TWI286891B - Method and device for receiving a packet - Google Patents

Abstract

The present invention provides a single circuit and a method which can identify the WLAN standard of a packet or the modulation type of a packet. The single circuit includes a shift register, N determinators and decision logic. The shift register is configured to receive several periods of the preamble of the packet. Each of the N determinators is configured to determine whether the WLAN standard, or the modulation type, of the packet matches one of the N WLAN standards, or the N modulation types. Decision logic is configured to decide the WLAN standard, or the modulation type, of the packet.

Description

1286891 IX. Description of the Invention: [Technical Field of the Invention] The present invention relates to wireless communication, and more particularly to a method and apparatus for receiving a packet. [Previous Technology The 80Z11 standard developed by the International Electrotechnical Society (OLD EE) includes the wireless local area network (hereinafter referred to as WLAN) standard for the 2_4 GHz and 5 GHz bands. The 802_11b standard defines multiple data rates in the 2_4 GHz band, including 1 Mbps, 2 Mbps, 5.5 Mbps, and 11 Mbps. The 802.11b standard utilizes 1/ys direct sequence spread spectrum (DSSS) preamble coding (preamb|e) and uses 彳彳mHz clock cycles to modulate data. In addition to the data rate of 802.11b, 8〇2_11g defines 6 Mbps, 9 Mbps, 12 Mbps, 18 Mbps, 24 Mbps, 36 Mbps, 48 Mbps, and 54 Mbps in the 2_4 GHz band. Rate and use an orthogonal frequency multiple partitioning technique (OFDM). The preamble encoding contains 1 short period (sh〇ft period) (two _8 periods per time period) and 2 long periods (丨〇ng period), and uses a clock of 20 MHz. The cycle is to modulate the data. Since 802_11b and 802·11g can transmit data using the same frequency band (2 4 GHz), when receiving data, a wireless communication receiver must be able to recognize the WLAN standard and be properly demodulated. Many conventional communication systems include two packet detection circuits to detect two different WLAN standards. These packet detection circuits

Lici 4VIA/04001TW, VIT04-0167TW 5 1286891 The secret code used to receive data, calling the WLAN standard. Feng Xiaoyi knows the technology - packet detection circuit. For example, the private test circuit detects whether the received data is 8 〇 2 bird standard. This path includes a shift register 11G, a delay correlator, a state 15 〇, an adder 170, and a logic device 〇. The measuring circuit Π 10 receives the preamble code 100 of the data. Because the packet detects the 8〇z11b standard, the shift register 11 must have 4〇+1 nodes, each node is at 40 MHz, so the first storage unit 11〇1 and one last The storage unit 11〇3 can store one or two, two corresponding nodes 102, 104 in the adjacent time segment. For example, =: „point 1Q2 is the first node of the fifth short time zone, then the node is the first node of the fourth short time zone. The delay correlator 13〇 performs delay correlation to obtain The previous sequence encodes one of the data moving averages. The slave 150 performs automatic correlation to obtain a conventional power moving average of the previous order code 100. The adder 17 compares the normalized power moving average with this data movement. The averaging logic 190 determines the result of this comparison. According to this comparison, the wireless communication system of the prior art can recognize whether the received data is the 802.11b standard. In order to obtain the data moving average of the preamble encoding, delay association The processor 130 includes seven components 13〇1, 13〇3, and 1313. A first component 1301 performs one of the complement calculations of the node 1〇4, and outputs a complement result 106. A second component 1303 will node 102 multiplies the complement result by 1 ' 6 and outputs a signal 108 to indicate whether the node 1 〇 2 and the node 104 correspond to each other. The so-called correspondence means that the node is in a time zone. Ci 4VIA/04001TW, VITO4-0167T The Iffί of W 6 1286891 H is about to proceed with the sequence phase of node 1Q4 in the segment

ίιΓ8^b S determinate special! r (four), bit temporary storage @ 'for storing some continuation signals 1 (10): ^ 305 the number of storage units is based on the actual bribe and - the fifth component 13 〇 9 is an addition U = = 1311 delays the output signal of the fifth component 13 (10). Components 3 2 1309 and 1311 are used to obtain the preamble = 101. - The seventh element (10) calculates and outputs an absolute value 112 of this capital 101. In order to obtain the preamble code 100, the conventional mobile delay unit 150 has six components 15〇1, 15〇3, 15Ή, a seven-element 1501, and one power value of the node 1〇2 is calculated. The second component 15〇3, the third component 1505, the first quadruple component 15G7, and the fifth component 1509 are used to obtain the power moving average 116 of the preamble encoding 100. Their function 盥 the third secret of the extended surface H 130, the fourth component = the piece 309, the same as the sixth element 1311. A sixth component 1511 is an instantiator for averaging 116 according to a predetermined parameter 118 and outputting a signal 12 〇 to indicate a pre-sequence power moving average. 1 υυι韦 The wireless communication system of the conventional technology needs to be on the other side of the packet as shown in Figure 1.

Lici 4VIA/04001TW, VIT04-0167TW 1286891 circuit to detect whether the data is modulated according to the 802.11g standard. The difference between the two packet detection circuits is the number of storage units in the shift register 11〇. 1 For the 802_11g/〇FDM signal, the number of storage units in the shift register 11 is (32+1) nodes instead of (40+1) nodes, 'because at 8〇2_11g/ The parent-time segment of the preamble encoding of the modulated data in the FDM contains 32 nodes. A disadvantage of the prior art is that two packet detection circuits are required. Those skilled in the art will appreciate that if a wireless communication system needs to recognize three different WLAN standards, three packet detection circuits will be required in accordance with conventional techniques, resulting in increased cost and occupying more IC layout areas. SUMMARY OF THE INVENTION The present invention provides a wireless communication receiver for receiving a packet, the form of which selectively conforms to one of N wireless local area network (WLAN) standards, where 'N is an integer greater than 1, the packet A preamble and a modulation data having a plurality of time segments are included. The WLAN standard can be determined by analyzing the plurality of time segments. The wireless communication receiver includes a device for identifying the packet's WLAN standard and a demodulator for demodulating the modulated data. The device is a single circuit having a shift register, a decider, and a decision logic. This shift register is used to receive the time segment of the previous sequence code. The determiner determines whether the WLAN standard of the packet conforms to one of the N wireless local area network (WLAN) standards according to the time segment of the previous sequence coding.

Lici 4VIA/04001TW, VIT04-0167TW 1286891 and output N first signals to indicate N decision results. The decision logic determines the WLAN standard of the packet based on the N first signals, and outputs a sfl number to indicate a decision result. The demodulator is configured to demodulate the modulated data according to the second signal. This wireless communication receiver can be used to determine 8〇2Hb and 802”1g/〇FDM signals, that is, when N is equal to 2. This decides whether the WLAN standard of this packet conforms to IEEE 802"1b or 1 IEEE 802.11g/〇FDM. According to the above wireless communication receiver, the present invention further provides a method for outputting a demodulated data corresponding to a packet, wherein the form of the packet is selected to be in accordance with the WLAN. The method comprises: a time segment of the preamble coding; identifying, by a single circuit, the wlaN standard of the packet from the N WLAN standards according to the time segment of the previous sequence coding, and generating an identification signal to indicate an identification Resulting; receiving the modulation data; and demodulating the modulation data according to the identification signal. The present invention also proposes an identification circuit for identifying a modulation mode of a packet from N modulation modes. The circuit includes a shift register, a determiner, and a decision logic. This shift register is used to receive the time segment of the previous code. The determiner determines whether the modulation mode of the packet conforms to one of the N modulation modes according to the time segment of the previous sequence coding, and outputs N signals to indicate N determination results. The decision logic determines the modulation mode of the packet based on the N signals.

Lici 4VIA/04001TW, VIT04-0167TW 1286891 variants of this issue 0 receive - the system - the package of the package ί: to: =, the modulation of this packet 'this single - the basis of this packet [Embodiment] In an embodiment, a corresponding packet output is outputted in the form of a packet, and the N-radio preamble codes are received. After the preamble encoding is received, λλ/Γακ^ is used, and according to the previous sequence encoding, the WLAN standard of the packet is identified among the N wireless local area networks, and an identification message is output, which is recognized by the next day. result. In order to perform this identification procedure, the single power = by deciding which of the N-port area network (WLAN) standards of the WLAN, and outputting the respective signals to determine the result of the N decisions. In order to perform this decision procedure, this single circuit j delays the association of the previous code (as shown in step 2〇3) and performs an automatic association of the previous code (as shown in step 2〇5). In step 2〇7, the single circuit determines the packet/LANI standard of the packet according to the N decision signals, and outputs the identification signal. In step 2〇9, the modulation data is received. In step 211, the data is demodulated based on the identification signal. When the single circuit determines whether the WLAN standard of the packet conforms to the old EE 802_11b or the old EE 802.11g/OFDM, step 207

Lici 4VIA/04001TW, VIT04-0167TW 1286891 further includes the steps shown in Figure 3. In step 301, the single circuit determines if the WLAN standard for the packet is 802.11g/OFDM compliant. If yes, proceed to step 303, the single circuit outputs a signal to indicate that the WLAN standard of the packet conforms to 802.11 g/OFDM. If not, proceed to step 305, the single circuit determines whether the WLAN standard of the packet conforms to 802_11b. If yes, then step 307 is performed, and the single circuit outputs a signal to indicate that the WLAN standard of the packet conforms to 802_11b. If not, the WLAN standard representing the packet is neither 802.11b nor 802.11 g/〇FDM, and in step 309, the single circuit outputs a signal to indicate this condition. 4 You are in accordance with an embodiment of the present invention for a wireless communication receiver for performing the steps shown in Figures 2 and 3. This embodiment is particularly useful for identifying whether the WLAN standard for this packet conforms to the old EE 8 or the old EE 802.11 g/〇FDM. The packet has a preamble encoding 4 〇〇 and a modulating variable 402, and the preamble encoding 4 〇〇 has 1Q short time segments. The non-sense receiver includes a circuit 401 and a demodulator 403. This circuit has a WLAN standard of 3?==, and this demodulation requires 3 for this "two η to solve, the circuit fairy contains a shift register - 409, - decision logic 411. Shift temporarily stores a short time period of crying 4〇5 codes. Since the shift register 405 has: a wheel offset at 802.11b, and the round is divided into two outputs 413, 415, and 41.7. 4〇Γ =:) early;, stored in the shift register, a brother,,,, (taP). The output unit 415 is a conventional one-to-be-used to output the first stored in the shift register 405. The output unit 417 is the fourth tenth; The fortieth-called silk output in the memory 405 is stored in the shifting temporary + node. The decider contains two first-off

Lici 4VIA/04001TW, VIT04-0167TW 11 1286891, 407 and 419, and a second correlator 421. The first correlator 407 and the second correlator 421 determine whether the VVLAN standard of the packet conforms to 802.11g/〇FDM by retrieving the first node and the thirteenth node, and output a first signal. 404 to indicate a decision result. The first correlator 419 and the second correlator 421 determine whether the WLAN standard of the packet conforms to 802.11b by retrieving the first node and the forty-first node, and output a first signal 406 to indicate One decides the result. The decision logic 411 determines the WLAN standard of the packet based on the two first signals 404 and 406, and outputs a second signal 408 to indicate a decision result. The demodulator 403 then generates a demodulated data 410 based on the second signal 408. The first correlators 407 and 419 perform the delay association of the previous order codes 400 to obtain a data moving average 412, respectively. The detailed functions and circuit partners of the first correlators 407 and 419 can be the same as the function and circuit configuration of the delay correlator 13 of Fig. 1. The second correlator 421 performs an automatic association of the previous sequence encodings 4 to obtain a normalized power moving average 414, respectively. The detailed function and circuit configuration of the second correlator 421 can be the same as the function and circuit configuration of the autocorrelator 15 of Fig. 1. The determiner 409 further includes two adders 423 and 425. Adder 423 is used to compare this normalized power moving average 414 with this data moving average 412, and then generate a first signal 4〇4. Adder 425 is used to compare this normalized power moving average 414 with this data moving average 416, and then generates a first apostrophe 406. Therefore, the first signal 4〇4 indicates the packet, and the No. 802_11g/〇FDM standard is used for modulation; the first signal 406 indicates whether the packet is modulated according to the 802_11b standard.

Lici 4VIA/04001TW, VIT04-0167TW 12 1286891 Decision logic 411 can be, but is not limited to, implemented with an OR gate, which receives two first signals μ (μ and 406) Optionally, the decision logic "I may contain logic for performing the steps of Figure 3. The decision logic 411 contains a WLAN standard for determining whether the packet conforms to 802.11g/〇 according to the first signal 4〇4. The logic of the FDM. If yes, the decision logic 411 outputs the second signal 4〇8 to indicate that the WLAN standard of the packet is 802_11g/〇FDM. If not, the table logic 411 further includes the first signal 406. Determining whether the WLAN standard of the packet conforms to the logic of the 802 11b. If yes, the decision logic 411 outputs the second signal 408 to indicate that the WLAN standard of the packet is 802.11b. If not, the WLAN representing the packet is rarely The non-802.11g/〇FDM is also not 802_11b, and the decision logic outputs a second signal 408 to indicate this condition. Therefore, the demodulator 4〇3 is demodulated. According to the above, the skilled person is familiar with the above. It can be seen that identifying a package of WLAN standard money It is a secret material that has different time segments of different lengths. Therefore, the present invention can be applied to any viewing device that requires a data modulation mode in a variable modulation mode, as long as the time sections of each modulation mode are different. For the other specific lengths, the circle b shows the method of the present invention, which is a soft π-performation method for the modulation of the N modulation methods. In step 501, the preamble coding is received. π provides a single circuit to determine the modulation mode of the packet. (4) Also 'this early-circuit contains a decider. This decider is used according to this

Lici 4VIA/04001TW, \/ITC) 4_0167TW 13 1286891 The code determines whether the modulation mode of this packet conforms to one of the N modulations, and outputs N signals to indicate N results. : 〇5〇5 'This single circuit determines the packet according to the N signals. § This single circuit determines whether the modulation mode of this packet conforms to direct column spread spectrum (DSSS) or orthogonal frequency multi-segmentation (〇 FDM) The second step 505 further includes the steps shown in FIG. 6. In step 6〇1, the single-circuit determines whether the modulation mode of the packet conforms to the 〇FDM. If yes, proceeding to step 603, the single circuit outputs a signal to indicate that the modulation mode of the device is OFDM. If no, proceed to step 6〇5. This single path determines whether the modulation mode of this packet conforms to DSSS. If so, step 607 'this single-circuit output-signal is performed to indicate the modulation mode DSSS of the packet. Medicine, which means that the modulation of this packet is neither 〇fdm nor DSSS. The circuit configuration for determining whether the modulation mode of the packet conforms to DSSS or 〇FDM is the same as that of circuit 4〇1 shown in FIG. The shift register state 405 is for receiving the time segment of the previous sequence code. Since the first correlator 407 retrieves the first node and the thirteenth node, the first correlator 407 and the second correlator 421 determine whether the modulation mode of the packet conforms to OFDM, and rotates the first signal 404 to Instruct a decision result. The first association 419 and the second correlator 421 determine whether the modulation mode of the packet conforms to the DSSS, and output the first signal 406 to Instruct a decision result. ,

Lici 4VIA/04001TW, VIT04-0167TW 1286891 The timer 411 can contain logic for performing the steps shown in Figure 6. The & Logic 411 contains logic for determining whether the packet variant conforms to OFDM based on the first signal 404. If so, the decision logic state 4 turns the second signal 4〇8 to indicate that the modulation mode of the packet is OFDM. If no, the decision logic unit 41 further includes a logic for determining whether the modulation mode of the packet conforms to the DSSS according to the first signal. Right, '▲, the decision logic 411 outputs a second signal 408 to indicate that the -week mode of the packet is DSSS. If not, the modulation method representing this packet is neither OFDM nor DSSS. Burst, complete - a single - circuit to identify a package of Wla ίί = ί ^, change. This single-circuit contains a constant, and this ^ association 11 and - share the second correlator. This special circuit, in turn, reduces the cost and the distribution of 1C; the hair; the inside: Tian can make various changes and refinements. Therefore, this is subject to the definition of the patent application scope attached. Knowing the moon

S^4VIA/04001TW, VIT04-0167TW 1286891 [Simplified Schematic] FIG. 1 is a packet detection circuit of the prior art; FIG. 2 is a flow chart showing demodulation data obtained from a packet according to an embodiment of the invention. Figure 3 is a flow chart of the decision step in Figure 2; Figure 4 is a circuit diagram of a wireless communication receiver in accordance with an embodiment of the present invention, and Figure 5 is a flow chart showing the identification of a packet in accordance with an embodiment of the present invention. The steps of the modulation mode; and FIG. 6 is a flow chart of the decision steps in FIG. [Major component symbol description] Preamble encoding 100 Data moving average 101 Node 102, 104 Signal 108, 114, 120 Normalized power moving average 116 Shift register 110 Absolute value 112 Predetermined parameter 118 Delay correlator 130 Automatic correlator 150 理慈4VIA/04001TW, VIT04-0167TW 16 1286891 Adder 170 Logic 190 Storage Units 1101, 1103 1313 Components 1301, 1303, 1305, 1307, 1309, 1311 Components 1501, 1503, 1505, 1507, 1509, 1511 Preamble Code 400 circuit 401 modulation data 402 demodulator 403 first signal 404, 406 shift register 405 first correlator 407, 419 second signal 408 decider 409 demodulation data 410 decision logic 411 data moving average 412 Round-out unit 413, 415, 417 Normalized power moving average 414 Second correlator 421 Adder 423, 425 Lici 4VIA/04001TW, ViT04-0167TW 17

Claims (1)

1286891 X. Patent application scope: 1. A wireless communication receiver for receiving a packet, the packet form selectively conforming to one of N wireless local area network (WLAN) standards, and N is an integer greater than 1, The packet includes a preamble and a modulation data, and the wireless communication receiver includes: 'an identification circuit for identifying a WLAN standard of the packet, the identification circuit comprising: a shift register Receiving the preamble encoding; a determinator determining whether the WLAN standard of the packet conforms to one of the n wireless local area networks (WLANs) according to the preamble encoding, and the determining device outputs N a first signal to indicate N decision nodes and a decision logic for determining a WLAN standard of the packet according to the N first signals, and outputting a second signal to indicate a decision result; and a solution And a modulator for demodulating the modulated data according to the second signal. 2_ The wireless communication receiver of claim 1, wherein when N is equal to 2, the determiner determines whether the WLAN standard of the packet conforms to the old EE 8〇2 iib or the old EE 802”1g/〇FDM 〇&quot; 3 a wireless communication receiver, such as a request item, wherein the determiner comprises: N first-correlators (correlat〇r) 'delay-correlation for performing the preamble encoding; and a second correlator For the execution of the pre-coded automatic association (aut〇_correlation) 慈理4VIM) 4001TW, VIT04-0167TW 18 1286891 4_ the wireless communication receiver of claim 2, wherein the decision logic comprises: a first a logic device, configured to determine whether one of the N first signals indicates that the WLAN standard of the packet conforms to IEEE 802e11g/OFDM, and if the decision of the Lth logic is yes, the second signal indicates that the WLAN standard of the packet is The old EE 802.11g/〇FDM; and a second logic device, when the first logic device determines no, determines whether the other first signal indicates whether the WLAN standard of the packet conforms to the old EE 802.11b, if the second The logic determines that yes, then the second It indicates the packet number of the WLAN standard is IEEE 802.11b. 5_ - a wireless communication device for identifying a packet from n WLAN standards, the WLAN standard 'N is an integer greater than 1, the packet containing a preamble encoding, the device comprising a shift register for receiving The preamble encoding, determining, according to the preamble encoding, whether the WLAN standard of the packet conforms to one of the N wireless local area network (WLAN) standards, the determiner outputs N signals to indicate N decision results And a decision logic for determining the WLAN standard of the packet based on the N signals. 6. The wireless communication device of claim 5, wherein when N is equal to 2, the decider determines whether the WLAN standard of the packet conforms to the old ee 802.11b or the old EE 802.11g/OFDM 〇 7. a communication device, wherein the determiner comprises: - N first correlators 'for delay association for performing the preamble encoding; and a second correlator for performing automatic association of the preamble encoding. </ RTI> 4VIA/04001TW, VIT04-0167TW 19 1286891 8. The wireless IT device of claim 6, wherein the decision logic comprises: a first logic device for determining one of the N first signals to indicate the packet Whether the WLAN standard conforms to the old EE 802_11g/OFDM, if the decision of the second logic is yes, the decision logic determines that the Wl7n of the packet is the old EE 802-11g/〇FDM; and not the second logic When the decision of the first logic is no, it is determined whether the other first signal indicates whether the VVLAN standard of the packet meets the old ee = 〇 2 bird, and if the decision of the second logic || is yes, the job decision logic The WLAN standard for packets is the old EE 802.11b. 9_ an identification circuit for identifying a packet from the N modulation modes, wherein the modulation path U is greater than an integer of 1, the packet includes a preamble encoding, and the identification is shifted to a register for receiving the preamble Coding; person # 'According to the pre-order code to determine whether the modulation mode of the packet is in the form of a financial formula, the county records the number of her to indicate the results of the N decisions; and the manner. a decision logic for determining an identification circuit of the modulation of the packet according to the N signals, wherein when N is equal to 2, the determiner is determined to be:; == 2 spread spectrum or 9 identification circuit The determiner includes: a brother-related correlator for performing the delay association of the pre-coded; and a face 4V_4001TW, V-single (four) 16 clear 20 ^ 286891 a second correlator for performing automatic association of the pre-code. Ι2·^ (α 求 求 〇 〇 〇 〇 , , , , , , , α α α α α 识别 识别 识别 识别 识别 识别 识别 识别 识别 识别 识别 识别 识别 识别 识别 识别 识别 识别 识别 识别 识别 识别 识别 识别 识别 识别 识别 识别 识别 识别 识别 识别 识别 识别 识别If the decision is yes, the decision logic determines that the mode of the packet is OFDM; and if the decision of step (8) is no, it determines that the tf ί of the packet is dependent on the DSSS, and if the decision is yes, The decision logic determines that the modulation mode of the packet conforms to the DSSS. 13 probe-packet output-demodulation data method, the form of the packet selectively accepts one of N wireless local area network (WLAN) standards, N is greater than 1^ integer, the packet contains - pre-encoding and a modulation data, ^ square / set contains · (a) receiving the pre-coding; (b) by a single circuit, according to the pre-coding The N toe eight WLAN standard of the packet 'and generates an identification signal to indicate that the second (C) receives the modulation data; and (d) based on the identification signal to demodulate the modulation data. 13 method, wherein step (b) further includes · county shirt conforms to the N wireless ) Wherein the quasi-one, respectively, the wheel of the N decision signal; (f) The decision of the N signals, and determines the packet of the WLA and outputs the identification signal. + 慈慈 4VIA/04001TW, VIT04-0167TW 21 1286891 15. The method of claim 14, wherein when n is equal to 2, the step (b) determines whether the WLAN standard of the packet conforms to the old EE 802.11b or the old EE 802.11g. /〇FDM. 16_ The method of claim 15, wherein the step ((1) further comprises (g) performing a delay association of the preamble encoding; and (h) performing an automatic association of the preamble encoding. 17_A method of claim 15 Step (7) further includes: 0) determining whether one of the N decision signals corresponds to the old EE 80Z11g/〇FDM, and if the decision is yes, indicating that the WLAN standard of the packet is the old EE 802.11g/〇FDM; When the decision of step (i) is no, it is determined whether the other decision signal indicates that the packet corresponds to IEEE 802.11b. If the decision is yes, the WLAN standard indicating the packet is IEEE 802.11b. 18. The party N of the WLAN standard for identifying a packet from the N WLAN standards is an integer greater than 1 'The packet contains a preamble code (p "eamb|e" and a modulation data, the method includes ·· (a) receiving the preamble code; wvib!i consists of - a single circuit, according to which the preamble encoding determines whether the packet conforms to one of the N wireless local area network (WLAN) poles JL and outputs N signals refer to a mosquito knot. Quasi- (c) Determine the change mode of the packet based on the N signals. 19_ The method of claim 18, wherein N is equal to 2 and the N standards are reasonable 4VIA/04001TW, VIT04-0167TW 22 1286891 is 丨EEE 802.11b and IEEE 802_11g/OFDM. The method of claim 19, wherein step (9) further comprises: (d) performing a delay association of the preamble encoding; (e) performing the automatic association of the preamble encoding. 21. The method of claim 19, wherein the step (6) further comprises: (f) determining whether one of the N signals corresponds to 丨eee 2_11g/〇FDM, if the decision If yes, then the wlaN standard of the packet is determined to be IEEE 802.11g/〇FDM; (g) when step (f) If the decision is no, then it is determined whether the other signal corresponds to EEE 802.11b. If the decision is yes, the WLAN standard of the packet is determined to be the old EE 802.11b. 22--A kind of packet is identified from n modulation modes. The method of modulation mode, where N is an integer greater than 1, the packet includes a preamble encoding, the method includes: (a sentence receives the preamble encoding; (b) a single circuit determines a modulation mode of the packet The single circuit includes a determiner, and the determiner determines, according to the preamble encoding, whether the modulation mode of the packet conforms to one of the N modulation modes, and the determiner outputs n signals to indicate N determination results; And (c) determining the modulation mode of the packet according to the N signals. 23. The method of claim 22, wherein when N is equal to 2, the determiner is configured to determine whether the modulation mode of the packet conforms to direct sequence spread spectrum Technology (DSSS) or Orthogonal Frequency Multi-Segmentation (OFDM). ' Lici 4VIA/04001TW, VIT04-0167TW 23 1286891 such as 'Part 22, N-A-Link? 徂ί: This f-container contains : A Guansa crying, execution The delayed association of the uranium code; and the ear (4) for the automatic association of the pre-programmed stone. 5, the method of d71, where step (6) is more included. (d) decide whether or not the N coffee, if Said, _ 二应理慈4VIA/04001TW, VIT04-0167TW 24