TW589812B - Frequency offset estimation for communication systems method and device for inter symbol interference - Google Patents
Frequency offset estimation for communication systems method and device for inter symbol interference Download PDFInfo
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
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- H04L27/00—Modulated-carrier systems
- H04L27/0014—Carrier regulation
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/0014—Carrier regulation
- H04L2027/0044—Control loops for carrier regulation
- H04L2027/0063—Elements of loops
- H04L2027/0065—Frequency error detectors
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Abstract
Description
五、發明說明(1 ) 發明所屬之技術領域 本發明係有關於通訊系統之領域,特別係指一種預估頻率偏移 requency offset)之架構,適用於具有符元 mterfe職e)情形的通道(channel)。 Untersymbol 先前技術 通Λ用的通通’ 4寸別疋無線通訊的通道常常受到通道缺陷如··多 ^(multipath)傳遞以及附加·雜訊的影響。就載波調變的系统而士, =偏移-般是由這類系統中發送器和接收器兩者間震盈器不一_ 弓如妓射頻的行動通訊,還會因摻雜了杜卜勒(DQp㈣偏移而 更為心化。正麵碼接收資訊的重要_在於接收魏碌速的捕捉 頻率及追縱相位,-般絲,大解偏移會產生遠超過接收器快速相 位_的追蹤能力,造I魏效能嚴重的衰減。因此,在接收器解調 之W,如何估計、補償頻率偏移是決定系統效能的重要工作。 目前已有許多以附加白色高斯雜訊(additive white Gaussian n。脱, AWGN)的理想條件為基礎而發展的頻率偏移估計法,但在某些應用 裡’例如多重路徑的環境,接收訊號的失真將會造成相當程度的符元 間干擾(mtersymbol interference,簡稱ISI)。這種現象導致額外的雜訊並 且降低頻率偏移估計的效能,所以在無線通訊中ISI問題特別棘手。 當設計一種預估頻率偏移之架構時,必須解決ISI的存在問題,有 鑑於此,根據在接收訊號上進行的非線性運算,Scott等人提出一種估 冲頻率偏移的演算法,請參考:,,Simultane〇us C1〇ck phase and Fre职㈣yV. Description of the invention (1) The technical field to which the invention belongs The invention relates to the field of communication systems, in particular to an architecture for estimating the frequency offset (requency offset), and is applicable to channels having the symbol mterfe (e) channel). Untersymbol's previous technology The universal communication channel for 4 ”wireless communication is often affected by channel defects such as multipath transmission and additional noise. For carrier-modulated systems, = offset is generally caused by the difference between the transmitter and the receiver in this type of system. Le (DQp ㈣ offset and more heart-shaped. The importance of receiving information in the front code _ lies in receiving Wei Lusu's capture frequency and tracking phase,-like silk, large solution offset will produce far more than the receiver's fast phase _ The tracking ability causes serious degradation of the efficiency. Therefore, how to estimate and compensate for the frequency offset in the demodulated W of the receiver is an important task to determine the system performance. At present, many additional white Gaussian noise n. Off, AWGN) frequency offset estimation method developed based on ideal conditions, but in some applications, such as the environment of multiple paths, the distortion of the received signal will cause a considerable degree of intersymbol interference (Referred to as ISI). This phenomenon causes additional noise and reduces the performance of frequency offset estimation, so the ISI problem is particularly difficult in wireless communications. When designing an architecture for estimating frequency offset, it must be solved ISI is problematic, in view of this, according to non-linear operation performed on the received signal, Scott et al punch frequency offset estimation algorithm is one kind, see: ,, Simultane〇us C1〇ck phase and Fre level ㈣y
Offset Estimation”,IEEE Trans, on Commun·,Vol. 43,ρρ· 2263-2270,Offset Estimation ", IEEE Trans, on Commun ·, Vol. 43, ρρ · 2263-2270,
July 1995。這種架構必須計算傅立葉(F〇urier)轉換,並且基於通道脈衝 響應(impnlseresponse^假設做了一些近似。相對地,Fechte;^人則揭 露一種估計頻率偏移以及獲取通道的演算法,請參考:,,Fast Frame 589812 經濟部智慧財產局員工消費合作社印製 A7 B7 五、發明說明(2 )July 1995. This architecture must calculate the Fourier transform and make some approximations based on the impulse response of the channel (impnlseresponse ^ hypothesis. In contrast, Fechte; ^ reveals an algorithm to estimate the frequency offset and obtain the channel, please refer to : ,, Fast Frame 589812 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs A7 B7 V. Invention Description (2)
Synchronization, Frequency Offset Estimation and Channel Acquisition for Spontaneous Transmission over Unknown Frequency-Selective Radio Channels”,Proc· IEEE PIMRC,pp. 229-233,Sep· 1993。以最大可能 性(maximum-likelihood)的準則為依據,Fechtel的方法掃瞄過接收訊號 的資料段落以實現頻率偏移的估計,但這種架構的運作必須以對收到 的符元及其時序(timing)有所了解為前提。另外,Bahai等人顯示頻率偏 移值能夠藉由通道係數之相位旋轉來估計,請參考:”A Frequency Offset Estimation Technique for Wireless Channels”,in 1997 IEEE Workshop on Signal Processing Advances in Wireless Communications 9 Paris ’ Apr· 1997,pp. 397_4〇〇。Bahai的演算法仍然依賴傳送已知的符 元樣本。Viswanathan等人則發表了 一種稱為最大狀態基礎累計 (maximum state-based accumulation,MSA)估算法,詳見:,,A FrequencySynchronization, Frequency Offset Estimation and Channel Acquisition for Spontaneous Transmission over Unknown Frequency-Selective Radio Channels ", Proc · IEEE PIMRC, pp. 229-233, Sep 1993. Based on the maximum-likelihood criterion, Fechtel The method scans the data segments of the received signal to achieve the frequency offset estimation, but the operation of this architecture must be based on an understanding of the received symbols and their timing. In addition, Bahai et al. Show The frequency offset value can be estimated by the phase rotation of the channel coefficients, please refer to: "A Frequency Offset Estimation Technique for Wireless Channels", in 1997 IEEE Workshop on Signal Processing Advances in Wireless Communications 9 Paris' Apr · 1997, pp. 397_4 〇〇. Bahai's algorithm still relies on transmitting known symbol samples. Viswanathan et al. Published a method called maximum state-based accumulation (MSA) estimation method, see: A Frequency
Offset Estimation Technique for Frequency-Selective Fading Channels55 ^ IEEE Commun. Letters,Vol. 5,pp· 166-168,Apr· 20(U。然這種技術的 運作還是必須先知道收到訊號中的調變資料。 …綜觀上述習知的ISI通道用之估算技術,其缺點為需要高度複雜的 運算,因而難以實現運用在積體電路。 發明内容 本發明之目的是提供一種適用於ISI通道之頻率偏移估計裝置,由 於所需運算之獅度低,非常適合f施於積體電路。 本發明之另-目的是提供一種適用於ISI通且 的符元及其時序為前提之解偏移估計架構。 U 了角午收到 (請先閱讀背面之注意事項再填寫本頁) Φ--------訂 W本種翻於符元肝擾通道之解偏雜計裝置,盆 。包=儲存區、—差分單元、—乘冪運算器、-累加n、提取 益i放料。儲存區具有_單元以串列地輸入一接收取Offset Estimation Technique for Frequency-Selective Fading Channels 55 ^ IEEE Commun. Letters, Vol. 5, pp. 166-168, Apr. 20 (U. However, the operation of this technology must first know the modulation data in the received signal. … Overviewing the conventional ISI channel estimation technology, the disadvantage is that it requires highly complex calculations, which makes it difficult to implement the integrated circuit. SUMMARY OF THE INVENTION The object of the present invention is to provide a frequency offset estimation device suitable for the ISI channel. Since the lion degree of the required operation is low, it is very suitable for applying the integrated circuit. Another object of the present invention is to provide a solution offset estimation architecture that is suitable for ISI communication symbols and its timing. U Received at Jiaowu (please read the precautions on the back before filling in this page) Φ -------- Order W This kind of depolarization miscellaneous meter device, which is turned on the channel of Fuyuan liver disturbance, basin. Bag = storage area , -Difference unit, -power operator, -accumulate n, extract the benefit i and put the material. The storage area has _ units to input in series and receive
本紙張 Α7 Α7 經濟部智慧財產局員工消費合作社印製 五、發明說明(3 ) ----- 取樣相㈣上韻解元*平移m個取樣,如此形成一延遲 八、置/'。I分單元對接收取樣相和延遲取樣相兩者之間進行差 刀運异而仔到—初步值序列。乘冪運算器接收初步值 f =,射P絲數,糾求取初步值序狀乘冪。累加器從轉運 异益輸入初步值序列之乘冪,在相對於接收取樣序列的M,個取樣間, 取^次方轉之總和而得到、加值,而該累加值為複數。角度提 來取得累加值之角度,驗單元進—步將該角度按冲的比例縮 小’错以對接收取樣序列估計其頻率偏移值。 4另^面’本發明還揭露一種由狀態指示器、狀態庫、差分單元、 ^權運'☆以及數個計异單謂構成的頻率偏移估計裝置。狀態指示 =難-㈣符元序列以產生代表符元狀態之狀態訊號,該符元狀態 由一個目前的資料符元和M最近收到的資料符元所定義,其^係通 d^刀佈的長度。狀祕具有輸人—接收取樣序列之第―端、輸入 目則索引之第二端以及輸人上述狀態訊號之第三端,目前索引係盘 1前資料符元相關聯。根據狀態訊號,狀態庫儲存由第二端輸入的目、 刚,引以及由第-端輸入的目前資料符元中之_目前接收取樣,並 =操取和目前資料符元同符元狀態之職先前接收取樣及其關聯之先 月)索引其中,料正整數。差分單元對接收取樣序列中之Μ個目前接 收取樣悲、縣得的同符元狀態之難先前減取樣兩者間進行 差分運异,進而得到一初步值序列。 、&根據與上述Μ個目前接收取樣關聯的目前索引以及與上述同符元 之Μ個先别接收取樣關聯的先前索引之間的索引差,每個計算單 4被柯輸人對應該索引差的初步值序列。此外,每個計算單元最 好此夠包括-累加H、_肖度提取器以及—縮放單元。在相對於接收 取枚序列的Μ’個取樣間,每個累加器取初步值序列之總和,且累加屬 於相同索引差之總和以產生—累加值,而該累加值為複數。每個角度 Γ --------tl--------- C請先閱讀背面之注意事項再填寫本頁jThis paper Α7 Α7 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs. 5. Description of the Invention (3) ----- Sampling phase: rhyme solution element * translation m samples, thus forming a delay 8. Set / '. The sub-unit I makes a difference between the receiving sampling phase and the delayed sampling phase and arrives at the initial value sequence. The power operator receives the preliminary value f =, shoots the number of P filaments, and corrects the preliminary value of the sequential power. Yi input from the transfer accumulator heterologous sequences exponentiation initial value, with respect to the M-sequence reception sampling, between samples, the total rotation of the power take ^ obtained, bonus, and the accumulated value of the plural. The angle is used to obtain the angle of the accumulated value, and the inspection unit further reduces the angle by the proportion of the impulse 'to estimate the frequency offset value of the received sampling sequence. 4 In another aspect, the present invention also discloses a frequency offset estimation device composed of a status indicator, a status library, a difference unit, a weight operator, and a plurality of unique counting terms. Status indicator = Difficult-㈣symbol sequence to generate a status signal representing the status of the symbol. The status of the symbol is defined by a current data symbol and the data symbol received by M recently. length. The state secret has the first end of the input-receiving sampling sequence, the second end of the input target index, and the third end of the above-mentioned status signal. The current index is associated with the data symbol before disk 1. According to the status signal, the status database stores the _current receiving samples of the current data symbols input by the second terminal and the current data symbols input by the-terminal, and = the operation and the current data symbols are the same as the symbol status. Previously received samples and their associated previous months) index, which is expected to be a positive integer. The difference unit performs a differential operation on the M currently received samples in the received sampling sequence, and the difficulty of obtaining the same symbol state. The difference unit is used to obtain a preliminary value sequence. , &Amp; According to the index difference between the current index associated with the above M current receiving samples and the previous index associated with the aforementioned M first receiving samples of the same symbol, each calculation order 4 is indexed by Ke input. Sequence of preliminary values of the difference. In addition, each computing unit preferably includes -accumulating H, _shade extractor, and -scaling unit. Between M 'samples relative to the received fetch sequence, each accumulator takes the sum of the sequence of preliminary values, and accumulates the sum of the difference of the same index to generate a cumulative value, and the accumulated value is a complex number. Every angle Γ -------- tl --------- CPlease read the notes on the back before filling in this page j
本紙家標57^: 4規格(210 297公釐) 589812 五、發明說明(4 提取器用來取得對應累加值之角度,每個縮放單元再將對應的角 以-細子然後輸出作為—初步頻率偏移值,其中該因子係對應= 述索引差,些计异單元產生複數個初步頻率偏移值。加權運管 器接著對這些初步頻率偏移值進行加權平均運算,藉: 列估計其頻賴健。 取才篆序 經濟部智慧財產局員工消費合作社印製57 ^: 4 specifications (210 297 mm) 589812 5. Description of the invention (4 The extractor is used to obtain the angle corresponding to the accumulated value, and each zoom unit then uses the corresponding angle as -spin and then outputs it as-preliminary frequency Offset value, where the factor system corresponds to the above-mentioned index difference, and these different calculation units generate a plurality of preliminary frequency offset values. The weighted transporter then performs a weighted average operation on these preliminary frequency offset values, and estimates the frequency by: Lai Jian. Printed by the Intellectual Property Bureau of the Ministry of Economic Affairs
貫施方式 ,使本發明之上述目的、特徵和優點能更明顯易懂,下文特舉較 佳之實施例,並配合所附圖式,作詳細說明如下: 、乂 本發明揭露—種所謂的「狀態基礎的差分累計(祕㈣ 碰麵alaccumulat腿,簡稱SDA)」演算法來估計頻率偏移,先獅 演异的介紹及其·的鱗推導來開始朗。假設通道的變化夠慢, 所以在觀察期間可將通道視為目定不變,則連續時_接收訊號^表 示為 dO=Ae^e^^g(t~kr)+w(t) k=—oo A代表通道增益且為純量(scaiar) Θ代表相位的偏移 代表角(angular)頻率偏移 dk代表第k個傳送的資料符元(symb()1) g(t)代表綜合發送器、接收器和通道的等效脈衝響應 τ代表符元週期 " w(t)代表附加的複數雜訊 以取樣率=取樣⑹,严_卜接收取樣(received贿㈣序列rW 其中 線Implementation methods make the above-mentioned objects, features, and advantages of the present invention more comprehensible. The preferred embodiments are described in detail below with reference to the accompanying drawings, and are described in detail as follows: 1. The disclosure of the present invention-a so-called " The state-based differential accumulation (secret encounter alaccumulat leg, SDA for short) algorithm is used to estimate the frequency offset. The introduction of the lion performance and its scale derivation will begin. Assuming that the channel change is slow enough, the channel can be regarded as unchanged during the observation period. When continuous, the received signal ^ is expressed as dO = Ae ^ e ^^ g (t ~ kr) + w (t) k = --Oo A represents the channel gain and is scalar (scaiar) Θ represents the phase shift represents the angular frequency offset dk represents the kth data symbol transmitted (symb () 1) g (t) represents the comprehensive transmission The equivalent impulse response of the receiver, receiver, and channel τ represents the symbol period " w (t) represents the additional complex noise at the sampling rate = sampling _, strict_bu receive sampling (received bridging sequence rW where
/1 η' Τ ~Μ/ 1 η 'Τ ~ Μ
Aeibe j(〇d" 卜十. τ' ΜAeibe j (〇d " BU X. τ 'Μ
589812 A7589812 A7
*=-〇〇 Ae e M kg\nkM\+w\n\* =-〇〇 Ae e M kg \ nkM \ + w \ n \
\ + W r Τ λ η ·-— J V M J 其中\ + W r Τ λ η · -— J V M J where
Ω" 表示一個符元週期之角偏移 g[nhg{t\ 代表攸§(t)獲付的離散時間(discrete-time)訊號 Anhw{tjtjL U 丨^代表從w⑴獲得的離散時間訊號 實際上,脈衝響應會被_灿倍符元週期的有限長度, 的情形下,假設 ^ ^]=〇 , V^{〇,l,2r..,(ZM-l)} 倘若+ W啦2,·._’(Μ-1)},則接收取樣序列變成 r[M + /] = AeJseJ^ ^^g[(/ _ k)M + ζ·]+ U 一l τ L J C請先閱讀背面之注意事項再填寫本頁} ·_ 經濟部智慧財產局員工消費合作社印製 其中 X{Sl}i) = AejB Υ^ά^[(ΐ ~ k)M + i] k:卜L 合’而,_ίΓ〜,則定義為第1個符元期間的狀態,也就是符元 由目_貧料符洲固過去的資料符元所形成。卿目關項 I ,可看出僅取決於這些L+1個資料符元。 相同i以及相同狀態的接收取#可拿來去除通道的影響以及估 率的偏移,如果忽略雜訊項,則對於任何的& =\ / 、 在對松+’.]和也μ 4兩者間進行差分運算之後,得 = Αΐ2Μ + i\r%M + z] = .\x(siifi]2 ^ ^Ω " represents the angular offset of a symbol period g [nhg {t \ represents the discrete-time signal paid by § (t) Anhw {tjtjL U 丨 ^ represents the discrete-time signal obtained from w⑴ , The impulse response will be limited by the length of the 灿 can double symbol period. In the case of, suppose ^ ^] = 〇, V ^ {〇, l, 2r .., (ZM-l)} if + W 啦 2, · ._ '(Μ-1)}, then the received sampling sequence becomes r [M + /] = AeJseJ ^ ^^ g [(/ _ k) M + ζ ·] + U-l τ LJC Please read the note on the back first Fill out this page again for matters} · _ Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs where X {Sl} i) = AejB Υ ^ ά ^ [(ΐ ~ k) M + i] k: 卜 L 合 '而 , _ίΓ ~ Is defined as the state of the first symbol period, that is, the symbol is formed by the data symbols of the past_poor material Fu Zhougu. Qingmuguan item I can be seen that it depends only on these L + 1 data symbols. The same i and the same state receive # can be used to remove the influence of the channel and the offset of the estimation rate. If the noise term is ignored, for any & = \ /, in the pair loose + '.] And also μ 4 After performing the difference operation between the two, we get = Αΐ2Μ + i \ r% M + z] =. \ X (siifi) 2 ^ ^
f度適用巾國H家鮮(CNS)A4規格(2if 297公釐) :)哪 12 五、發明說明(6 ) 、 示表示共車厄複數(complex conjugate)運 率偏移的^,因此依下式,角頻率偏移為 η - 1 . 的角度含有頻 Δ/Άλ/ 消 其中缺t—Zl稱為索引差(index difference)。 估管;運作過程是含有雜訊因子的,為了降低雜訊項所造成的 加Ϊ個差分運===置的估算準確度’可在取角度之前累 差分結果針對不同財引同調(not coh⑽幻的因夂上述的 下式計管·川的索―料分別進行累加,故,累加值Κ(Δ/)可由 "° ,對於相同的△/ M-\ 其中’内總和,'-!,於相糊固資料符元的Μ個取樣間結合相同狀 J之'外總和,Σ§'則累加相_丨差〜内總和 表對應索引差△/之累加值。換古之,斜 代 於,)之,,所以頻率偏移估計值可從累(Δ/) 勺累力 W 士ν(Αή ¥出 由於相位迴繞(PhaSeWrap.und)造成的列確性,之角度限 制在π和攸間,使得估計裝置畴析麵只有剛 1用太大差值的△/,以避免可解析的範圍過小 頻率偏移的情形。 k从个此蜃理大 下:將不同差值的△/所得到之頻率偏移估計值進行加權平均運算如 :ΥΑ晴 本紙張尺度適肖t酬家標準(CNS)A4規格⑵g x 29^7^-The f-degree applies to the country ’s domestic fresh (CNS) A4 specification (2if 297 mm) :) Which 12 V. Description of the invention (6), ^ indicates that the transport rate of the complex conjugate is shifted, so it depends on In the following formula, the angular frequency offset is η-1. The angle contains the frequency Δ / Άλ / and the missing t-Zl is called the index difference. Estimation management; the operation process contains noise factors, in order to reduce the addition of a differential operation caused by the noise term === the estimated accuracy of the setting can accumulate the difference results before taking the angle for different financial introductions (not coh⑽) The reason for the magic is that the above-mentioned meter and Chuan's cable are accumulated separately, so the accumulated value κ (Δ /) can be obtained from " °, for the same △ / M- \ where 'internal sum,'-! , The 'external sum' of the same shape J is combined between the M samples of the solid data symbols, and the Σ§ 'accumulates the value of the phase difference, which is the sum of the index difference △ / of the internal sum table. Therefore, the estimated frequency offset can be calculated from the cumulative (Δ /) spoon cumulative force W ± ν (Αή ¥ out of the column accuracy caused by phase wrap (PhaSeWrap.und), the angle is limited to π and Y , So that the domain analysis surface of the estimation device has only △ / with too large difference value to avoid the case where the analyzable range is too small and the frequency offset is small. The reasoning is large: the difference △ / obtained by different The weighted average calculation of the frequency offset estimation value is as follows: ΥΑ 晴 The paper size is suitable for the standard (CNS) A4 specification ⑵g x 29 ^ 7 ^-
▲ ---^-------- (請先閱讀背面之注意事項再填寫本頁) _·▲ --- ^ -------- (Please read the notes on the back before filling this page) _ ·
589812 A7 B7 五、發明說明(7 ) 其中,C(A/)代表對應於索 Δ/ = 1;··. 士 t曰;丄 、差 ,麵的加權係數,並且選擇Δ/臟 曰守,須考罝财述的限制。在今呼仕斗壯士 & ^ 隹°又彳估计裝置時,不但要考慮加權平均運 算的實施複雜程度,而且要气馮催卞Θ運 當的練係數來減少估計的誤差, 取間早的方式叙_相等的權值,或妓加權係數和對應的△/之出 現次數成比例。倘若資料符开床万| & 數可以丨 恤4已知且岐,則加權係 /二t于1 ’不然,用計數器來動態取得各個△/的出現次數, 再應用計數Θ所提供的值來產生加權係數。 當資料符元集合的大小為 <時,可能的符元狀態便達到 <,因 此希望能舰錢態的數量,故可料量”麟 轉接收取樣賴,囉是忽略雜關的卿下,錢料末疋 rR [lM + i] = d] · r[lM + /] 、589812 A7 B7 V. Description of the invention (7) Among them, C (A /) represents the cable corresponding to Δ / = 1; ···· t said; 丄, difference, the weighting coefficient of the surface, and choose Δ / dirty, Restrictions on financial statements must be considered. In today's Hu Shidou fighters & ^ 隹 ° and estimation device, not only must consider the complexity of the implementation of the weighted average operation, but also urge the use of Θ practical training coefficients to reduce the estimation error, take an early Ways to describe _ equal weights, or prostitute weighting coefficients are proportional to the number of occurrences of the corresponding △ /. If the data can be used, the weighting system / 2 t is 1 otherwise, the counter is used to dynamically obtain the number of occurrences of each △ /, and then the value provided by the count Θ is applied. To generate weighting factors. When the size of the data symbol set is <, the possible symbol state reaches < , RR [lM + i] = d] · r [lM + /],
k=l—L 咖+ z] A1· RJ, 其中 ={d;d,L,d;d,L+],...,d:di}=d;.{dii di^(...>^}=J; ^k = l—L coffee + z] A1 · RJ, where = (d; d, L, d; d, L +], ..., d: di} = d;. {dii di ^ (... > ^} = J; ^
由以上得知:將接收取樣序舰她旋轉會導致符元狀祕相同的相 位旋轉,而且旋轉後的狀態成為 I di-L>d]d,_L+x r-,d;d]= ,d:d}_L+] r-,\d\2)It is known from the above that rotating the receiving sampling sequencer will cause the same phase rotation of the symbol element, and the state after rotation becomes I di-L > d] d, _L + x r-, d; d] =, d: d} _L +] r-, \ d \ 2)
R.IR.I
S 就相位移鍵式(phase shift keying,pSK)調變而言,^中的最末項為常 ^所以符元狀態的數目縮減了气倍成為 更普遍的方式是從資料 & _映射函數(mapping funetiQn)而不是共純數雜轉相位。 ,,於展頻(Spread SpeCtrUm)通訊系統,若週期性的展頻碼或展頻波 形和^棚的賴綱,職貞祕可視為脈波卿⑽1se shaPing) 濾=器的一部分而被併入等效的脈衝響應中。由於本發明提出的架構 毋而知逼脈波塑形或通道的脈衝響應,所以本發明同樣能夠應用到展 (cns)a4 (210 X 297 公釐)S As far as phase shift keying (pSK) modulation is concerned, the last term in ^ is constant ^ so the number of symbol states is reduced by a factor of time. The more common way is to use the data & _ mapping function (mapping funetiQn) instead of coherent numbers. In the Spread SpeCtrUm communication system, if the periodic spreading code or spreading waveform and the frame of Lai Gang, the job priesthood can be regarded as a part of the pulse wave filter (1se shaPing) and is incorporated into Equivalent impulse response. Because the proposed structure of the present invention does not know the pulse wave shaping or the impulse response of the channel, the present invention can also be applied to exhibition (cns) a4 (210 X 297 mm)
589812 A7 五、發明說明(9 ) 目前接收取樣及其關聯的目前索引,即r[/2M + z·]和/2,更新相對廡的儲 存區。 接下來,差分單元13〇針對相同符元狀態的4μ + (^7,[/ιΜ + ζ·]兩者 間進行差分(differential)運算,藉以得到一序列的初步值來當作中間資 料。如第1圖所示,差分單元130包括共軛複數運算器132以及複數乘法 器134,共軛複數運算器132對其輸入的每個取樣做運算而產生個先 前接收取樣的共概複數,即〆心+(1;複數乘法器134則編妾於共扼複 數運算器132,一樣是對其輸入的每個取樣來做運算,複數乘法哭134 計算4M + /I和+ 兩者之乘積,如下: 口口 〜二4心·Μ/#Μ,對於1KU,…, 其中,代表初步值序列,且M,為正整數。另一方面,目前索引/2與 先前索引(會被送到減法器190以獲得兩者之索引差,即。第i 圖中,差分單元130以及複數個計算單元14〇之間連接著分配器16〇,根 據索引差△/,分配器160將來自於差分單元13〇的初步值序列〜/轉送到 對應的计异單兀14〇,以此方式,每個計算單元14〇會被許可輸入對應 於當前索引差△/之1^。 〜 參考第3圖,每個計算單元之中包括了累加器343、角度提取器泌 以及縮放單元347。累加器343取初步值序列相對於接收取樣序列咖中 每一資料符元的M,個取樣之間的總和,且累加屬於相同索引差之所有 總和以產生一個累加值。根據本發明,最好能在累加器343之前設置一 乘冪運算器34卜以強化頻率偏移估計裝置進而改善其效能。乘^運算 為、341用來計算每個初步值之p次方乘冪(power): 心M/,心t,對於㈣丄…心 其中,P代表求取乘冪用的冪數且係大於丨之整數,例如,但並 地限定本發明,p二2。按照以上的式子,U為初步值序列之口次方乘 冪形式,所以累加器將(U做雙重加總(加条嶋咖叫以求得589812 A7 V. Description of the invention (9) The current receiving samples and their associated current indexes, namely r [/ 2M + z ·] and / 2, are used to update the storage area of a relatively large amount. Next, the difference unit 13 performs a differential operation on 4 μ + (^ 7, [/ ιΜ + ζ ·]) for the same symbol state, so as to obtain a sequence of preliminary values as intermediate data. As shown in FIG. 1, the difference unit 130 includes a conjugate complex operator 132 and a complex multiplier 134. The conjugate complex operator 132 performs an operation on each of its input samples to generate a generalized complex number of previously received samples, that is, 〆 The heart + (1; complex multiplier 134 is compiled in the conjugate complex number operator 132, and the same is performed on each sample of its input. Complex multiplication cry 134 calculates the product of 4M + / I and +, as follows : 口 口 ~ 二 4 心 · Μ / # Μ, for 1KU,…, where represents the initial value sequence, and M is a positive integer. On the other hand, the current index / 2 and the previous index (will be sent to the subtractor) 190 to obtain the index difference between the two, that is, in the i-th figure, the distributor 160 is connected between the difference unit 130 and the plurality of calculation units 14o. According to the index difference Δ /, the distributor 160 will come from the difference unit 13 〇 preliminary value sequence ~ / forwarded to the corresponding calculation unit 14〇 In this way, each computing unit 14 is allowed to input corresponding to the current index difference Δ / of 1 ^. ~ Referring to Figure 3, each computing unit includes an accumulator 343, an angle extractor, and a scaling unit. 347. The accumulator 343 takes the initial value sequence relative to M of each data symbol in the received sampling sequence, the sum between the samples, and accumulates all the sums belonging to the same index difference to generate an accumulated value. According to the present invention, It is best to set a power operator 34 before the accumulator 343 to strengthen the frequency offset estimation device and improve its performance. The multiplication operation is 341, which is used to calculate the power of p power of each preliminary value (power) : Heart M /, heart t, for ㈣ 丄 ... heart, where P represents the power used to find the power and is an integer greater than 丨, for example, but limits the present invention, p 22 2. According to the above formula U is the power of the initial value sequence, so the accumulator doubles (U
(請先閱讀背面之注意事項再填寫本頁) __--------訂---------線(Please read the notes on the back before filling this page) __-------- Order --------- line
A7A7
589812 累加值 料Σλϊ(〜Λ /=〇 M'-l y Σ(%)Ρ ’則累加了相同*△/的内總和,而_代 差△’之累=。根據本發明’ M,不能大於M,而以M,等於Μ 社弓 然後’將心傳遞給角,提取器345作為上述的中間 角乂土 器345從而取得累加值ΚΔΖ)之角度 Ζρ(Δ/) 月度鈇耳 H:以對應的索:Λ:以及幕數 P'Al ,且—π <ΖΡ(Δ/)<π 其中,"代表對應索引差△/之初步偏移值。 估計裝置裡騎些計算單以4時是求得傭個初步偏移值, 估計裝置錄有-加顧算!! 15㈣來對這鍊步偏移錢行 均㈣ghtedaverage)運算。加權運算器15〇依下列式子 $ 移值取加權平均: 心偏 Ω’Χ^Τ)?°(Δ/)允/ Δ/ 其中,Α代表頻率偏移估計值,而c(A/)表示每個索引差心所對鹿 定加權係數。a此,估計裝置能以前述方式對接收取樣相估^豆 率偏移值。 、消 第4圖所示係根據本發明縮減狀態的頻率偏移估計裝置,其中與第 1圖所標示的相同符號代表類似的元件,於此將不再魏。為達到縮減 符元狀態數目之目的,特別新增了一個共轭裝置·和兩個轉相:置 420、430。共滅置410用來產生目前資料符元之共輛複數,即^轉 相裝置4爾資料符元序列做相位旋轉,並縣轉相過的資料符元序列 本紙張尺度適用巾關家標準(cns)A4規格(21ϋ χ 29γ公爱j589812 Accumulated value material Σλϊ (~ Λ / = 〇M'-ly Σ (%) P 'accumulates the internal sum of the same * △ /, and the accumulation of _generation difference △' =. According to the present invention, 'M, cannot be greater than M, and M, is equal to M She Gong and then 'transmits the heart to the angle, the extractor 345 serves as the above-mentioned intermediate angle earthenware 345 to obtain the cumulative value KΔZ) of the angle Zρ (Δ /) monthly. Ear H: Sum: Λ: and the number of scenes P'Al, and -π < ZP (Δ /) < π where " represents the initial offset value of the corresponding index difference Δ /. Some calculation sheets in the estimation device are used to obtain a preliminary offset value at 4 o'clock. The estimation device records-plus calculation! It is necessary to calculate the chain step offset money in 15 steps. The weighting operator 15 takes the weighted average according to the following formula: $ Shift value: eccentricity Ω ′ × ^ Τ)? ° (Δ /) 允 / Δ / where A represents the estimated frequency offset and c (A /) Represents the weighting coefficient of deer for each index. In this way, the estimation device can estimate the received sample phase offset value in the aforementioned manner. Fig. 4 shows a frequency offset estimation device in a reduced state according to the present invention. The same symbols as those shown in Fig. 1 represent similar components, and will not be described here. In order to reduce the number of symbol states, a special conjugate device and two phase inversions: 420 and 430 are added. The total destruction 410 is used to generate the current complex number of data symbols, that is, the phase rotation of the data symbol sequence of the phase conversion device 4 and the phase rotation of the data symbol sequence of the county. cns) A4 size (21ϋ χ 29γ public love j
ί----------φ--------訂--------」-麵 c請先閱讀背面之注意事項再填寫本頁) ⑽812 A7 五 發明說明(U) 施加於狀態指示器110以接供壯能 料符元序列,丨认‘ 目過的資料符_憎資 人;In ,與目丽貧料符元的共軛複數,兩 者相乘後邮Μ,所賤轉後的符元狀可表示為ί ---------- φ -------- Order -------- "-face c, please read the precautions on the back before filling in this page) ⑽812 A7 Five Inventions (U) Applied to the status indicator 110 to receive the powerful material symbol sequence, and recognize the data symbol _ hate capitalist; In, multiply the conjugate complex number with the beautiful material symbol. After the postal mail M, the symbolic status after the conversion can be expressed as
RJ 鮮餹本的付讀恶。轉姆置42G絲將接收取樣序列做相 二 =目過的接,樣序列物接收取樣序列,制,與目前 貝科付凡的共輛複數’ 4,兩者相乘後的形式,於是 再把轉相過的接收取樣相施加於狀_2㈣—端⑵。假設資 t ,輸細峨,符福的數目可因RJ's fresh copy of Fu Yan. Transmitter sets the 42G wire to receive the sampling sequence as the second phase. The sample sequence receives the sampling sequence, and it is the same as the current complex number of Beco Fufan's. Apply the phase-received received sampling phase to the terminal. Suppose that the asset t is small, and the number of Fufu can be caused by
…現貝t的通Λ系統通常是無法在估算解偏移時得知接收的資料 符兀以及時序資訊’所以需要一種非資料辅助(跡d他地d,簡稱 =DA)型的頻率偏移估計裝置,針對脱通道進行起始的估計。由於無法 得知接收的資料符元,狀態庫12时的解多工器训和多工器細可以刪 除,保留-個移位暫存器來存放接收取樣序列,雖然為第頂中實施 例^化形式’本發明以上所提_則仍^_nda型的頻率偏移估 計裝置。第5圖所示即為本發明的NDA型頻率偏移估 區^差分單湖、乘冪運算器541、累加器543、紐提== $放早兀547。儲存區52〇具有M個單元以串列地輸人接收取樣序列 、,經^上,M個單元,接收取樣序列7如]平移M個取樣而形成延遲取 樣序列 ]在本貫施例中,儲存區520係一種Μ個單元的移位暫存 器。 差分單兀530用來對和+-Μ]兩者間進行差分運算,藉以得到 f列的初步值+]當作中間資料,如圖示,差分單元so由共軛複數 運#為532和複數乘法器534所構成,共軛複數運算器532用來產生延遲 589812 A7 B7 五、發明說明(12 ) 取樣序的共軛複數,即〆[«-M];複數乘法 如 厂[,卜川兩者之乘積,如下: 和 +]二 «厂士 一 Af] 其中’ η代表離散的時間點。角度提取器545可直接取得此中間資料之 角度,但最好是在差分單元530之後加入乘冪運算器541,並且將累加 器543設置在乘冪運算器541以及角度提取器545之間。乘冪運算哭 用來計算來自於差分單元530的每個初步值其?次方乘冪,即(〃[4厂,其 中P為冪數,以产2為例,乘冪運算器541算出每個初步值的平方,如^ 產生一序列的平方初步值: 〇 卜Μ])2,假設ρ=2 當然’本發明所用的乘冪運算器541可適用於阳。累加器⑷從 運异為541輸入’並且取+]的總和以當作累加值: v = z^w /ί=0 其中’累力口值V為複數。換言之,累加值V結合了相對於接收取樣序 的Μ,個制取樣。然後,將ν傳遞給角度提取器545作為上述的 料’角度提取器545從而取得累加值v之角度,即π。縮放σσ 貝 著將/厂按Ι/p的比例縮小,亦即: 接 a… The current Λ system is usually unable to know the received data character and timing information when estimating the solution offset, so it needs a non-data-assisted (track other than d, abbreviated = DA) type frequency offset An estimation device performs initial estimation for the off-channel. Since the received data symbols cannot be known, the demultiplexer training and multiplexer details of the state library at 12 can be deleted, and a shift register is reserved to store the received sampling sequence, although it is the first embodiment ^ In the modified form of the present invention, the _nda-type frequency offset estimation device mentioned above is still used. FIG. 5 shows the NDA-type frequency offset estimation area of the present invention, the difference single lake, the power operator 541, the accumulator 543, and Newty == $ 放 早 伍 547. The storage area 52 has M units to input the receiving sampling sequence in series. After receiving the M units, the receiving sampling sequence 7 is as follows: [translation of M samples to form a delayed sampling sequence] In this embodiment, The storage area 520 is a shift register of M units. The difference unit 530 is used to perform a difference operation between the two and + -M], so as to obtain the preliminary value of the f column +] as intermediate data. As shown in the figure, the difference unit so is operated by the conjugate complex number ## 532 and the complex number Multiplier 534, conjugate complex operator 532 is used to generate the delay 589812 A7 B7 V. Description of the invention (12) The conjugate complex number of the sampling order, namely 〆 [«-M]; The product of the two is as follows: and +] 二 «厂 士 一 Af] where 'η represents a discrete point in time. The angle extractor 545 can directly obtain the angle of this intermediate data, but it is better to add a power operator 541 after the difference unit 530, and set the accumulator 543 between the power operator 541 and the angle extractor 545. The power operation is used to calculate each preliminary value from the difference unit 530? The power of the power is (〃 [4 factory, where P is a power number, taking the output 2 as an example, the power operator 541 calculates the square of each preliminary value, such as ^ to produce a sequence of preliminary square values: 〇 卜 Μ ]) 2, assuming ρ = 2 Of course, the power operator 541 used in the present invention can be applied to yang. The accumulator 输入 inputs ′ from the operation difference to 541 and takes the sum of +] as the accumulative value: v = z ^ w / ί = 0 where ‘accumulate force V is a complex number. In other words, the accumulated value V combines individual samples relative to the received sample sequence M. Then, v is passed to the angle extractor 545 as the aforementioned material 'angle extractor 545 to obtain the angle of the accumulated value v, that is, π. Scaling σσ reduces the size of the / factory by 1 / p, that is, then:
-ZF-ZF
P 經 濟 部 智 慧 財 產 局 員 工 消 費 合 社 印 製 以此方式可以估計得到頻率偏移值Ω"。 綜合以上所述,由於本發明具有相當低的計算複雜度, 容易實施於積體電路晶片之中,再者’本發明提出—種新顆 吊 NDA型鮮偏移料裝置,相#適合錢輯轉偏_初步、 雖然本發明已以一具體實施例揭露如上,然政 °Τ。 發狀技術内容,而並非將本發明狹義地限定於該實施例,任 此技藝者,在不脫咸本發明之精神和範圍内,當可作此、+ $ ' F二d干之更動與潤 張尺度適—用—t國國家標準(CNS)A4 2g^公爱) 589812 經濟部智慧財產局員工消費合作社印製 A7 B7 五、發明說明(13 ) 飾,因此本發明之保護範圍當視後附之申請專利範圍所界定者為準 (請先閱讀背面之注意事項再填寫本頁) Φ--------訂---------P Printed by the Intellectual Property Bureau of the Ministry of Economic Affairs and Consumer Affairs Co., Ltd. In this way, the frequency offset value Ω " can be estimated. In summary, the present invention has a relatively low computational complexity and can be easily implemented in integrated circuit chips. Furthermore, the present invention proposes a new hanging NDA-type fresh offset device, suitable for money series. Deflection_Preliminary, Although the present invention has been disclosed as above with a specific embodiment, the policy is not clear. The technical content of the hair, rather than narrowly limiting the present invention to this embodiment, any person skilled in the art, without departing from the spirit and scope of the present invention, can do this. The scale of the stretch is appropriate—use the national standard of China (CNS) A4 2g ^ Public Love) 589812 Printed by the Consumers ’Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs A7 B7 V. The description of the invention (13) The attached patent application shall be as defined by the scope of the application (please read the precautions on the back before filling this page) Φ -------- Order ---------
16 本紙張尺度適用中國國家標準(CNS)A4規格(210 X 297公爱) 589812 經濟部智慧財產局員工消費合作社印製 A7 B7 五、發明說明(14 ) 圖式簡單說明 第1圖是本發明頻率偏移估計裝置之方塊圖; 第2圖是第1圖中的狀態庫之詳細方塊圖; 第3圖是第1圖中的一計算單元之詳細方塊圖; 第4圖是根據本發明縮減狀態的頻率偏移估計裝置之方塊圖;以及 第5圖是本發明另一實施例之方塊圖。 符號說明 101〜符元狀態之序列; 110〜狀態指示器; 120〜狀態庫; 121〜狀態庫之第一端 123〜狀態庫之第二端; 125〜狀態庫之第三端 130〜差分單元; 132〜共軛複數運算器 134〜複數乘法器; 140〜計算單元; 150〜加權運算器; 160〜分配器; 170〜計數器; 180〜移位暫存器; 190〜減法器; 210〜解多工器; 220〜多工器; 230〜儲存區, 341〜乘冪運算器; 343〜累加器; 345〜角度提取器; 347〜縮放單元; 410〜共軛裝置; 420、430〜轉相裝置 520〜儲存區; 530〜差分單元; 532〜共軛複數運算器; 534〜複數乘法器; 541〜乘冪運算器; 543〜累加器; 545〜角度提取器; 547〜縮放單元; 〜接收取樣序列; 4〜目前資料符元; L〜目前索引。 本紙張尺度適用中國國家標準(CNS)A4規格(210 X 297公釐) (請先閱讀背面之注意事項再填寫本頁)16 This paper size applies the Chinese National Standard (CNS) A4 specification (210 X 297 public love) 589812 Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs A7 B7 V. Description of the invention (14) Brief description of the diagram The first diagram is the invention Block diagram of the frequency offset estimation device; Figure 2 is a detailed block diagram of the state library in Figure 1; Figure 3 is a detailed block diagram of a calculation unit in Figure 1; Figure 4 is a reduction according to the present invention A block diagram of a state-based frequency offset estimation device; and FIG. 5 is a block diagram of another embodiment of the present invention. Symbol description 101 ~ Sequence of symbol states; 110 ~ Status indicator; 120 ~ State library; 121 ~ First end of state library 123 ~ Second end of state library; 125 ~ Third end of state library 130 ~ Differential unit 132 ~ conjugate complex number operator 134 ~ complex multiplier; 140 ~ calculation unit; 150 ~ weighted operator; 160 ~ distributor; 170 ~ counter; 180 ~ shift register; 190 ~ subtractor; 210 ~ solution Multiplexer; 220 ~ multiplexer; 230 ~ storage area, 341 ~ power operator; 343 ~ accumulator; 345 ~ angle extractor; 347 ~ scaling unit; 410 ~ conjugate device; 420, 430 ~ phase inversion Device 520 ~ storage area; 530 ~ differential unit; 532 ~ conjugate complex number operator; 534 ~ complex multiplier; 541 ~ power multiplier; 543 ~ accumulator; 545 ~ angle extractor; 547 ~ scaling unit; ~ receive Sampling sequence; 4 ~ current data symbol; L ~ current index. This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) (Please read the precautions on the back before filling this page)
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US8125961B2 (en) | 2005-10-25 | 2012-02-28 | Qualcomm Incorporated | Four way handshake for robust channel estimation and rate prediction |
TWI499251B (en) * | 2012-12-17 | 2015-09-01 | Mstar Semiconductor Inc | Carrier and sampling frequency offsets estimating method and associated apparatus applied to multi-carrier communication system |
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US8125961B2 (en) | 2005-10-25 | 2012-02-28 | Qualcomm Incorporated | Four way handshake for robust channel estimation and rate prediction |
TWI499251B (en) * | 2012-12-17 | 2015-09-01 | Mstar Semiconductor Inc | Carrier and sampling frequency offsets estimating method and associated apparatus applied to multi-carrier communication system |
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