TW503630B - Station comprising a receiving circuit for a transmission system working according to a spread spectrum technique and method of determining the start of a pulse - Google Patents

Abstract

This station comprises a system in which information is transmitted in the form of symbols appearing in symbol periods. The station comprises a receiving circuit in which a synchronizing circuit is provided for producing an indication of the start of a symbol. This synchronizing circuit comprises a measuring circuit for measuring the energy of the transmitted signal, a first integration circuit for integrating this energy measurement, a second integration circuit for integrating this energy measurement as a function of the output signal of the first integration circuit. Finally, a threshold circuit produces a start-of-received-symbol signal based on the output signal of the second integration circuit.

Description

503630

-^ ~ The present invention and a workstation including a receiving circuit are-suitable for a system for transmitting information in the form of symbols, the connection 'the workstation is thrown to generate a symbol starting finger ^ sensitive wind blowing circuit includes a further invention And one to determine the start of the symbol. 7 and 7 Synchronization Methods The present invention is applicable to cellular wireless using spread spectrum technology, and is especially suitable for code division multi-directional proximity (CDMi) _ class road. Telephone network industry The problem emerging with this type of system is receiver synchronization

No. must pass phase adjustment to local timing. Therefore, the start of the transmitted symbol is required / received. For more information on this subject, see U.S.A., Non-Exact Decisions 5,712,869. In this patent document, synchronization is achieved by the preamble 俨 V * patent case number 15

The present invention plans to reproduce the synchronization sequence with a large signal. Therefore, this type of work-a first integration circuit-a second integration circuit-simplifies the synchronization and sequence of the receiving station. The station is characterized by measuring the energy of the transmission signal to integrate the energy measurement, to integrate the first product, and the redundant pre-step circuit includes: the quantity, the quantity, and the output signal of the sub-circuit one by one The limit value circuit is used for generating a received symbol start according to the output signal of the second integration circuit. BRIEF DESCRIPTION OF THE DRAWINGS By way of non-limiting example, reference is made to specific embodiments detailed below.

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That is, in these and other drawings of the present invention: Figure Id does not include a diagram of a transmission system of a workstation according to the present invention, Figure 2 shows a diagram of an adaptive chirper in cooperation with a differential demodulator, FIG. 3 shows a series combination of two integrating circuits according to the present invention. FIG. 4 shows the shape of a signal on the input of a differential demodulator. FIG. 5 shows the shape of a signal on the output of a first integrating circuit. The shape of the signal on the output of the second integrating circuit is shown, and FIG. 7 shows a processing circuit diagram for establishing synchronization.

Hiigj Fig. 1 shows a transmission system including a first workstation 1 according to the present invention in communication with a second workstation 2. The workstations 1 and 2 include the transfer parts 丨 丨 and 1 2 ′ and the receiving parts 1 4 and 15 respectively. Pay particular attention to the links established in the transmitting section and receiving section 15. This link transmits symbols and uses three paths (such as T1, T2, and T3. Each symbol is composed of a binary element or a binary element, and the binary element is formed by a chip.) The code CS is interrupted. The spreading code CS is generated by a code generator 21 located at the transmitting end: the same spreading code CS represents that the spreading code is adjusted by the chirp and waver 2 to 2 in the receiving section 15, The filter 22 is located at the output of the first stage 23 of this receiving section 15. The filter 22 is connected after the differential demodulator 25. The following articles may find information reports on components 22 and 25: -"Introduct on to spfead_ 503630" in Proceedings of the Institute of Electrical and Electronics Engineers Meeting, March 1980, Volume 3, pages 328 to 353, V. Description of Invention (3)

Spectrum A-R-t i m u 11 i p a t h Techniques and their-

Application to Urban Digital Radio "by G.L.TURIN. -"An Integrated All Digital Diversity Receiver for Spread Spectrum Communications over Mu 11ipath Fading Channe1s" published by VTC 1 9 94 pages 36 7 to 370 by C. MOULEC and others. Figure 2 shows the structure of these elements. The adaptive filter 2 2 is composed of two transversal filters 3 0 and 31, each transversal filter is assigned to the phases I and Q from the first order 2 3 (which are respectively in phase and quadrature phase) related). Only the filter 30 is shown in detail in the figure. It includes delay elements 32a, 3 2 b, 3 2 c ··· in series, each of which causes a delay equal to one wafer period. The multipliers 35a, 35b, 35c, ..., 35d multiply the various delay elements by the coefficients CL_i, CL_2, CL_3 ... CQ. The adder 38 calculates the sum of the output intensities of the multipliers 35a, 3 5b '3 5c' ... 35d. These coefficient values represent the CS value of the spreading code. These two filters generate an in-phase signal χ2ί and a quadrature signal x2Q. These two signals are respectively transmitted to the differential decomposition consisting of delay lines 4 0 and 4 1 _ 2 5 'to result in a signal equal to one symbol period. delay. The two multipliers 45 and 46 respectively perform a multiplication of the delay value by the value appearing at the input of the differential demodulator 25. Then, the adder 4 9 adds up the results produced by these multipliers to generate a signal A, which for the purpose of overview can be written as A (n) = x2I (nN) .x2I (n) + x2Q (nN). x2Q (n) In this formula, "η " represents the current moment, and" N " represents the length of the delay lines 40 and 4 1 equal to the length of the spreading code, and therefore equals the duration of a symbol

503630 V. Description of the invention (4). The data generated by the modulator 25 are decomposed and processed according to the difference to create useful data in the user circuit 26. Due to multiple paths Ti, T2, T3, and other interference, it is difficult to synchronize the reception of the received data with the spreading code generated by the machine. To assist in synchronization, the synchronization circuit includes (Figure 1):-a first integration circuit 5 2 to integrate the energy measurement,-a second integration circuit 54 to integrate the output signal of the first integration circuit,- A limiting value circuit 26 is configured to generate a received symbol start signal according to the output signal of the second integrating circuit. Therefore, based on the pulse start signal, the synchronization of the receiver can be determined according to the processing circuit 58. FIG. 3 shows the structure of the integrating circuits 52 and 54. The integration of these two integrated circuits produces a value of 25 with the differential demodulator. Since the structures of the integrating circuits 52 and 54 are completely the same, only the integrating circuit 52 is displayed. The integrating circuit 52 includes an accumulator composed of an adder 60 and an accumulation memory 62. The integrating circuit 5 2 can be re-initialized, and then the memory is set to zero under the control of the signal SY. In order to re-initialize the integrating circuit 54, the signal SY is also used, but its re-initialization is due to the effect of the output of the first integrating circuit 52, and an active edge is generated every two active edges of the signal SY. The signal SY is processed by the processing circuit 58 (FIG. 1) to generate synchronization. FIG. 4 shows the shape of the signal A on the output of the differential demodulator 25. Paths T1, T2, and T3 provide associated peaks PI, P2, and P3, respectively, which allow the propagation parameters to not change too quickly. The configuration of the aforementioned correlation peaks PI, P2 and P3

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DUJOJU 5. Description of the invention (5) is used to produce ~ with the μ to produce inch-gamma with the same pole, and the value of SB1 is the same after SB1. Because the symbol SB2 and the symbol are allowed at the same time, the negative crest group is in the state. The symbols connected after it have different values. Figure 5 shows that the first period of two x periods will signal 52 on the 52nd path. The sign symbol resets the accumulator of the first-integration circuit 52 to zero, as shown in the figure above. The figure C shows the signal C appearing on the output of the second integration circuit 54. ::: "period will reset the accumulator of the second integration circuit 54 to: the value of the first; between the two symbol periods, the input of the integration circuit 52, the content of the accumulator of an integration circuit 54 is incremented. Therefore, the change in polarity of the peak to the peak of thinking, will lead to the slope of the curve representing the signal c. Fig. 7 "shows the structure of the processing circuit 58. The processing circuit is formed near a counter, where the counter 80 & D / A signal from 2Hn to a D / 2 + l countdown of 81. The value In is a variable that allows synchronization. The following t = one step, and β is a function of the counter capacity and the synchronization accuracy you want to obtain. When the content crosses a zero value, there will be a confirmation of the active synchronization X signal n ^ Iw some internal mention of non-symbols, and this method authorizes the product knife to re-initialize the path. When the change in the slope BEG is detected, then When the Ibt of the counter passes the register 91, it is simultaneously transmitted to the processing unit 90. In the first step, the processing unit 90 determines the value to discuss, so: If I bt ^ 0, then ib 11 = 0 if 0 $ ibt ^ -2b, then lbtt = Ibt

503630 V. Description of the invention (6) If ~ Ibt $ -2b, then Ibtt = — 2b. Where b represents the standby period reserved before the first expected peak at the beginning of the marker symbol appears. ; Then, the value I bt t can be filtered into the intensity Ibttf as a function of the previous filtering value 1) according to the following equation:

Ibttf = Ibtt · a + (1- a) Ibttf (-1) where α is a filter constant less than 1. Then calculate the value I η, which is the associated value to be used by the countdown counter ...

IbttxT

In: + Γ b where Γ is comparable to the gain of a loop formed by synchronization. If you have not used the 遽 function, then Iη can have the following values: If lbtt = 0, Iη = Γ < If Ibtt = Ibt, then IbtxP -f Γ b If 杲 Ibtt = -2b, then In =-Γ is At the end of the countdown cycle (that is, when the count value reaches D / H $, the value In will be placed in the register 95 so that, after the colony χ) '1, the person-fills in the counter 8 〇

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Claims (1)

503630 Amendment No. 89113989 1 · Contribution of the same circuit points to the integration of the letter value of the electric sign patent change accounted for --Γ, F-::-No vr year b health SL · ι > ^ Come to production 2. Detection U 3 · 窨 ~ No. 4. 4. The symbol is zero. 5. The application includes a method to determine the symbol range of the patent. The first or second steps are as follows: Measure the transmission pulse at one symbol period and at least two symbols. 6. The patent application range includes Number one form to transmit the number start instruction-one measurement-one percent —-one second branch circuit, one limit, one income, such as the application slope, such as the application for the patent period, the first such as the application for the patent number cycle, and the 'Use this ^. Workstation with the left receiving circuit, the system of information' The receiving electric step circuit is characterized by a circuit for measuring a transmission signal, a circuit for integrating the energy circuit, and a function for integrating the energy number, Way to start according to the second number. Workstation of scope item 1: 〇 Work of scope item 1 or 2 The integration circuit is reset to zero. The work of the 1st or 2nd range of the work. The second integration circuit resets to the workstation where the output of the first integration circuit starts with the sense pulse. The signal's energy receiving period is applicable to the workstation during the energy period. The runway is provided with a runway for generating runes, and the synchronization circuit includes: energy, quantity measurement, and quantity measurement as output signals of the first product integration circuit, wherein the limit value circuit station is at every other run station, where at least The second product method is refilled every two zeros and at these reset values. The method is applied as characterized in that the method performs the first integration and the energy performs the second integration. O: \ 65 \ 65305.ptc Page 12 503630 Amendment No. 89113989 6. Scope of patent application-The pulse start is determined by detecting the change in the slope of the output signal obtained through the second integration circuit. 6. The method according to item 5 of the patent application scope, wherein the method includes a re-initialization step for periodically re-initializing the first integration, and for re-initializing the period different from a period for re-initializing the first integration. The second integration of the first integration value. 7 · A transmission system including a workstation such as the scope of patent application item 1 or 2. O: \ 65 \ 65305.ptc Page 13