Wireless communications system, transmitting station, and receiving station

• US 7,783,311 B2
• Filed: 09/09/2004
• Issued: 08/24/2010
• Est. Priority Date: 09/09/2003
• Status: Expired due to Fees

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Takiishi, Kosei, Ohkubo, Shinzo, Suda, Hirohito
• Primary Examiner(s): Pan; Yuwen
• Assistant Examiner(s): AKINYEMI, AJIBOLA A
• Application Number:
  US10/936,527
• Publication Number:
  US 20050054357A1
• Time in Patent Office: 2,175 Days
• Field of Search: 455/502
• US Class Current: 455/502
• CPC Class Codes: H04W 56/00 Synchronisation arrangements
• CPC Class Codes: H04W 74/085 collision avoidance
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A receiving station used in a wireless communication system receives information from one or more transmitting stations. The receiving station comprises a receiving unit (112) configured to receive information containing ID information of a transmitting station, and a data extracting unit (1011) configured to extract the ID information from the received information. Transmit timing sequence acquiring means (2012, 2013 and 2014) of the receiving station estimates a transmit timing sequence (Hs) of the transmitting station based on the extracted ID information. Synchronizing means (2014) of the receiving station brings the receive timing of the receiving station in synchronization with transmit timing of the transmitting station based on the transmit timing sequence.

Claims

1. A receiving station for receiving information from one or more transmitting stations, comprising:

a receiving unit configured to receive information containing a unique value of the transmitting station;

an extracting unit configured to extract the unique value from the received information;

a clock generation unit configured to generate clock information;

a memory configured to store a transmit timing sequence in association with each of the one or more transmitting stations, the transmit timing sequences consisting of a plurality of codes to identify plural different time slots for transmission;

a transmit timing sequence acquiring unit configured to acquire the transmit timing sequence of the transmitting station from the memory based on the extracted unique value;

a control unit configured to determine whether a code value corresponding to a currently focused code number of the transmit timing sequence corresponds to the clock information; and

a synchronizing unit configured to bring receive timing of the receiving station in synchronization with transmit timing of the transmitting station if the code value corresponds to the clock information.

2. The receiving station of claim 1, wherein,

the transmit timing sequence acquiring unit estimates a phase of the transmitting station, and

the synchronizing unit brings the receive timing of the receiving station in synchronization with the transmit timing of the transmitting station based on the estimated phase.

3. The receiving station of claim 1, wherein,

the receiving unit receives information containing phase information of the transmitting station,

the extracting unit extracts the phase information from the received information, and

the synchronizing unit brings the receive timing of the receiving station in synchronization with the transmit timing of the transmitting station based on the extracted phase information.

4. The receiving station of claim 1, wherein the receiving unit performs intermittent receive for receiving information at receive timing corresponding to the transmit timing sequence.

5. The receiving station of claim 1, wherein the receiving unit performs intermittent receive for receiving information at receive timing corresponding to the transmit timing sequence, and performs continuous receive for searching for an unknown transmitting station during a period when the intermittent receive is not performed.

6. The receiving station of claim 5, wherein the receiving unit changes the ratio of the intermittent receive to the continuous receive.

7. The receiving station of claim 1, further comprising:

a correcting unit configured to correct phase information of the receiving station based on reference phase information, wherein

the synchronizing unit brings the receive timing of the receiving station in synchronization with the transmit timing of the transmitting station based on the corrected phase information.

8. The receiving station of claim 1, further comprising:

a reference phase information transmitting unit configured to transmit phase information of the receiving station as reference phase information, wherein

the synchronizing unit brings the receive timing in synchronization with the transmit timing of the transmitting station based on the reference phase information.

9. The receiving station of claim 1, wherein the transmit timing sequence acquiring unit acquires a plurality of transmit timing sequences for the transmitting station.

10. The receiving station of claim 1, wherein,

the control unit determines whether a sum of the code value corresponding to the currently focused code number in the transmit timing sequence and a product (Hs_num_r*Ftime*Ht) is the same as the clock information, where Hs_num_r denotes a transmit timing sequence readout count, Ftime denotes a time length of a frame, and Ht denoting a transmit timing sequence period, and

the synchronizing unit is configured to bring receive timing of the receiving station in synchronization with transmit timing of the transmitting station if the sum is the same as the clock information.

11. A receiving station used in a wireless communications system, comprising:

a receiving unit configured to receive information from transmitting station included in the wireless communications system;

a data extracting unit configured to extract ID information of the transmitting station from the received information;

a clock generation unit configured to generate clock information;

a memory configured to store a transmit timing sequence in association with the transmitting station in the wireless communication system, the transmit timing sequence consisting of a plurality of codes to identify plural different time slots for transmission;

a transmit timing sequence acquiring unit configured to acquire a transmit timing sequence of said transmitting station from the memory based on the ID information; and

a controller configured to determine whether the transmitting station is at transmit timing based on whether a code value corresponding to a currently focused code number of the acquired transmit timing sequence corresponds to the generated clock information and to cause the receiving unit to receive data from the transmitting station if it is at the transmit timing of the transmitting station.

12. The receiving station of claim 11, wherein the transmit timing sequence acquiring unit comprises:

a random value selector configured to select a random value based on the ID information;

a random sequence estimator configured to estimate a random sequence based on the random value; and

a transmit timing estimator configured to estimate the transmit timing sequence based on the random sequence.