US 2003/0169702 A1Published application

Apparatus and method for generating reference timing in a CDMA mobile communication system

AssigneeSamsung Electronics Co., Ltd.

InventorsDong-Ryeol Ryu, Joo-Kwang Kim, Kwang-Man Ok, Chae-Man Lim, Seong-Ho Hur

Life of this patent

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Abstract

A cell search apparatus and method in a W-CDMA mobile communication system. The cell search apparatus and method performs a first cell search step, a second cell search step, and a third cell search step using a slot count value and a lower count value, counted by an index counter after being initialized upon power up of a UE (User Equipment), thereby determining a scrambling code for a Node B. Further, the cell search apparatus and method manages neighboring Node Bs by performing a multipath search.

Claims22

Dependent claims

A method for performing a cell search by receiving from a Node B a primary synchronization channel signal transmitted with as many chips as a predetermined chip length at a beginning of each slot, a secondary synchronization channel signal overlapping with the primary synchronization channel signal, being transmitted while maintaining orthogonality with the primary synchronization channel, and a common pilot channel signal scrambled by a unique scrambling code, a one-frame length of the common pilot channel signal being equal to one period of the scrambling code, each frame being comprised of a predetermined number M of slots each having a predetermined chip length N, in a UE (User Equipment) for a W-CDMA (Wideband Code Division Multiple Access) mobile communication system, the method comprising the steps of:

counting an index count value within a range of a one-frame length by a period shorter than or equal to the predetermined chip length, after being initialized at a predetermined time point;
starting a first cell search step using the primary synchronization channel signal at a given time point, and storing the index count value at a time point where slot synchronization is acquired, as a slot timing index;
starting a second cell search step using the secondary synchronization channel signal at a time point of the slot timing index, and storing the index count value at a time point where frame synchronization and a codeword group are acquired, as a frame timing index;
and
performing a third cell search step using the common pilot channel at a given time point, and detecting a scrambling code used by the Node B among scrambling codes constituting the codeword group.

2 more elements

An apparatus for performing a cell search by receiving from a Node B a primary synchronization channel signal transmitted with as many chips as a predetermined chip length at a beginning of each slot, a secondary synchronization channel signal overlapping with the primary synchronization channel signal, being transmitted while maintaining orthogonality with the primary synchronization channel signal, and a common pilot channel signal scrambled by a unique scrambling code, a one-frame length of the common pilot channel signal being equal to a period of the scrambling code, each frame being comprised of a predetermined number M of slots each having a predetermined chip length N, in a UE (User Equipment) for a W-CDMA (Wideband Code Division Multiple Access) mobile communication system, the apparatus comprising:

a controller for generating an initialization command and a search command for each of first to third cell search steps;
an index counter for counting an index count value within a range of a one-frame length by a period equal to or shorter than the predetermined chip length after being initialized at a predetermined time point;
a first searcher for starting the first cell search step using the primary synchronization channel signal at a given time point in response to the initialization command and the search command from the controller, and storing the index count value at a time point where slot synchronization is acquired, as a slot timing index;
a second searcher for starting the second cell search step using the secondary synchronization channel signal at a time point where the slot timing index matches the index count value, in response to the initialization command and the search command from the controller, and storing the index count value at a time point where the frame synchronization and a codeword code are acquired, as a frame timing index;
and
a third searcher for performing the third cell search step using the common pilot channel signal at a given time point in response to the initialization command and the search command from the controller, and detecting a scrambling code used by the Node B among scrambling codes constituting the codeword group.

3 more elements

A method for performing a cell search by receiving from a Node B a primary synchronization channel signal transmitted with as many chips as a predetermined chip length at a beginning of each slot, a secondary synchronization channel signal overlapping with the primary synchronization channel signal, being transmitted while maintaining orthogonality with the primary synchronization channel signal, and a common pilot channel signal scrambled by a unique scrambling code, a one-frame length of the common pilot channel signal being equal to a period of the scrambling code, each frame being comprised of a predetermined number M of slots each having a predetermined chip length N, in a UE (User Equipment) for a W-CDMA (Wideband Code Division Multiple Access) mobile communication system, the method comprising the steps of:

after being initialized, upon power up of the UE, counting a slot count value within a one-frame length range between 0 and M−1 at periods of a slot, and counting a lower count value within a one-slot length range between 0 and K×N−1 at periods of a multiple K×N of the chip length N;
acquiring cell synchronization by performing a first cell search step by using the primary synchronization channel signal, and defining the lower count value at a time point where the cell synchronization is acquired, as a slot timing index;
acquiring a code group and frame synchronization by performing a second cell search step by using the secondary synchronization channel signal at a time point where the slot timing index matches the lower count value, and defining the slot count value and the lower count value at a time point where the code group and the frame synchronization are acquired, as a frame timing index;
performing a third cell search step by using the common pilot channel signal at a time point where the frame timing index matches the slot count value and the lower count value;
and
after the third cell search step, detecting a scrambling code used by the Node B based on the search result.

3 more elements

a controller for generating an initialization command and a search command for each of first to third cell search steps, and detecting a scrambling code used by the Node B based on the cell search result;
a slot counter, initialized upon power up of the UE, for counting a slot count value within a one-frame length range between 0 and M−1 at periods of a slot;
a lower count value, initialized upon power up of the UE, for counting a lower count value within a one-slot length range between 0 and K×N−1 at periods of a multiple K×N of the chip length N;
a first-step operation signal generator for generating a first-step search operation signal at a given time point in response to the search command from the controller;
a first-step searcher, initialized in response to the initialization command from the controller, for acquiring slot synchronization by performing the first cell search step using the primary synchronization channel signal in response to the first-step search operation signal from the first-step operation signal generator, reporting the search result to the controller, and storing the index count value at a time point where slot synchronization is acquired, as a slot timing index;
a second-step operation signal generator for generating a second-step search operation signal at a time point where the slot timing index matches the lower count value, in response to the search command from the controller;
a second-step searcher, initialized in response to the initialization command from the controller, for acquiring frame synchronization and a codeword group by performing the second cell search step using the secondary synchronization channel signal in response to the second-step search operation signal from the second-step operation signal generator, reporting the search result to the controller, and storing the slot count value and the lower count value at a time point where the frame synchronization and the codeword group are acquired, as a frame timing index
a third-step operation signal generator for generating a third-step search operation signal at a given time point where the frame timing index matches the slot count value and the lower count value, in response to the search command from the controller;
a third-step searcher, initialized in response to the initialization command from the controller, for performing the third cell search step using the common pilot channel signal in response to the third-step search operation signal from the third-step operation signal generator, detecting a scrambling code used by the Node B among scrambling codes constituting the codeword group, and reporting the search result to the controller;
and
a memory for storing a lower count value from the lower counter at a time point where a save command is received from the first-step searcher, as the slot timing index, and storing a slot count value from the slot counter and a lower count value from the lower counter at a time point where a save command is received from the second-step searcher, as the frame timing index.

8 more elements

Dependencies are inferred from the claim text.

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US 2003/0169702 A1Published application

Apparatus and method for generating reference timing in a CDMA mobile communication system

AssigneeSamsung Electronics Co., Ltd.

InventorsDong-Ryeol Ryu, Joo-Kwang Kim, Kwang-Man Ok, Chae-Man Lim, Seong-Ho Hur

Life of this patent

Estimating the term…

Abstract

Claims22

Dependent claims

counting an index count value within a range of a one-frame length by a period shorter than or equal to the predetermined chip length, after being initialized at a predetermined time point;
starting a first cell search step using the primary synchronization channel signal at a given time point, and storing the index count value at a time point where slot synchronization is acquired, as a slot timing index;
starting a second cell search step using the secondary synchronization channel signal at a time point of the slot timing index, and storing the index count value at a time point where frame synchronization and a codeword group are acquired, as a frame timing index;
and
performing a third cell search step using the common pilot channel at a given time point, and detecting a scrambling code used by the Node B among scrambling codes constituting the codeword group.

2 more elements

a controller for generating an initialization command and a search command for each of first to third cell search steps;
an index counter for counting an index count value within a range of a one-frame length by a period equal to or shorter than the predetermined chip length after being initialized at a predetermined time point;
a first searcher for starting the first cell search step using the primary synchronization channel signal at a given time point in response to the initialization command and the search command from the controller, and storing the index count value at a time point where slot synchronization is acquired, as a slot timing index;
a second searcher for starting the second cell search step using the secondary synchronization channel signal at a time point where the slot timing index matches the index count value, in response to the initialization command and the search command from the controller, and storing the index count value at a time point where the frame synchronization and a codeword code are acquired, as a frame timing index;
and
a third searcher for performing the third cell search step using the common pilot channel signal at a given time point in response to the initialization command and the search command from the controller, and detecting a scrambling code used by the Node B among scrambling codes constituting the codeword group.

3 more elements

A method for performing a cell search by receiving from a Node B a primary synchronization channel signal transmitted with as many chips as a predetermined chip length at a beginning of each slot, a secondary synchronization channel signal overlapping with the primary synchronization channel signal, being transmitted while maintaining orthogonality with the primary synchronization channel signal, and a common pilot channel signal scrambled by a unique scrambling code, a one-frame length of the common pilot channel signal being equal to a period of the scrambling code, each frame being comprised of a predetermined number M of slots each having a predetermined chip length N, in a UE (User Equipment) for a W-CDMA (Wideband Code Division Multiple Access) mobile communication system, the method comprising the steps of:

after being initialized, upon power up of the UE, counting a slot count value within a one-frame length range between 0 and M−1 at periods of a slot, and counting a lower count value within a one-slot length range between 0 and K×N−1 at periods of a multiple K×N of the chip length N;
acquiring cell synchronization by performing a first cell search step by using the primary synchronization channel signal, and defining the lower count value at a time point where the cell synchronization is acquired, as a slot timing index;
acquiring a code group and frame synchronization by performing a second cell search step by using the secondary synchronization channel signal at a time point where the slot timing index matches the lower count value, and defining the slot count value and the lower count value at a time point where the code group and the frame synchronization are acquired, as a frame timing index;
performing a third cell search step by using the common pilot channel signal at a time point where the frame timing index matches the slot count value and the lower count value;
and
after the third cell search step, detecting a scrambling code used by the Node B based on the search result.

3 more elements

a controller for generating an initialization command and a search command for each of first to third cell search steps, and detecting a scrambling code used by the Node B based on the cell search result;
a slot counter, initialized upon power up of the UE, for counting a slot count value within a one-frame length range between 0 and M−1 at periods of a slot;
a lower count value, initialized upon power up of the UE, for counting a lower count value within a one-slot length range between 0 and K×N−1 at periods of a multiple K×N of the chip length N;
a first-step operation signal generator for generating a first-step search operation signal at a given time point in response to the search command from the controller;
a first-step searcher, initialized in response to the initialization command from the controller, for acquiring slot synchronization by performing the first cell search step using the primary synchronization channel signal in response to the first-step search operation signal from the first-step operation signal generator, reporting the search result to the controller, and storing the index count value at a time point where slot synchronization is acquired, as a slot timing index;
a second-step operation signal generator for generating a second-step search operation signal at a time point where the slot timing index matches the lower count value, in response to the search command from the controller;
a second-step searcher, initialized in response to the initialization command from the controller, for acquiring frame synchronization and a codeword group by performing the second cell search step using the secondary synchronization channel signal in response to the second-step search operation signal from the second-step operation signal generator, reporting the search result to the controller, and storing the slot count value and the lower count value at a time point where the frame synchronization and the codeword group are acquired, as a frame timing index
a third-step operation signal generator for generating a third-step search operation signal at a given time point where the frame timing index matches the slot count value and the lower count value, in response to the search command from the controller;
a third-step searcher, initialized in response to the initialization command from the controller, for performing the third cell search step using the common pilot channel signal in response to the third-step search operation signal from the third-step operation signal generator, detecting a scrambling code used by the Node B among scrambling codes constituting the codeword group, and reporting the search result to the controller;
and
a memory for storing a lower count value from the lower counter at a time point where a save command is received from the first-step searcher, as the slot timing index, and storing a slot count value from the slot counter and a lower count value from the lower counter at a time point where a save command is received from the second-step searcher, as the frame timing index.

8 more elements

Dependencies are inferred from the claim text.