Mobile communication terminal

• US 7,039,436 B1
• Filed: 01/12/2000
• Issued: 05/02/2006
• Est. Priority Date: 01/12/2000
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Kakehi, Yuji
• Primary Examiner(s): Maung, Nay
• Assistant Examiner(s): SHARMA, SUJATHA R
• Application Number:
  US09/936,293
• Time in Patent Office: 2,302 Days
• Field of Search: 455/437, 455440-443, 455/502, 455/67.11, 455/136, 455/164.1, 455/182.2, 455/192.2, 455/196.1, 455/525, 455/550, 370/503, 375/362
• US Class Current: 455/525
• CPC Class Codes: H04B 7/022 Site diversity; Macro-diversity using two or more spaced independent antennas H04B7/04
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 48/20 Selecting an access point
• CPC Class Codes: H04W 88/02 Terminal devices

Abstract

A mobile communication terminal includes a receiver (2) receiving a radio waves from a base station, a sampling unit (3) sampling a signal received by the receiver (2), a demodulator (5) demodulating the signal sampled by the sampling unit (3), a selector (4) selecting a most significant cell/sector based on data demodulated by the demodulator (5), using at least two different thresholds, and a path detector (6) detecting a primary path based on the signal sampled by the sampling unit (3). Since the selector (4) selects the most significant cell/sector based on the signal sampled by the sampling unit (3), using at least two different thresholds, it is possible to prevent deterioration of the receiving quality due to frequent transition of the main selector.

Claims

1. A mobile communication terminal comprising:

a receiver receiving a radio wave from a base station;

a sampling unit sampling a signal received by said receiver;

a demodulator demodulating the signal sampled by said sampling unit;

a cell selector selecting a most significant cell/sector based on data demodulated by said demodulator;

a path detector detecting multiple paths based on the signal sampled by said sampling unit; and

a clock generator generating sampling clocks with changed timing by inserting different frequency clocks into the sampling clock based on the cell/sector selected by said cell selector and based on the primary path detected by said path detector, and supplying the sampling clock to said sampling unit.

2. The mobile communication terminal according to claim 1, wherein said clock generator inserts one different frequency clock into the sampling clock to change the timing of said sampling clock.

3. The mobile communication terminal according to claim 1, wherein said mobile communication terminal is a mobile communication terminal employing a code division multiple access system.

4. A mobile communication terminal comprising:

a receiver receiving a radio wave from a base station;

a sampling unit sampling a signal received by said receiver;

a demodulator demodulating the signal sampled by said sampling unit;

a cell selector selecting a most significant cell/sector based on data demodulated by said demodulator;

a path detector detecting multiple paths based on the signal sampled by said sampling unit;

a determining unit detecting a primary path from the multiple paths detected by said path detector, and determining whether said primary path is to be changed or not, based on the states of the forward alignment and backward alignment of said primary path; and

a clock generator generating a sampling clock with changed timing based on a result of the determination by said determining unit, and supplying the sampling clock to said sampling unit.

5. The mobile communication terminal according to claim 4, wherein

said determining unit determines whether the primary path is to be changed or not, by transference of the state between:

a first state that no primary path is present,

a second state that the primary path is in a state of backward protection,

a third state that the primary path is in a fixed state, and

a fourth state that the primary path is in a state of forward protection.

6. The mobile communication terminal according to claim 5, wherein said determining unit transfers the state from the first state to the second state, and determines that the primary path is to be changed when the primary path is detected in the first state.

7. The mobile communication terminal according to claim 5, wherein said determining unit transfers the state from said second state to said third state when the primary path is continuously detected multiple times.

8. The mobile communication terminal according to claim 5, wherein said determining unit transfers the state from said fourth state to said first state when the primary path is not continuously detected multiple times.

9. The mobile communication terminal according to claim 4, wherein said clock generator generates the sampling clock with changed timing based on the primary path determined by said determining unit at regular intervals.

10. The mobile communication terminal according to claim 4, wherein said mobile communication terminal is a mobile communication terminal employing a code division multiple access system.

11. A mobile communication terminal comprising:

a receiver receiving a radio wave from a base station;

a sampling unit sampling a signal received by said receiver;

a cell selector selecting a most significant cell/sector based on signal sampled by said sampling unit, using at least two different threshold; and

a path detector detecting multiple paths based on the signal sampled by said sampling unit.

12. The mobile communication terminal according to claim 11, wherein said selecting unit selects a sector/cell of the maximum receiving level as a new most significant cell/sector when a receiving level of the current most significant cell/sector is smaller than a first threshold, and said maximum receiving level of the sector/cell is equal to or higher than a second threshold which is higher than said first threshold.

13. The mobile communication terminal according to claim 11, wherein said selecting unit selects the cell/sector of the maximum quality of channels as a new most significant cell/sector when a quality of channels of the current most significant cell/sector is worser than a first threshold for a period of a second threshold or more.

14. The mobile communication terminal according to claim 11, wherein said selecting unit selects the cell/sector of the maximum quality of channels as a new most significant cell/sector when a difference between the maximum quality of channels of the sectors and the quality of channels of the current most significant cell/sector is higher than a first threshold for a period of a second threshold or more.

15. The mobile communication terminal according to claim 11, wherein said mobile communication terminal is a mobile communication terminal employing a code division multiple access system.