Radio access scheme in CDMA-based communication system
AssigneeNokia Corporation
InventorsKari Pajukoski, Esa Tiirola, Olav Tirkkonen
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Abstract
A solution for radio access in a code division multiple access (CDMA)-based telecommunication system, in which orthogonal spreading codes are used for separating data of a plurality of user entities, is provided. According to the solution, a different pilot symbol sequence is allocated to each user entity, and the pilot symbol sequences of user entities are selected by allocating different frequencies for pilot symbol sequences of different user entities according to a frequency division multiple access (FDMA) technique in order to mitigate the effect of multiple access interference.
Claims28
A method for radio access in a code division multiple access (CDMA)-based telecommunication system in which orthogonal spreading codes are used for separating data of a plurality of user entities, the method comprising:
- allocating to each user entity a different pilot symbol sequence;
- and
- selecting a pilot symbol sequence of a user entity by allocating a different frequency to each pilot symbol sequence of each user entity, the allocation being a frequency division multiple access (FDMA) technique to mitigate multiple access interference.
A radio network element in a code division multiple access (CDMA)-based telecommunication system in which orthogonal spreading codes are used for separating data of a plurality of user entities, the radio network element comprising:
- a communication interface to provide a communication connection with the plurality of user entities;
- and
- a control unit configured to allocate to each user entity a different pilot symbol sequence;
- and
- select each pilot symbol sequence of each user entity by allocating a different frequency to each pilot symbol sequence of each user entity, the allocation being a frequency division multiple access (FDMA) technique to mitigate multiple access interference.
A transceiver unit in a code division multiple access (CDMA) based telecommunication system in which orthogonal spreading codes are used for separating data of a plurality of user entities, the transceiver unit comprising:
- a communication interface to provide a connection to a radio network element;
- a control unit connected to the communication interface and being configured to:
- receive from the radio network element a pilot symbol sequence to be used in communication with another transceiver unit, the pilot symbol sequence being selected by allocating to the pilot symbol sequence a different frequency from other pilot symbol sequences of other user entities, the allocation being a frequency division multiple access (FDMA) technique to mitigate multiple access interference,
- transmit data and the pilot symbol sequence in frames such that each frame comprises at least one time interval for transmission of the pilot symbol sequence and a plurality of time intervals for transmission of data,
- spread a data symbol with an orthogonal spreading code to obtain a plurality of chip symbols for the data symbol,
- map the chip symbols into a plurality of time intervals for transmission to improve cross-correlation properties of the spreading code, and
- transmit the chip symbols in the plurality of time intervals.
A code division multiple access (CDMA)-based telecommunication system in which orthogonal spreading codes are used for separating data of a plurality of user entities, the telecommunication system comprising:
- a network element comprising a communication interface and a control unit connected to the communication interface;
- and
- one or more transceiver units, each transceiver unit comprising a communication interface to provide a connection between each transceiver unit and the network element,
- wherein the control unit of the network element is configured to
- allocate to each transceiver unit a different pilot symbol sequence,
- receive from the radio network element a pilot symbol sequence to be used in communication with another transceiver unit,
- select for each transceiver unit the different pilot symbol sequence by allocating a different frequency to each pilot symbol sequence of each different user entity, the allocation being a frequency division multiple access (FDMA) technique to mitigate multiple access interference,
- wherein each transceiver unit comprises a control unit being configured to transmit the data and the pilot symbol sequence in frames such that each frame comprises at least one time interval for transmission of the pilot symbol sequence and a plurality of time intervals for the transmission of the data,
- spread a data symbol with an orthogonal spreading code to obtain a plurality of chip symbols for the data symbol,
- map the chip symbols into a plurality of time intervals for transmission to improve cross-correlation properties of the spreading code, and
- transmit the chip symbols in the plurality of time intervals.
A radio network element in a code division multiple access (CDMA)-based telecommunication system in which orthogonal spreading codes are used for separating data of a plurality of user entities, the radio network element comprising:
- communication means for providing a communication connection with the plurality of user entities;
- means for allocating to each user entity a different pilot symbol sequence;
- means for selecting the pilot symbol sequence of a user entity by allocating a different frequency to each pilot symbol sequences of different user entities, the allocation being a frequency division multiple access (FDMA) technique to mitigate multiple access interference.
A computer program product encoding a computer program of instructions for executing a computer process for radio access in a code division multiple access (CDMA)-based telecommunication system in which orthogonal spreading codes are used for separating data of a plurality of user entities, the process comprising:
- allocating to each user entity a different pilot symbol sequence;
- and
- selecting the pilot symbol sequence of a user entity by allocating a different frequency to each pilot symbol sequences of different user entities, the allocation being a frequency division multiple access (FDMA) technique to mitigate multiple access interference.
A computer program distribution medium readable by a computer and encoding a computer program of instructions for executing a computer process for radio access in a code division multiple access (CDMA)-based telecommunication system in which orthogonal spreading codes are used for separating data of a plurality of user entities, the process comprising:
- allocating to each user entity a different pilot symbol sequence;
- and
- selecting the pilot symbol sequence of a user entity by allocating a different frequency to each pilot symbol sequences of different user entities, the allocation being a frequency division multiple access (FDMA) technique to mitigate multiple access interference.
Dependencies are inferred from the claim text.