Multiple access method for sharing pseudo-noise code by time division transmission in wireless telemetry system

• US 20040233873A1
• Filed: 03/20/2004
• Published: 11/25/2004
• Est. Priority Date: 09/20/2001
• Status: Abandoned Application

• Current Assignee: Yonsei University, Zethos Company Limited
• Original Assignee: Yonsei University
• Inventors: Kim, Jae-Seok, Han, Gun-Hee, Lee, Hwang, Kim, Kyung-Duk, Choe, Kun-II, Lee, Seong-Joo
• Application Number:
  US10/490,527
• Publication Number:
  US 20040233873A1
• Time in Patent Office: Days
• US Class Current: 370/335
• CPC Class Codes: G08C 17/02 using a radio link

Abstract

Disclosed is a multiple access method for sharing pseudo-noise code by time division transmission in wireless telemetry system, which transmits same time information from a CU (Control Unit) to all RT (Remote Terminal), and each RT transmits data by time division using the time information provided by the CU. Also, each RT decides the respective transmission time using the time information provided by the CU. After each RT transmits data by time division, if the transmitted data has an error, each RT transmits data by time division in repsonse to the retransmission request of the CU.

Claims

1. A multiple access method for sharing a PN code by time division transmission in a wireless telemetry system, in which a plurality of remote measuring terminals (RTs) wirelessly send measured data to a single central processing unit (CU), the method comprising steps of:

1) the CU'"'"'s transmitting time information to all of the RTs, so that the RTs can perform time division transmission, and

2) the RT'"'"'s demodulating the time information from the CU, and transmitting measured data during transmission time assigned to the RT, while stopping transmission during time not assigned to the RTs.

2. The method of claim 1, wherein

the step 1) further comprises a step of the CU'"'"'s transmitting control information data to the plurality of RTs, by using a single PN code, and

the step 2) further comprises a step of the RT demodulating data transmitted from the CU for a given time, and performing synchronization against the PN code transmitted from the CU.

3. The method of claim 1, further comprising steps of:

if errors are found in data that the RT transmits, the CU transmitting to the RT request for re-transmission, and

the RT'"'"'s re-transmitting re-measured data to the CU.

4. The method of claim 1, wherein the RT'"'"'s data transmission time is determined by following equations:

5. A multiple access method for sharing a PN code by time division transmission in a wireless telemetry system, in which a plurality of remote measuring terminals (RTs) wirelessly send measured data to a single central processing unit (CU), the method comprising steps of:

1) when the RT is initially installed to the wireless telemetry system, the RT'"'"'s synchronizing the K number of PN codes transmitted from the CU by demodulating a pilot channel and a time information channel broadcast from the CU, and setting a time information in the CU,

2) the RT'"'"'s checking whether or not the set time at the step

     1) is pre-determined RT enable time, and, if it is not the RT enable time, electricity supply being blocked to power the RT off, otherwise, measured data being transmitted to the CU by the RT in a manner of time division, using the K number of PN codes,

3) after the RT transmitting the measured data to the CU, the RT'"'"'s going into a demodulation waiting state for given times, and re-transmitting re-measured data to the CU when the RT receives from CU a request for re-transmission, otherwise, RT'"'"'s going into a disabled (or sleep) state,

4) repeating the step

     3) by the RT, using an internal timer in the RT.

6. The method of claim 5, wherein the RT enable time is determined by following equations:

7. The method of claim 5, wherein the number of PN codes, K, is one.

8. The method of claim 5, wherein the time information channel of the step 1) comprises a total of 11 bits, comprising 5 bits for a minute and 6 bits for a second characterized in that 64 seconds corresponds to 1 minute.

9. The method of claim 5, wherein the RT enable time of the step 2) includes a frame transmission time required for data transmission from the RT to the CU, and a demodulation wait time required for the RT to demodulate data transmitted from the CU to verify whether or not there are errors in the transmitted data.

10. The method of claim 5, wherein the data transmitted from the RT to the CU comprises a preamble for synchronizing with PN code from the RT, a pilot symbol for estimating data channels, a cyclic prefix for synchronizing a frame transmitted from the RT, and an information data measured by the RT using various sensors.

11. The method of claim 10, wherein the cyclic prefix is made by copying the lower 8 bits of the information data.