DEMODULATION METHOD IN WIRELESS TELEMETRY SYSTEMS USING FRAME COMBINING
(19)AUSTRALIAN PATENT OFFICE (54) Title DEMODULATION METHOD IN WIRELESS TELEMETRY SYSTEMS USING FRAME COMBINING (51)6 International Patent Classification(s) H04B ooi/69 (21) Application No: 2003217501 (22) Application Date: 2003.02.24 (87) WIPONo: WO04/075430 (30) Priority Data (31) Number (32) Date 2003/10036 2003.02.18 (33) Country KR 7 (43) Publication Date : 2004.09.09 (43) Publication Journal Date : 2004.10.14 (71) Applicant(s) HAN, Gun-Hee; LEE, Seong-Joo; KIM, Jae-Seok (72) Inventor(s) LEE, Seong-Joo; KIM, Jae-Seok; HAN Gun-Hee (H) Application NoAU2003217501 A1(19)AUSTRALIAN PATENT OFFICE (54) Title DEMODULATION METHOD IN WIRELESS TELEMETRY SYSTEMS USING FRAME COMBINING (51)6 International Patent Classification(s) H04B ooi/69 (21) Application No: 2003217501 (22) Application Date: 2003.02.24 (87) WIPONo: WO04/075430 (30) Priority Data (31) Number (32) Date 2003/10036 2003.02.18 (33) Country KR 7 (43) Publication Date : 2004.09.09 (43) Publication Journal Date : 2004.10.14 (71) Applicant(s) HAN, Gun-Hee; LEE, Seong-Joo; KIM, Jae-Seok (72) Inventor(s) LEE, Seong-Joo; KIM, Jae-Seok; HAN Gun-Hee Disclosed herein is a demodulation method in wireless telemetry systems using frame combining. In detail, this invention is related to the CDMA wireless communication systems, especially a demodulation method by frame combining method which uses time diversity in a wireless measuring instrument that is used for wireless telemetry systems. In transmission data of the present invention, CU(Control Unit) transmits the same frame repeatedly several times and RT(Remote Terminal) combines the transmitted frame, which improve signal-to-noise ratio of signal that is demodulated. Therefore, according to the present invention, there is effect that can minimize RT's hardware complexity and reduce electric power consumption, and reduce production costs of modem. What Is Claimed Is: 1. A demodulation method in wireless telemetry systems using frame combining, in which a control unit transmits frame data repeatedly and a receiver of a remote terminal combines the repeatedly transmitted frame.
2. The demodulation method as claimed in claim 1, wherein the remote terminal uses only one CDMA demodulator, and a frame combiner combines the repeatedly transmitted frame.
3. The demodulation method as claimed in claim 1, wherein the remote terminal uses a plurality of CDMA demodulators, selects only the demodulator that has the maximum energy from the plurality of demodulators for every frame and transmits symbols of the frame demodulated by the selected demodulator to a frame combiner, and the frame combiner combines the repeatedly transmitted frame.
4. The demodulation method as claimed in claim 2 or 3, wherein the frame combiner has registers as many as the number of symbols of the transmitted frame, and combines the transmitted frame in such a manner that it accumulates the repeatedly transmitted frame in each register.
5. The demodulation method as claimed in any one of claims 1 to 3, wherein the <Desc/Clms Page number 10> control unit transmits one pilot channel and a plurality of data channels, makes the frame length of each data channel identical to 1/N of that of the pilot channel, and repeats each data frame N times so that the frame start point of the pilot channel coincides with the frame start point of each data channel.
6. The demodulation method as claimed in claim 5, wherein the frame start point of each data channel must coincide with the frame start point of the pilot channel all the time irrespective of the frame length of each data channel transmitted by the control unit.
7 The demodulation method as claimed in claim 1 or 2, comprising: a first step in which the remote terminal performs PN code synchronization using the pilot channel received from the control unit ; a second step in which the remote terminal judges the frame start point of the pilot channel to start demodulation of a data channel transmitted at that point; a third step in which the remote terminal demodulates data for a predetermined frame length, and then stores the demodulated data in the frame combiner; a fourth step in which the remote terminal accumulates demodulated data of a data channel repeatedly transmitted until a next pilot channel starts in the frame combiner and, combining is finished, outputs final data and initializes internal registers of the frame combiner;STDC0114 and a fifth step of repeatedly performing the second, third and fourth steps. <Desc/Clms Page number 11> 8. The demodulation method as claimed in claim 1 or 3, comprising: a first step in which each of m CDMA demodulators of the remote terminal independently performs PN code synchronization using the pilot channel received from the control unit; a second step in which each of the m CDMA demodulators of the remote terminal independently judges the frame start point of the pilot channel to start demodulation of a data channel transmitted at that point; a third step of selecting the demodulator having the maximum energy from the m CDMA demodulators of the remote terminal; a fourth step in which the selected demodulator demodulates data for a predetermined frame length and then stores the demodulated data in the frame combiner;STDC0406 a fifth step in which the remote terminal repeatedly performs the third and fourth steps for every frame, accumulates demodulated data of a data channel repeatedly transmitted until a next pilot channel starts in the frame combiner and, combining is finished, outputs final data and initializes internal registers of the frame combiner; and a sixth step of repeatedly performing the second to fifth steps.