Spread code assigning method in code spread radio communication using a plurality of transmission/reception antennas and code spread radio communication system using the same
First Claim
1. A spread code assigning method, in a code spread radio communication system including a first radio transmission device provided with a transmitter for transmitting different first through Mth code spread transmission signals from each of M (M is an integer of 2 or more) transmission antennas, and a second radio transmission device provided with a receiver for receiving and demodulating the first through Mth code spread transmission signals through N (N is an integer of 1 or more) reception antennas, for assigning spread codes to each of the transmission antennas, comprising:
- calculating a correlation value of each of the propagation paths between the transmission antennas and the reception antennas;
assigning, to the ith (i is an integer of 1 or more and M or less) transmission antenna having a propagation path of a correlation value exceeding a predetermined threshold value, only spread codes orthogonal to the spread codes of the jth (j is an integer of 1 or more and M or less, i≠
j) transmission antenna corresponding to the correlation value; and
assigning, to a transmission antenna having no propagation path of a correlation value exceeding the threshold value, spread codes without considering orthogonality to spread codes in the other transmission antennas.
1 Assignment
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Accused Products
Abstract
A receiver 102 connected to a plurality of reception antennas 121 and 122 includes a propagation path correlation estimation circuit 108. The propagation path correlation estimation circuit calculates a correlation value of each propagation path between each of transmission antennas 111 and 112 and each of the reception antennas and transmits the calculation result as propagation path correlation information (SCOR). A transmitter 101 connected to a plurality of transmission antennas includes a spread code assigning circuit 106. According to the propagation path correlation information, the spread code assigning circuit assigns only spread codes orthogonal to each other for the transmission antenna corresponding to a correlation value exceeding a threshold value and, for a transmission antenna having no propagation path of a correlation value exceeding the threshold value, assigns a spread code without considering orthogonality to a spread code in the other transmission antenna.
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Citations
17 Claims
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1. A spread code assigning method, in a code spread radio communication system including a first radio transmission device provided with a transmitter for transmitting different first through Mth code spread transmission signals from each of M (M is an integer of 2 or more) transmission antennas, and a second radio transmission device provided with a receiver for receiving and demodulating the first through Mth code spread transmission signals through N (N is an integer of 1 or more) reception antennas, for assigning spread codes to each of the transmission antennas, comprising:
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calculating a correlation value of each of the propagation paths between the transmission antennas and the reception antennas;
assigning, to the ith (i is an integer of 1 or more and M or less) transmission antenna having a propagation path of a correlation value exceeding a predetermined threshold value, only spread codes orthogonal to the spread codes of the jth (j is an integer of 1 or more and M or less, i≠
j) transmission antenna corresponding to the correlation value; and
assigning, to a transmission antenna having no propagation path of a correlation value exceeding the threshold value, spread codes without considering orthogonality to spread codes in the other transmission antennas. - View Dependent Claims (5, 7, 9)
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2. A spread code assigning method, in a code spread radio communication system including a first radio transmission device provided with a transmitter for transmitting different first through Mth code spread transmission signals from each of M (M is an integer of 2 or more) transmission antennas, and a second radio transmission device provided with a receiver for receiving and demodulating the first through Mth code spread transmission signals through N (N is an integer of 1 or more) reception antennas, for assigning spread codes to each of the transmission antennas, comprising:
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calculating a correlation value of each of the propagation paths between the transmission antennas and the reception antennas;
preferentially assigning, to the ith (i is an integer of 1 or more and M or less) transmission antenna having a propagation path of a correlation value exceeding a predetermined threshold value, spread codes having a small cross correlation value to spread codes of the jth (j is an integer of 1 or more and M or less, i≠
j) transmission antenna corresponding to the correlation value, andassigning, to a transmission antenna having no propagation path of a correlation value exceeding the threshold value, spread codes without considering orthogonality to spread codes in the other transmission antennas. - View Dependent Claims (3, 4, 6, 8)
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10. A spread code assigning method, in a code spread radio communication system including a first radio transmission device provided with a transmitter for transmitting different first through Mth code spread transmission signals from each of M (M is an integer of 2 or more) transmission antennas, and a second radio transmission device provided with a receiver for receiving and demodulating the first through Mth code spread transmission signals through N (N is an integer of 1 or more) reception antennas, for assigning spread codes to each of the transmission antennas comprising:
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detecting a reception quality at a time when each of said code spread transmission signals is received;
reducing, in the case that the detected reception quality is below an object minimum value, a maximum value of number of the spread codes assigned to the transmission antenna corresponding to the reception quality, and increasing, in the case that the detected reception quality exceeds an object maximum value, the maximum value of the number of spread codes assigned to the transmission antenna corresponding to the reception quality. - View Dependent Claims (11, 12)
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13. A code spread radio communication system including a first radio transmission device provided with a transmitter for transmitting different first through Mth code spread transmission signals from each of M (M is an integer of 2 or more) transmission antennas, and a second radio transmission device provided with a receiver for receiving and demodulating the first through Mth code spread transmission signals through N (N is an integer of 1 or more) reception antennas,
wherein the receiver is provided with a correlation value estimation unit for calculating a correlation value of each propagation path between each of the transmission antennas and each of the reception antennas and transmitting the calculated result as propagation path correlation information, wherein the transmitter is provided with a spread code assigning unit, and wherein the spread code assigning unit, based on the propagation path correlation information, assigns, to the ith (i is an integer of 1 or more and M or less) transmission antenna having a propagation path of a correlation value exceeding a predetermined threshold value, only spread codes orthogonal to the spread codes of the jth (j is an integer of 1 or more and M or less, i≠ - j) transmission antenna corresponding to the correlation value, and assigns, to a transmission antenna having no propagation path of a correlation value exceeding the threshold value, spread codes without considering orthogonality to spread codes in the other transmission antennas.
- View Dependent Claims (14, 15)
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16. A code spread radio communication system including a first radio transmission device provided with a transmitter for transmitting different first through Mth code spread transmission signals from each of M (M is an integer of 2 or more) transmission antennas, and a second radio transmission device provided with a receiver for receiving and demodulating the first through Mth code spread transmission signals with N (N is an integer of 1 or more) reception antennas, wherein
the receiver is provided with a reception quality detection unit for detecting reception quality at a time when each of the code spread transmission signals is received and a code multiplex number control signal generating unit, the code multiplex number control signal generating unit, in the case that the reception quality is below an object minimum value, transmitting the code multiplex number control information indicating decreasing of the maximum value of the number of spread codes assigned to the transmission antenna corresponding to the concerned reception quality, and also, in the case that the reception quality exceeds an object maximum value, transmitting the code multiplex number control information indicating increasing of the maximum value of the number of spread codes assigned to the transmission antenna corresponding to the concerned reception quality, and wherein the transmitter is provided with a spread code assigning unit for assigning spread codes to each of the transmission antenna based on the code multiplex number control information.
Specification