receives, and a control logic circuit, which can determine whether the signal it receives is based on the measured power of the received digital signal and the filtered signal. Is a signal in a frequency band. 10 40. The system claimed in item 39 of the patent scope, wherein the wave filter section includes a finite impulse response filter. 41. The system of claim 39, wherein the filter section includes a decimation filter. 42. The system of claim 39, wherein the filter section 15 includes a low-pass filter. 43. The system of claim 39, wherein the power detector includes separate power detectors that can measure the digital signals it receives and the filtered signals. 44. The system according to item 43 of the patent application range, wherein each of the power detection 20's includes a sampler configured to obtain a sample of a corresponding signal within its window. 45. In the case of the system under item 43 of the patent application, each of the power detectors' does not use samples within the measurement value of its corresponding signal. 46. If the system of item 39 of the patent scope is applied, the power of the filtered signal and the patent coverage rate measurement are made using at least some signal samples derived from the measured power of the signal it receives. 47. If the system of item 39 of the patent application scope, # 中 系 further includes: a 5 DC offset control unit that can remove the 00 offset value of its input signal. For example, the system and system of item 39 of the patent scope, wherein the control logic circuit includes: a device that can determine whether the power of the received digital signal is greater than a desired level, and if so, can identify the reception The digital signal is its strong signal type. W 49. The system according to the patent scope, wherein the steps further include: a device for reducing the gain, which is used for reducing an automatic gain control circuit provided that the digital signal it receives is greater than its desired level; To an automatic gain control the gain of the amplification section. 50. If the system of item 49 of the scope of patent application is applied, the device for reducing the gain is set to 15 when the digital signal received by it is greater than its desired level, so that its gain is reduced-based on its determined power and a predetermined The predetermined amount of gain target value. 51. If the scope of the 48th scope of the patent application, the system further includes:, a device that can determine whether the digital signal it receives converts its analog digital conversion to a 1120 reading sum, and if so, identifies the digital signal as its Strong I signal type. 52. If the system of the scope of patent application No. 51, the tools used to determine | include: First, | Most samples used to count the received digital signal exceeds a predetermined I 34 This paper size applies _ 国 ^ 准 （ CNS) A4 specifications ⑵ " G x 297 public love] 577197 577197 577197 Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs Use most samples of the signal it receives to determine the received signal power level of this received signal; compare its received signal power level with its power level in its frequency band; and when its received signal power level is 'possible' When a desired signal is included, if the increase in the power level in its frequency band is at least proportional to the increase in the received signal power level, it is determined that the received signal does indeed include a desired signal. 】 · If the method is called item 6G of the patent scope, the step of identifying the power level in its frequency band 'uses most but less than all the samples identified as in-band components. 62. = Method of applying for the scope of patent application No. 61, in which the samples identified as being used as a knife in a frequency band have a lower power level than the samples that are identified as being used as a knife in a frequency band but not used quasi. 63. For the method in the 61st scope of the patent application, there are 32 samples, which are identified as frequency components, and these 32 samples are used to determine the power level in their frequency band. 64. The method of claim 60 in the scope of patent application, wherein the step of obtaining the self-correlation measurement value includes the step of removing the 00 offset value from the signal it receives. 65. The method according to item 58 of the scope of patent application, wherein the further steps include determining the power level of the signal it receives; determining the power level of the band component of the signal it receives; comparing the power level of the signal it receives Associated with the frequency band (CNS) of this received signal. Internal power level in the frequency band; and printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs ··· 1111. When the received signal may include a desired signal, if the increase in the power level in its frequency band is at least proportional to any increase in the power level of the received signal, it is determined This received signal does include a desired signal. 66. If the method of applying for the scope of the patent No. 65, the step of obtaining the measured value from the correlation 'includes the step of removing the 0 (: offset value) from the signal received by it. This further includes: determining the internal power level of the components in the frequency band of the received signal. This received signal may include-when the desired signal, if the power level in the frequency band is at least a minimum scale, the received signal is determined. 'It does include a desired signal. 68. The method of claim 67, in which the step of μ its power level in the frequency band uses most but less than all samples identified as components in the frequency band. 69 · If the method of applying for the scope of the patent No. 68, the samples used as components in the frequency band are used, have a lower power level than those of the samples that are marked as in-band knife but not used. 70. If the method of the 68th scope of the patent application '32 of which are identified as frequency components, and the continents in these 32 samples are used to determine their frequency 71. If the method of the scope of patent application for item (1), the step of obtaining the self-correlation measurement value includes removing the offset value from the signal received from it. Please request the patent range A8B8C8D8 Zhiyongyou 2. The method according to item 67 of the patent application scope, wherein the step of obtaining a self-correlation measurement value 'includes a step of removing a DC offset value from a signal it receives. 73_ The method according to item 58 of the scope of patent application, wherein the step of obtaining a self-correlation measurement value 'includes a step of removing a DC offset value from a signal it receives. 7 4 • A system that can be used to detect a desired signal, the system includes: an auto-correlation device that can perform an auto-correlation measurement of a received signal; and a control logic circuit that can be configured: Whether the self-correlation measurement value exceeds a first critical value; when the self-correlation measurement value exceeds its first critical value, it is determined that within a short period of time, the self-correlation measurement value obtained by the signal it receives subsequently, Investigate how many times it has exceeded a second critical value; and when the subsequent measured value exceeds its second critical value, exceeding a predetermined count critical value, it determines the signal it receives, which may include a desired signal. 7 5 · A method that can be used to detect a desired signal. The method includes the steps of: measuring the power level of a received signal; filtering the received signal to produce a substantially received signal at the desired level. A filtered signal composed of components in the frequency range; measuring another power level of the filtered signal; using a power level of its received signal and another power level of its filtered signal to perform a strong signal detection procedure In order to detect its receipt (please read the precautions on the back before filling out this page). 10 15 The signal of strong hope within the patent application signal; and, using the power level of its received signal and another ^ rate level of its filtered signal, to execute the _weak signal_ procedure, and then measure its Weak signal of hope. % The method according to item 75 of the patent application range, wherein before the step of measuring the power level of the received signal ', it further comprises a step of removing the DC offset value from the received signal. 77 · A system that can be used in the automatic gain control for the signal desired by Xian Bu, including: a power detector, which can measure the power of an input signal multiple times, and thus the power of a received signal: A comparison circuit that can compare the power of its input signal at multiple times to determine the existence of the received signal; a filter that can make only the components of the received signal substantially within the frequency range of the desired signal Pass to get a filtered signal; a power detector that can measure another power level of its filtered signal; (please read the note on the back first? Matters before filling out this page) Install ·· Ministry of Economic Affairs Printed by the Intellectual Property Bureau's Consumer Cooperatives. 2 A control logic circuit. The control logic circuit uses this power level and another power level to perform a strong signal detection to measure the content of the received signal. A strong signal of hope, and a weak signal detection is performed to detect a weak signal of hope in the received signal. * 78. A method for performing signal detection, this method includes: obtaining an auto-correlation measurement of a received signal; and this paper size applies Chinese National Standard (CNS) A4 specification (21G x 297 public love) 40 577197 10 Use a majority threshold to operate for these self-correlation measurements. Decide if the signal it receives is likely to be the desired signal. For example, the method in the scope of application for patent No. 78, some of the self-correlation functions Γ are operated at the first threshold value, and other auto-correlation variables are operated at a second threshold value. ⑽ · If the method according to item 78 of the patent application scope, the second critical value is the same as the first critical value. a The method of claim 79, wherein the second critical value is lower than the first critical value. 82. If you apply for the method of 78 items, where you get at least-self-correlation, the measurement system includes: Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs Obtain most samples of the signals it receives; add up the product of the conjugate complex number of each previous sample and the majority of the previous samples obtained by reading the early time; and normalize the sum thus obtained. 83. The method of claiming a patent, further comprising: using most samples of the signals it receives to determine the in-band power level of the in-band components of the received signal; using most samples of the signals it receives To determine the received signal power level of this received signal; compare its received signal! Tiger's power level with its power level in the frequency band; and when its received power level may include-the desired signal If the increase in the power level in its frequency band is at least proportional to = ) 77197 VI § Supplement 10 15 20 Scope of patent application The power level of the received signal medium number 'does indeed include a desired signal. It can be increased to determine this step. For example, the step of applying for the 83rd level of the patent application is to use most but less than = samples of power components in the frequency band. 、 It has been privately divided into in-band and made it: samples that are identified as in-band components and not used are low work; Γ is identified as a method of == _ in the frequency band, of which there are 32 The samples are in-band components, and 28 of these 32 samples are used to determine the power level in their bands. 87. The method of claim 83 in the scope of patent application, wherein the step of obtaining the self-correlation measurement value includes the step of removing the offset value from the signal it receives. 88. = The method of applying for the scope of patent application No. 78, which further includes the steps of determining the power level of its received signal and the in-band power level of its in-band component; comparing the power level of its received signal with The in-band power level of the in-band component of the received signal; and when the received signal may include a desired signal, if the increase in the power level in the frequency band is at least proportional to the power level of the received signal Any increase in accuracy determines that this received signal does include a desired signal. 89. The method according to item 88 of the scope of patent application, wherein the measurement value obtained from the correlation is received (received order 42 X 297 mm) 6. The step of applying for the patent scope includes the step of removing the offset value from the signal it receives. 90. The method according to item 78 of the patent application scope, further comprising: determining the in-band power level of the in-band component of the received signal; and 5 10 5 when the received signal may include a desired signal, if The power level in its frequency band is at least-the minimum scale, it is determined that the received signal does indeed include a desired signal. 91. The method of claim 90 in the scope of patent application, wherein the step of determining the power level in its frequency band uses most but less than all samples identified as components in the frequency band. 92. As for the method of applying for the scope of patent No. 91, the samples identified as being formed in the frequency band and being used have lower power levels than those of the unused samples that are difficult to recognize as being formed in the frequency band. quasi. 93. = Method 91 of the scope of patent application ', of which 32 samples are identified as in-band components, and 28 of these 32 samples are used to determine the power level in their frequency band. 94. The method of claim 91, wherein the step of obtaining a self-correlated measurement value 'includes the step of removing a DC offset value from a signal it receives. • The method according to item 90 of the patent application, wherein the step of obtaining the self-correlation measurement value includes the step of removing the DC offset value from the signal it receives. • If the method according to item 79 of the patent application is applied, the step of obtaining the measured value from the couplet includes removing the offset compensation step from the signal it receives.