CDMA communication method and spread spectrum communication system
First Claim
1. A code division multiple access communication method of dividing a frequency band in a communication channel between a base station and a plurality of mobile stations belonging to said base station into a reverse-link frequency band for transmitting a packet heading from each of said plurality of mobile stations to said base station and a forward-link frequency band for transmitting a packet heading from said base station to each of said plurality of mobile stations, said base station, in response to a reservation packet coming from each of said plurality of mobile stations, transmitting a response packet to each of said plurality of mobile stations for specifying a data traffic channel and a time slot, each of said plurality of mobile stations transmitting a data packet in said time slot specified on said data traffic channel specified in said response packet, said code division multiple access communication method comprising the steps of:
- defining, in each of the reverse link and the forward link frequency band, a plurality of carrier frequencies in correspondence to a plurality of sub frequency bands each having one of bandwidths of a plurality of types, said plurality of sub frequency bands being superimposed on each other in the reverse-link and the forward-link frequency band, and assigning in advance, for each of said plurality of mobile stations, a reverse-link sub frequency band and a forward-link sub frequency band from said plurality of sub frequency bands each of the reverse-link and the forward-link sub frequency band having a bandwidth matching data traffic rate;
spectrum-spreading, by each of said plurality of mobile stations, the reservation packet containing a mobile station identification by a spreading code for a reservation channel and transmitting a resultant packet by the prescribed carrier frequency corresponding to the reverse-link sub frequency band;
spectrum-spreading, by said base station, the response packet addressed to each of said plurality of mobile stations by a spreading code for a response channel and transmitting a resultant packet by the prescribed carrier frequency corresponding to the forward-link sub frequency band assigned to each of said plurality of mobile stations; and
spectrum-spreading, by each of said plurality of mobile stations, the data packet by a spreading code for the data traffic channel specified in said response packet and transmitting a resultant packet by the prescribed reverse-link carrier frequency.
1 Assignment
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Accused Products
Abstract
A frequency band for communication between a base station and mobile stations is divided into a reverse-link and a forward-link bands. In each of these bands, carrier frequencies are defined in correspondence with sub frequency bands each having one of several bandwidths. To each of these bands of each mobile station, a sub frequency band with a bandwidth matching a data traffic rate is assigned in advance. Each mobile station spectrum-spreads a reservation packet and transmits the resultant packet by a prescribed carrier frequency corresponding to the reverse-link sub frequency band. The base station spectrum-spreads a response packet and transmits the resultant packet by a prescribed carrier frequency corresponding to the forward-link sub frequency band. Each mobile station spectrum-spreads a data packet by a spreading code for data traffic channel specified in the response packet and transmits the resultant packet by the reverse-link carrier frequency.
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Citations
9 Claims
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1. A code division multiple access communication method of dividing a frequency band in a communication channel between a base station and a plurality of mobile stations belonging to said base station into a reverse-link frequency band for transmitting a packet heading from each of said plurality of mobile stations to said base station and a forward-link frequency band for transmitting a packet heading from said base station to each of said plurality of mobile stations, said base station, in response to a reservation packet coming from each of said plurality of mobile stations, transmitting a response packet to each of said plurality of mobile stations for specifying a data traffic channel and a time slot, each of said plurality of mobile stations transmitting a data packet in said time slot specified on said data traffic channel specified in said response packet, said code division multiple access communication method comprising the steps of:
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defining, in each of the reverse link and the forward link frequency band, a plurality of carrier frequencies in correspondence to a plurality of sub frequency bands each having one of bandwidths of a plurality of types, said plurality of sub frequency bands being superimposed on each other in the reverse-link and the forward-link frequency band, and assigning in advance, for each of said plurality of mobile stations, a reverse-link sub frequency band and a forward-link sub frequency band from said plurality of sub frequency bands each of the reverse-link and the forward-link sub frequency band having a bandwidth matching data traffic rate; spectrum-spreading, by each of said plurality of mobile stations, the reservation packet containing a mobile station identification by a spreading code for a reservation channel and transmitting a resultant packet by the prescribed carrier frequency corresponding to the reverse-link sub frequency band; spectrum-spreading, by said base station, the response packet addressed to each of said plurality of mobile stations by a spreading code for a response channel and transmitting a resultant packet by the prescribed carrier frequency corresponding to the forward-link sub frequency band assigned to each of said plurality of mobile stations; and spectrum-spreading, by each of said plurality of mobile stations, the data packet by a spreading code for the data traffic channel specified in said response packet and transmitting a resultant packet by the prescribed reverse-link carrier frequency. - View Dependent Claims (2, 3, 4)
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5. A spread spectrum communication system composed of a base station and a plurality of mobile stations belonging to said base station, said base station receiving a spectrum-spread reservation packet from each of said plurality of mobile stations and transmitting a spectrum-spread response packet for specifying a data traffic channel and a time slot to each of said plurality of mobile stations, each of said plurality of mobile stations transmitting a spectrum-spread data packet in a timing of the time slot specified on the data traffic channel specified in the response packet,
a communication channel between said base station and each of said plurality of mobile stations having a forward-link frequency band for transmitting a packet heading from said base station to each of said plurality of mobile stations and a reverse-link frequency band for transmitting a packet heading from each of said plurality of mobile stations to said base station, said base station comprising: -
a plurality of first receiving means each operating by one of a plurality of carrier frequencies predefined in the reverse-link frequency band; a plurality of first demodulating means, provided for each of said plurality of first receiving means, each for demodulating the spectrum-spread reservation packet and the spectrum-spread data packet by despreading an output signal outputted from each of said plurality of first receiving means; a plurality of first transmitting means each operating by one of a plurality of carrier frequencies predefined in the forward-link frequency band; and a plurality of first modulating means, provided for each of said plurality of transmitting means, each for spectrum-spreading a response packet and a data packet to output resultant packets to each of said plurality of first transmitting means; each of said plurality of mobile stations being assigned a reverse-link and a forward-link sub frequency band from a plurality of sub frequency bands related to said each of the carrier frequencies, each of the reverse-link and the forward-link sub frequency band having a bandwidth matching a data traffic rate of each of said plurality of mobile stations, said plurality of sub frequency bands being superimposed on each other in the reverse-link and the forward-link frequency band, each of said plurality of mobile stations comprising; second receiving means operating by the carrier frequency corresponding to the forward-link sub frequency band; second demodulating means for demodulating the spectrum-spread response packet and the spectrum-spread data packet from the base station by despreading an output signal outputted from said second receiving means; second transmitting means operating by the carrier frequency corresponding to the reverse-link sub frequency band; and second modulating means for spectrum-spreading a reservation packet and a data packet to output resultant packets to said second transmitting means. - View Dependent Claims (6, 7)
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8. A mobile station constituting by a plurality of said mobile stations a spread spectrum communication system along with a base station, said mobile station transmitting a spectrum-spread reservation packet to said base station by use of a reverse-link frequency band, receiving a spectrum-spread response packet for specifying a data traffic channel and a time slot from said base station by use of a forward-link frequency band, and transmitting a spectrum-spread data packet in a timing of the time slot specified on the data traffic channel specified in the spectrum-spread response packet to said base station by use of the reverse-link frequency band,
said mobile station being assigned a reverse-link and a forward-link sub frequency band from a plurality of sub frequency bands related to each of carrier frequencies, each of the reverse-link and forward-link sub frequency band having a bandwidth matching a data traffic rate of each of said plurality of mobile stations, said plurality of sub frequency bands being superimposed on each other in the reverse-link and the forward-link frequency band, said mobile station comprising: -
receiving means operating by the carrier frequency corresponding to the forward-link sub frequency band; demodulating means for demodulating the spectrum-spread response packet and a spectrum-spread data packet from said base station by despreading on output signal outputted from said receiving means; transmitting means operating by the carrier frequency corresponding to the reverse-link sub frequency band; and modulating means for spectrum-spreading a reservation packet and a data packet to output resultant packets to said transmitting means. - View Dependent Claims (9)
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Specification