TWI285981B - Automatic gain control of multiple antenna receiver - Google Patents

Abstract

A method includes amplifying a plurality of received signals, generating a plurality of time domain samples of the amplified signals with at least an analog-to-digital converter, determining at least a candidate power according to root-mean-square (RMS) powers of a first group of symbols received at the receiver antennas, and setting the gain of the amplifier according to a selected candidate power with the processor. The received RMS power for one antenna is determined as the square root of the averaged product of each received symbol and its complex conjugate for all symbols of the first group. The candidate power can be determined considering a subgroup of antennas using an RMS value, an arithmetical mean value, or a geometric mean value of this subgroup.

Description

1285981 IX. Description of the Invention: [Technical Field] The present invention provides a wireless communication system, and more particularly, a gain control of a wireless communication system. [Prior Art] In today's online world, the importance of mobility is increasing day by day. Therefore, the use of wireless local area network (WLAN) is becoming more and more widespread. Division multiplexing, OFDM) is the transmission technology currently used in high-speed wireless local area networks. In a wireless local area network that typically uses the concept of positive-father crossover multiplexing, the maximum data transfer rate per band is 54 Mbps, which is significantly less than the data transfer rate of wired local area networks (up to 100 Mbps/IGbps, even i〇GbpS). ). The technologies used today (such as the specifications of IEEE 802.11a and IEEE 802.11g wireless local area networks) have caused wireless local area networks to have this data transfer rate limit. Please refer to Figure -, Figure - is a block diagram of the conventional wireless area network. In the figure, a conventional wireless local area network 1G is shown, including a capture point (Ac·P〇_2, a first user terminal 14 and a second user terminal i6. Wireless local area network) K) is - face lla or 1 qing view. 11 § no _ domain network class typical _. The capture point 12 includes an _antenna (or antenna pair), and communicates with the (IV) first-user terminal Η and the second user terminal 16; the first user terminal 14 includes an antenna; and the second user terminal includes There are two antennas. At 1285981, point 12 is used. One antenna is used to compare with the first and second cents terminals, and the two antennas are used for the above two antennas. Please refer to the second, the second song - no _ domain network ^ two said (four) ___ towel reward (four), by:: day _ in different frequency bands, the first - user terminal 14 f f with thin 16 to make the H band And the third frequency band, because of the data transmission rate of the wireless area or the network parent band ps, we can know that the first user terminal 14 and the first user terminal 16 have a transfer rate limit of 54 Mbps and just Mbps. It is necessary to increase the number of usable frequency bands and the number of antennas of the user terminal. There is a way to increase the data transfer rate limit of the user terminal. In addition, if the wireless area network! 〇 There are only three available frequency bands, and the four antennas of point 12 have one antenna that cannot communicate with the user. The frequency designation has been set in the IEEE 802.11a and IEEE 8〇2 Ug standards. For example, in the IEEE802.11a-1999 specification, there are 12 frequency bands for the 5Ghz frequency for use =. In the IEEE8G2.11g specification, the 2.4Ghz frequency has The 3 bands are used for communication. It can be seen from the foregoing that the 'prior art' band can only be used for one antenna, so each frequency band has a data transmission rate limit of 54 Mbps. An automatic control gain method for an amplifier of a receiver in a conventional wireless communication system and related circuitry can be found in US Pat. No. 6,363,127 and US Pat. No. 6,574,292. However, the patent does not vacate the receiver with multiple antennas to automatically control the gain and related data in the transmission path of a single frequency band of 1285981. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a method for automatically controlling gain when receiving data in a single frequency band, and using a gain processor to measure the rated power of a short preamble symbol, determine candidate power, and Set the gain of the receiver amplifier. Briefly stated, the present invention discloses a method of automatically controlling the gain of a receiving antenna, the steps comprising: amplifying the plurality of domains using at least - amplification ;; (using at least one analog to digital conversion H electrically connected to the amplification 以Sampling the amplified plurality of signals on the tree domain; determining, based on the rated power of the first symbol group received by the plurality of receiving antennas, using a processor electrically coupled to the analog to digital converter At least - the candidate god; the candidate power of the root thief is set to the gain of the amplifier. [Embodiment] Multi-antenna system: Bit 2, Figure 1 and Figure 2 Figure 3 is a plurality of transmitter antennas and a plurality of receiver antennas Figure 2 illustrates the concept of data transmission and reception in a plurality of transmitter antennas and a plurality of interfaces. When multiple transmission signals are transmitted in multiple channels (such as hll), After the interference between the antennas, the form of the transmitted signal (4) received by the solid is substantially synchronously received. 1285981 ===下__Antenna, send and dry excellent h h hu hn ··· hXM ^21 厶22 ^ 2Μ

Ml κ (i) where h is a channel impulse response, the number of Μ &amp; lines). Shooting &quot;number of lakes (_in the receiver day for each channel impulse response h antenna and receiver antenna, 沁 (4) 矣 ^ 疋 疋 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ To the channel impulse response between the antennas of the first state, the relationship between the channel domain and the received signals is as follows: 々hs + n , (2) where =- contains the received transmissions The vector of the signal [heart γμ] τ, S-series - the vector containing the transmitted signals [SiS2~]τ, and the system containing a plurality of vectors affecting the noise of each receiver (5) · Μ], 1285981 The matrix (1) and the paste system (2) are in the hard acid preparation of the orthogonal frequency division multiplexing wireless local area network. In the τ__, the hair supply-receiver and its use method can be (4) The financial effect of the bribe Daoqi Wei Na (1) (to - use dirty 8G2.Ua and defamation llg standard Orthogonal crossover multi-line network receiver as an example). Please note that if you are familiar with the field I know that in the words of I, I, and reference, A writes the letter of the word ((4)_y ―) and lowercase </ RTI> </ RTI> </ RTI> </ RTI> </ RTI> </ RTI> </ RTI> </ RTI> </ RTI> </ RTI> </ RTI> </ RTI> </ RTI> </ RTI> </ RTI> </ RTI> </ RTI> </ RTI> </ RTI> </ RTI> </ RTI> </ RTI> </ RTI> - a transmitter 3A and a receiver 5. The transmitter receives a transmission data 22, passes through - serial input parallel output interface %, outputs a plurality of transmission signals (four) 'string simple parallel output interface 32 connection domain number The orthogonal frequency division multiplexing mode, each of the positive hopper frequency multiplexing modules comprises an orthogonal frequency division multiplexing transmitter 34, a transmitter RF hardware 36 and a transmitter antenna for transmitting RF signals. The 卯 30 can process the far-end transmission signal 'and transmit it from the antenna %, and transmit it to the receiver 5G via the transmission channel % and the plurality of antennas, as shown in Figure 4, Lin. The device 5G includes a plurality of orthogonal sub-sets and each of the positive-family crossover multiplex modules includes a receiver antenna 5, a receiving frequency 56, and an orthogonal sub-receiver 54, orthogonal Frequency division ^ 54 is used to output signals to a channel compensation module 60 and a pass Channel estimation, ^ · channel complement handle, group 60 connected to - parallel input serial output interface 52, flat input serial output interface 52 round-receive data. Channel compensation module (9) 1285981 = channel estimation module 62 The joint action is used to eliminate the influence of inter-antenna interference, so that the received data is equal to the transmitted data 22. The positive-receiving cross-multiplex receiver 54, the channel compensation module 6〇 and the channel estimation module 62 In the frequency domain, in the part of the frequency domain of the communication system 2, the matrix (1) stinks into one of the following subchannel frequency response matrices:

1U 21,k H〗 2,k · ·· Η nlM,k H22,k * ·· Η n2M,k HM2,k ...H_ (3)

^ For each channel frequency response H, the first and second bits in the first frame: the other represents the receiver antenna 58 and the transmitter antenna 38, which defines the channel, the transmitter antenna The number (also equal to the number of receiver antennas). For example, Hu represents the channel frequency response between the first transmitter antenna and the 38 first receiver antenna 58. The channel frequency response matrix (3) is related to the received transmitted signals and the transmitted signals as follows: Lu (4)

Rn,k=Hk.Sn,k+Nnk, where R is the vector containing the received transmitted signals [Ri n kUM n'k]T, s--containing the vector of the transmitted signals [ Si,n,kS2,n,k..w, 11 1285981 [Nl 'n'k N2,n,k...N]vi,n,k]T, N system contains noise that affects each channel The vector here is neglected, the η-based orthogonal octave multiplex symbol is marked, and the k-series sub-channel is marked. Consider equation (4) .. &quot; A Orthogonal Frequency Division Multiplexer Receiver 54 ^Time Silver Let Orthogonal Money k symbol, and look at the coarse standard n, also two or two positive frequency multiplex symbol The relevant position in time is given the notation η. Ask %, although the receiver 5〇 operates on a single I-known positive-frequency crossover multiplex receiver μ heart h as indicated. In Figure 4, the transmitter 30 and the receiver 1 ^ ^, the factory matrix (3) 'channel compensation module 6 〇 use the channel frequency response matrix (1) to find the received data 23 (ideally equal to the transmission data (2). Accepted, ^ Estimating &quot;Ten Module 62 by comparing the known original transmitted signal with the receiver 5, 4: Breaking the I-estimate # channel frequency response matrix, that is, sending a plurality of known, individual materials (Or with the transmission signal sent), the receiver% compares the received calibration data, and the received calibration data with the known calibration data to determine how, the transmission signal received by the computer, etc. Each subchannel k, the reversible known calibration data matrix, is defined as follows: 12 (5) 1285981 pk

Pl,l,k Pl,2,k · · · P],M,k ^2,l,k ^2,2,k * * · ·· ^2,M,k Pm,u PjvU'k · · · P 1 M, M, k refers to a long preamble symbol Lk (such as the IEEE 802.11a or IEEE 802.11g wireless local area network specification definition), and an example of a reversible linear combination matrix as follows: 〇...〇 (a) c = 01---0 • · · · · · · · · · · · , where 1 = c, (6) _0 0··· 1 &quot;l 1 ··· 1 1 •1 1 . .. 1 1 ω'1 ··· ω-(ΜΜ) (b) c = 1 ω ... • * · • · · ωΜ-] , where (^=丄• . . _1 ωΜ-1 ··· ω(Μ_1)2 Μ ·: ·: ···: ω,-1) ··· ω,-ι)2 (7) ω is an equation 1 + ω +...+ ωΜ-1 = one of the solutions, or

(c) c = CM

Cm/2 C c M/2 M/2 a c M/2 where MCm (8)

Cfl, M system 2 multiple known calibration data matrix (5) and long Ί λ ^ negative sequence 5 旒 and reversible linear combination matrix (6) '(7), or (8) relationship is as follows: (9) 13 1285981 where

Lk is the long preamble symbol. ^The idea is to know the respective calibration of the calibration data matrix (5), the number of receiver antennas, the orthogonal frequency division multiple guards, and the sub-channel k. Calibration data that can form a _ reversible matrix can be used. The above reversible linear combination matrix (4), (7), or (8) is only an example. In addition, when the known calibration data is such that the known calibration data (1) of the composition is less than the combination number Μ2 of the transmitting antenna 38 and the receiver antenna%, the hardware lion reduction and cost can be reduced. Channel estimation 62 estimates the frequency response of the judging according to the equation of the town:

The Hk-subchannel k-estimated channel frequency response matrix (ideally equal to the channel frequency response matrix Hk), and the % system containing the received (4) school-transfer-receiving school material matrix, that is, the The board quasi-beaming matrix pk relays the known calibration data in the form received by the receiver 5 (which has been affected by inter-antenna interference). From equation (10), we can know that if the communication system is added, the interference between the antennas is counted as the known calibration resource 14 1285981 , Pk '. The estimated channel frequency response matrix is the - unit matrix. Here, the received signal is equal to the l field (noise is ignored) in the program (4). In the actual _ sub, the inter-antenna interference = _ estimated contact 62 determines the estimated channel frequency response matrix according to the above equation (10). It is estimated that the r meter module 62 determines the estimated channel frequency by two according to the equation 〇〇), and the channel compensation module 6 〇 uses the estimated channel frequency response matrix to estimate the transmitted signals as described in the following equation: (11 Ideally equal to the square where §, the system - contains a plurality of vectors for estimating the transmission, S in the program (4). Please refer to Figure 4, Figure 5 and Equation (5) to Equation (10). The following is a detailed description of the county letter. The configuration is to transmit read _4 22 so that it contains some of the known calibration data. The matching scale is in accordance with the wire type (5) and the program (9). There are different configuration methods, which will be detailed later. The receiver 30 is configured to transmit the data 22 such that the transmitted signals that are orthogonally divided and multiplexed are transmitted by the transmitter antenna 38 on the -single-band; each of the receiver antennas 58 receives the received signals. Shape transmission (in the form of _ transmission minus the influence of the day-to-day interference), the received transmission signal is sent to the channel estimation module, and the 1285981 channel estimation module receives the transmitted signal from the transmission The received calibration data matrix % is obtained, and the Wei scale is compared with the p = row. In the embodiment k of Figure Wuqing, the channel estimation module 62 includes a generator 64 and a _ matrix multiplier, which is generated as 64 from the received signals. Out of the received calibration data matrix, the matrix multiplier 66 multiplies the received calibration data matrix k by the inverse matrix of the known = matrix Pk to determine the estimated channel frequency response matrix, if a special application is required, the channel estimate Module 62 may additionally include other matrix processing: 2 array inverse (4). Finally, channel estimation pool 62 reaches the estimated channel frequency (4) matrix Hk to channel compensation module (9), as shown by equation (10). Estimated transmission of money, hiding, bribery channel solution response matrix can be placed in the channel material 62 _ road frequency 6 () into the limbs, in the correct situation, the estimated transmission signal in § k will be equal to ~ The transmission signals are in the implementation of the change, we use the inverse matrix of the estimated channel frequency response of the mosquito, and the equation (10) and the equation (丨^ becomes: (10,) (1Γ)

Qk^^1 Pk ^ sn,k =Qk *Rn,k 5 where 4 is the inverse matrix of the estimated channel frequency response matrix ^;k. 16 1285981 In this modified embodiment, we do not need to find the inverse matrix of the estimated channel frequency response matrix as shown in equation (11), but the inverse matrix of the received calibration data matrix ^^ is required. This modified embodiment may be useful in some cases than the foregoing embodiments. Please refer to FIG. 6. FIG. 6 is a block diagram of signals transmitted in the communication system of FIG. Figure 6 illustrates the form of a plurality of signals 7〇 defined in accordance with the IEEE 802.11a or 802.11g s specifications. The leading segment 72 of the signal 70 is used to carry the known calibration data, and the data segment 74 is used to carry the transmitted signals. The composition of the guiding segment 72 and the data segment 74 can be varied depending on the transmitter, where the signal pattern is For example only, other signal modes are also available. Please refer to FIG. 7. FIG. 7 is a block diagram of a wireless local area network according to the present invention. The communication system 20 of the present invention can be utilized in the wireless local area network 8 shown in FIG. 7. The wireless local area network 80 includes a processing point 82, a first messenger terminal 84, and a second messenger terminal 86. A third messenger terminal 88. The capture point 82 includes four antennas and corresponding transmitting and receiving hardware. (Refer to FIG. 4) The first messenger terminal 84, the first messenger terminal 86, and the second messenger terminal 88 all include corresponding transmission and reception hard. Body (also refer to Figure 4). See Figure 8 and Figure 8 is a diagram of the frequency band configuration in the wireless local area network of Figure 7. Unlike the traditional wireless local area network shown in Figure 1, the limited number of bands limits the feed rate. In Figure 8, the data transmission rate is not limited by the number of bands. 17 1285981 The second user terminal 86 and the capture point 82' are according to FIG. 4, &quot;;;;« the point 82 and the first user terminal secret use the channel compensation remainder of the invention (9), the job-_embedded_帛The two antennas of the two gamma, ;;= can share a single frequency band. , automatic gain control:

Referring to Figure 9, Figure 9 is a schematic diagram of the automatic gain control of the receiver 1 in accordance with the present invention. Figure 9 shows the structure associated with the automatic 戦 control in Figure 5 and other previously discussed components, and the channel estimation module 62 is omitted for convenience. In Fig. 9, a gain controller 162 is additionally provided. Each receiver RF hardware 156 includes an amplifier, 158, and an analog digital converter 16A. The gain controller 162 receives the digital signal output by the analog-to-digital converter 并6〇 and calculates an appropriate boost ρ for supply to the amplifier 158 in the 四(4) radio frequency receiver module. The structure and operation of the gain processing state 162 are as follows. I. With reference to relation (2), the signal received at the βth receiving antenna can be expressed by the following expression: m (8)+~(8)' (12) where 18 1285981 β is the number of the receiving antenna, and its value is between 1 and Μβ is the receiving signal of the βth receiving antenna in the time domain, η is the index of an orthogonal frequency division multiplexing symbol, α is the number of the transmitter antenna, 1~Μ, sa is the αth transmission The transmission signal of the antenna in the time domain, hPa is the impulse response of the channel from the ath transmitter antenna to the beta receiver antenna, as in relation (1), ϋβ is the noise affecting the βth receiver, and sshort is Short preamble symbol; When a automatic gain control is performed in accordance with the present invention, a known short-sequence symbol is treated as a transmission signal 'that corresponds to the right side of relation (12). When the short-sequence symbol is used, the receiver 100 can correctly determine the nominal power of the received signal (root-mean-square powers). The thief of the post identifies the Vx under the silkworm fine-level day short-term text Symbol:

(n)-r*(n)/L

(13) where L is the total number of short-sequence symbols, and * is the conjugate complex operation. 19 ^85981 rate $考图十' Figure 10 is the number of antennas and the nominal power derived by relation (13). The straight bar graph represents the total number of antennas with the same power rating. Also + The sum of the number of antennas of all straight bars is the total number of antennas of the receiver 100. The figure also includes any antenna group selected arbitrarily. : For each antenna group that is pre-k, the rated power of the received signal can be combined in the following ways to lie three candidate powers: 1 'This is the square root of the rated power, (14) 2 ' For the arithmetic mean of the rated power, ((5) 6^15^ 'This is the geometric mean of the nominal God. (16) Next, the candidate power is inversely opened by the following method to determine the amplifier. The gain of 158 is Αβ: (17) Αβ ^FJFS ^ =: 1 ~Μ, where

Fo is a target power, and 旯疋 selected candidate power, S = 1, 2 or 3 20 1285981 Please refer to FIG. 11 , the selection method of the z antenna groups can be in any of the following four ways: , all of the receiving antennas; - the receiving antenna's rated power (13) exceeds the first threshold; - the receiving antenna's rated power (13) is lower than the second threshold; or four, the receiving antenna's rated power is Between a preselected range of rated power of all antennas. There are eleven combinations of three candidate powers (14), (15), (16) and four possible antenna groups, ～, ～. Those skilled in the art can decide which combination of simple power (14), (15), (16) and which antenna group to use depending on the particular application. Instead, which candidate power (14), (15), (16) and which antenna group are combined, to set the gain of the amplification n 158, the recording-preset selection rule (for example, selecting the maximum value). Referring to Figure 12, Figure 12 is a flow chart 2〇〇. Flowchart 2 describes the process of performing automatic gain control based on the above. For each receive antenna, the short sequence payout number is received in step 204 and loop checked in steps 2〇8 and 210. Wherein, the rated power is calculated in step 206. As a result, relation (13) is implemented for all antennas and all the information required for Figure 10 and Figure 11 is determined. The step usu calculates the candidate power according to the relations (14), (15) and (16). Once all candidate powers have been calculated, step 224 will determine the candidate power based on the job and set the gain of amplifier 158 according to equation (17). This flowchart · 21 1285981 ? 〆 1 is the implementation in the gain controller 162. • Of course, the above methods and formulas are implemented in gain control (4) 162, such as electronic tabular data or algorithms. Alternatively, in the embodiment, the candidate power of the calculation portion may be selected without the candidate power of all of the leaflets. Furthermore, it is also optional: other suitable ffl numbers can be used, and the short-order text is only the embodiment of the present invention. The present invention provides a method for automatically controlling the benefit of a plurality of orthogonal sub-divisions (four) Wang Moo Cai through a single-Φ frequency reading and receiving. Gain (4) Off to measure the nominal god of the short-term symbol, the candidate power of the bully, and the gain of the receiver amplifier. Therefore, the high-efficiency and stable automatic control gain is realized in a plurality of orthogonal frequency division multiplexing receivers of the county. The above are only the preferred embodiments of the present invention, and all changes and modifications made by the scope of the present invention are covered by the present invention. 0 [Simple description of the diagram] Figure 1 is a block diagram of a conventional wireless local area network. FIG. 2 is a schematic diagram of a frequency band configuration in the wireless local area network of FIG. 1. Figure 2 is a schematic diagram of signal transmission between a plurality of transmitter antennas and a plurality of receiver antennas. Figure 4 is a block diagram of a communication system of the present invention. Figure 5 is a block diagram of the receiver in Figure 4. 22 1285981 Figure 6 is a block diagram of the signals transmitted in the four-way system. Figure 7 is a block diagram of a wireless local area network of the present invention. Figure 8 is a schematic diagram of the frequency band configuration in the wireless local area network of Figure 7. Figure 9 is a schematic diagram of the present invention-automatic (four) receiving ϋ city. Figure 10 is a diagram showing the relationship between the tortoise and the turtle. Figure 10 is another relationship diagram of the number of antennas in Figure 9 versus the rated power of the receiver. Figure 12 is a flow chart of the gain control of the gain processor of Figure 9. The symbol of the schema illustrates the conventional wireless local area network 12, 82 capture points 14, 84 16, 86 20 22 23 24 26 30 32 34 36 the second user terminal communication system of the user terminal transmits the data reception data expected signal transmission Channel inter-channel interference channel transmitter serial input parallel wheel-out interface orthogonal frequency division multiplexing transmitter transmitter RF hardware 23 transmitter antenna receiver parallel input serial output interface orthogonal frequency division multiplexing receiver receiver RF Hardware receiver antenna channel compensation module channel estimation module generator matrix multiplier signal leading segment data segment

Wireless Local Area Network of the Invention Third User Terminal Receiver RF Hardware Amplifier ADC Gain Controller 24

Claims (1)

1285981 X. Patent Application Range: i A method for controlling the gain of a multi-antenna receiver, the antenna receiver comprising a plurality of receiving antennas, the method comprising: simultaneously receiving a plurality of signals through a single frequency band; Amplifying the plurality of signals; sampling the amplified plurality of signals in the time domain; determining at least one candidate power according to a rated power of the first symbol group received by the plurality of receiving antennas; A selected candidate power sets the gain. 2. The method of claim 2, wherein the rated power is obtained by performing a square root operation for each received symbol and a conjugate complex of all symbols of the first symbol group (ah). The first antenna group is all four. The method of claim 3, the receiving antenna. 5. If the method of applying for the third paragraph of the patent scope 蝻一#. T镔di an antenna group receiving antenna /, there is #乂一弟一临限大's rated power. 25 1285981 The method of item 3, wherein the receiving antenna of the first antenna group has a lower rated power than the second threshold. 7. The method of claim 3, wherein the receiving antenna of the first antenna group has a power rating of - preselected to the rated power of all antennas. 8. For the method of item 2 of U-Division, the fourth antenna group is determined by arithmetic mean of the rated power. 9. The method of claim 8, wherein the second antenna group is all cold receiving antennas. For example, the method of claim 8 wherein the receiving antenna of the second antenna group has a rated power greater than a third threshold. 11. The method of claim 8, wherein the receiving antenna of the second antenna group has a rated power that is smaller than a fourth threshold. Lu 12. The method of claim 8, wherein the receiving antenna of the second antenna group has a rated power within a range of power ratings preselected for all antennas. 13. The method of claim 2, wherein the (four) power branch operates on a geometric mean of the rated power to determine a third antenna group for each antenna. The method of claim 13, wherein the third antenna group is the receiving antenna. The method of claim 13, wherein the receiving antenna of the third antenna group has a rated power greater than a fifth threshold. The method of claim 13, wherein the receiving antenna of the third antenna group has a rated power that is smaller than a sixth threshold. 17. The method of claim 3, wherein the receiving antenna of the third antenna group has a rated power of all antennas. 18. If you apply for a patent scope! The method of the item, wherein the set amplifier gain is obtained by dividing a target power by the candidate power. 19. The method of claim 1, wherein the symbol is a short-order symbol in a received signal as defined by ffiEE 8〇2 Ua or 802·11g. 20) a method for controlling gain of a receiver in a multi-antenna system, the antenna system comprising a plurality of receiving modules for simultaneously receiving a plurality of signals through a single frequency band, the plurality of receiving modules comprising a plurality of receiving An antenna, the method comprising: amplifying the plurality of signals using at least one amplifier; and sampling the amplified plurality of signals in a time domain of 27 1285981 using at least one analog to digital converter electrically coupled to the amplifier; Determining at least one candidate power based on a power rating of the first symbol group received by the plurality of receiving antennas, using a processor electrically coupled to the analog to digital converter; and selecting a candidate selected by the processor The power sets the gain of the amplifier. The multi-antenna receiving system includes: a plurality of receiving antennas for receiving a plurality of signals simultaneously through a single frequency band; and a plurality of amplifiers coupled to the corresponding receiving antennas for amplifying the complex number according to a gain a plurality of analog-to-digital converters coupled to the corresponding amplifiers for sampling the amplified plurality of signals in the time domain; a gain controller for receiving the plurality of signals according to the plurality of signals The amount of power 一 of a first symbol group received by the antenna determines at least the candidate power, and the gain of the amplifier is set according to a selected candidate power; and the plurality of interfaces UI, the number of sigma converter. The yoke is obtained by a complex number operation. 23. The system of claim 22, wherein the candidate power is the first antenna group of each antenna. 28 1285981. The system of claim 23, wherein the first antenna group is all of the receiving antennas. 25. The system of claim 23, wherein the receiving antenna of the first antenna group has a rated power greater than a first threshold. 26. The system of claim 23, wherein the receiving antenna of the first antenna group has a rated power that is less than a second threshold. 27. The system of claim 23, wherein the receiving antenna of the first antenna group has a rated power within a range of power ratings preselected for all antennas. 28. The system of claim 22, wherein the candidate power is an arithmetic average of the nominal power to determine a second antenna group for each antenna. 29. The system of claim 28, wherein the second antenna group is all of the receiving antennas. 3. The system of claim 28, wherein the receiving antenna of the second antenna group has a rated power greater than a third threshold. 31. The system of claim 28, wherein the receiving antenna of the second antenna group has a rated power that is less than a fourth threshold. 29 j285981 The system of claim 28, wherein the receiving antenna of the second antenna group has a nominal power rating of the antenna. The system of claim 22 wherein the candidate power is a third antenna group for each antenna based on the average of the nominal force rates. 34. The system of claim 33, wherein the third antenna group is all receive antennas. The system of claim 33, wherein the receiving antenna of the third antenna group has a rated power greater than a fifth threshold. 36. The system of claim 33, wherein the receiving antenna of the third antenna group has a rated power that is less than a sixth threshold. A. The system of claim 33, wherein the receiving antenna of the third antenna group has a rated power within a range of powers preselected in all antennas. 3' The system of claim 21, wherein the set amplifier gain is obtained by dividing a target power by the candidate power. 39. The system of claim 21, wherein the short-sequence symbol in the received signal of the symbol s IEEE8〇211a or 802.11g. 30 1285981 VII. Designation of Representative Representatives: (1) The representative representative of the case is: (9). (2) The representative symbol of the representative figure is a simple description: 54 Orthogonal frequency division multiplexing receiver 60 channel compensation module 156 Receiver RF hardware 158 Amplifier 160 Analog-to-digital converter 162 Gain controller 8. If there is a chemical formula in this case Please reveal the chemistry that best shows the characteristics of the invention.