Spreading code generation apparatus and CDMA receiver
AssigneeMatsushita Electric Industries Co., Ltd.
InventorYuzo Eto
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Abstract
The spreading code generation apparatus of the present invention temporarily stores a spreading code string generated from one spreading code generator in memory (shift register or RAM). Then, after providing a necessary delay based on synchronization acquisition information output from a searcher, the code generation apparatus supplies the spreading code stored in memory to one of a plurality of correlators. This makes it possible to give a spreading code whose phase is adjusted to correspond to a specific path of multi-paths to the correlator.
Claims10
A spreading code generation apparatus comprising:
- one spreading code generator;
- a storage circuit capable of storing spreading codes generated from said one spreading code generator;
- a searcher that acquires synchronization of a CDMA signal received through multi-paths and outputs synchronization acquisition information including reference timing information necessary to specify a relative positional relationship between paths and delay time information on delays relative to the reference timing;
- a plurality of correlators provided according to said paths that despread said CDMA signal at timings corresponding to the respective paths of said multipaths;
- and
- a timing control circuit that controls the timing of supplying said spreading codes stored in said storage circuit to said plurality of correlators based on said synchronization acquisition information output from said searcher.
A spreading code generation apparatus comprising:
- one spreading code generator;
- a shift register that temporarily stores spreading codes generated from said one spreading code generator and outputs said spreading codes with different delays in parallel from respective taps;
- a searcher that acquires synchronization of a CDMA signal received through multi-paths and outputs synchronization acquisition information including reference timing information necessary to specify a relative positional relationship between paths and delay time information on delays relative to the reference timing;
- a plurality of correlators provided according to said paths that despread said CDMA signal at timings corresponding to the respective paths of said multipaths;
- and
- at least one selector provided between said shift register and said plurality of correlators that selects one of spreading codes with different delays output in parallel from the respective taps of said shift register based on said synchronization acquisition information output from said searcher and supplies the selected spreading code to one of said plurality of correlators.
A spreading code generation apparatus comprising:
- one spreading code generator;
- a RAM for storing spreading codes generated from said one spreading code generator;
- a searcher that acquires synchronization of a CDMA signal received through multi-paths and outputs synchronization acquisition information including reference timing information necessary to specify a relative positional relationship between paths and delay time information on delays relative to the reference timing;
- a plurality of correlators provided according to said paths that despread said CDMA signal at timings corresponding to the respective paths of said multipaths;
- a write access control circuit that continuously generates write addresses for said RAM in synchronization with a predetermined operating clock and writes data corresponding to 1 chip of spreading codes output from said one spreading code generator at a time at different addresses of said RAM;
- and
- a read access control circuit that continuously generates read addresses for said RAM in synchronization with a predetermined operating clock and controls the timing at which the addresses generated are supplied to said RAM based on said synchronization acquisition information output from said searcher.
A spreading code generating method of generating spreading codes whose phases are adjusted to correspond to respective paths of multi-paths, comprising the steps of:
- temporarily storing a spreading code string generated from one spreading code generator in a shift register configured to output data in parallel from respective taps;
- and
- selecting one of spreading codes with different delays output in parallel from memory based on reference timing information and synchronization acquisition information including information indicating time delays relative to the reference timing output from a searcher.
A spreading code generating method of generating spreading codes whose phases are adjusted to correspond to respective paths of multi-paths, comprising the steps of:
- storing a spreading code string generated from one spreading code generator in a RAM;
- and
- controlling the timing at which read addresses are supplied to said RAM based on synchronization acquisition information output from a searcher and thereby generating spreading codes with phases adjusted.
Dependencies are inferred from the claim text.