Multi-carrier CDMA transmitting device and method using block-based multi-carrier spreading
First Claim
1. A transfer device for a multi-carrier CDMA scheme, comprising:
- a serial to parallel converter for converting input data into parallel data;
a plurality of copiers for copying each of the parallel data as many times as the number of spread factors;
a spreader for spreading the respective data output by the plurality of copiers with respect to a frequency axis using different spread codes per user, when-multiplexing users using a block-based partial carrier spreading, the block being composed of multi carriers; and
an IFFT unit for performing inverse fast Fourier transform (IFFT) on the data spread by the spreader and transmitting the IFFT-performed data through a transmit antenna,wherein the spreader divides the spread codes which are multiplied to a plurality of data output by one of the copiers respectively into blocks corresponding to the number of the users, applies the different spread codes of the divided blocks correspond to the users and performs the block-based partial carrier spreading.
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Abstract
A multi-carrier CDMA transfer device using block-based partial-carrier spreading uses block-based partial-carrier spreading in the multi-cell environment to be applied to MC-CDMA models (FH-MC/CDMA TDD) that are strong against multi-path fading. A transmitter of the transfer device spreads carriers per block in the frequency domain by using the block-based partial-carrier spreading, and a receiver despreads received signals by using the block-based partial-carrier and restore original data. Optionally, an array antenna having a plurality of antenna elements is applied to the transmitter and the receiver, and weights are adaptively applied depending on the channel quality when transmitting and receiving signals through the antenna elements. Therefore, frequency diversity is obtainable and inter-cell interference and inter-code interference is optimized in the MC-CDMA method. Also, changes of frequency hopping reduce temporal variations of channels and prevent a high SN ratio.
40 Citations
31 Claims
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1. A transfer device for a multi-carrier CDMA scheme, comprising:
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a serial to parallel converter for converting input data into parallel data; a plurality of copiers for copying each of the parallel data as many times as the number of spread factors; a spreader for spreading the respective data output by the plurality of copiers with respect to a frequency axis using different spread codes per user, when-multiplexing users using a block-based partial carrier spreading, the block being composed of multi carriers; and an IFFT unit for performing inverse fast Fourier transform (IFFT) on the data spread by the spreader and transmitting the IFFT-performed data through a transmit antenna, wherein the spreader divides the spread codes which are multiplied to a plurality of data output by one of the copiers respectively into blocks corresponding to the number of the users, applies the different spread codes of the divided blocks correspond to the users and performs the block-based partial carrier spreading. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A transfer device for a multi-carrier CDMA, comprising:
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an array antenna having a plurality of antenna elements; a spreader for copying the data output by the array antenna as many times as a predetermined number of blocks, and spreading the copied data blocks with respect to a frequency axis using different spread codes per user, the spreader spreading a part of the copied data blocks using a block-based partial carrier spreading and multiplexing users, the block being composed of multi carriers; N adaptive transmission controllers for applying weights to the respective data spread by the spreader, performing inverse fast Fourier transform (IFFT) on the weighted data, and outputting the executed data to a corresponding antenna element of the antenna elements wherein N corresponds to the number of the antenna elements of the array antenna; and a weight controller for controlling the weights of the adaptive transmission controllers according to a channel quality, wherein the spreader divides the spread codes which are multiplied to a plurality of data output by one of the copiers respectively into blocks corresponding to the number of the users, applies the different spread codes of the divided blocks correspond to the users and performs the block-based partial carrier spreading. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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24. A transfer device comprising:
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an array antenna having a plurality of antenna elements; a transmitter for applying a weight to the respective transmission data and transmitting the weighted transmission data through the array antenna according to a multi-carrier CDMA method based on block-based partial-carrier spreading, the weight allowing adaptive control, the transmitter comprising a spreader for copying the transmission data as many times as a predetermined number of blocks, and spreading the copied data blocks with respect to a frequency axis using different spread codes per user, the spreader spreading the copied data blocks using a block-based partial carrier spreading and multiplexing users, the block being composed of multi carriers; and a receiver for receiving the data through the array antenna and respectively applying a weight to the received data according to the multi-carrier CDMA method based on the block-based partial-carrier spreading, the weight allowing adaptive control, wherein the receiver comprises a despreader for despreading the received data with different despread codes, the despread codes being differently applying per user and being identical to the spread codes, wherein the spreader divides the spread codes which are multiplied to a plurality of data output by one of the copiers respectively into blocks corresponding to the number of the users, applies the different spread codes of the divided blocks correspond to the users and performs the block-based partial carrier spreading. - View Dependent Claims (25, 26, 27, 28, 29)
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30. A transfer method for a multi-carrier CDMA, comprising:
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(a) converting input data into parallel data; (b) copying the converted parallel data as many times as a predetermined number of blocks, and spreading the copied data blocks with respect to a frequency axis using different spread codes per user, the spreading spreading the copied data blocks using a block-based partial carrier spreading and multiplexing users, the block being composed of multi carriers; and (c) performing inverse fast Fourier transform (IFFT) on the spread data and transmitting the executed data through a transmit antenna, Wherein in b), the spread codes which are multiplied to one of the copied data blocks respectively is divided into blocks corresponding to the number of the users and the different spread codes of the divided blocks are applied correspond to the users and the block-based partial carrier spreading is performed. - View Dependent Claims (31)
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Specification