초록 ▼

A CDMA communications method capable of multiplex transmission of data over a wide range from a low rate to high rate such as image data without a considerable increase in a circuit scale. A fundamental transmission rate is determined, for example, at 32 kbps, a rate higher than 8 kbps conventionall

A CDMA communications method capable of multiplex transmission of data over a wide range from a low rate to high rate such as image data without a considerable increase in a circuit scale. A fundamental transmission rate is determined, for example, at 32 kbps, a rate higher than 8 kbps conventionally used. The data whose transmission rate is equal to the fundamental transmission rate is transmitted in frames including no vacant portion. Data whose transmission rate is lower than the fundamental transmission rate (16 kbps, for example) is transmitted in frames including vacant portions. The vacant portions are not transmitted. This makes it possible to receive data through other channels during a time period associated with the vacant portions. Data of a higher transmission rate, 128 kbps, for example, can be multiplexed and transmitted through four channels using different spreading codes.

대표청구항 ▼

A CDMA (Code Division Multiple Access) communications method for transmitting transmission data through one or more channels between base stations and mobile stations, said method comprising the steps of: generating a frame including at least a part of said transmission data and a vacant portion whe

A CDMA (Code Division Multiple Access) communications method for transmitting transmission data through one or more channels between base stations and mobile stations, said method comprising the steps of: generating a frame including at least a part of said transmission data and a vacant portion when a transmission rate of said transmission data is lower than a predetermined rate, said vacant portion having no data to be transmitted; performing a primary modulation of said frame to produce a primary modulation signal; performing a secondary modulation of said primary modulation signal using a spreading code, to produce a secondary modulated wideband signal, said spreading code being different for each of said channels; transmitting said wideband signal using a carrier, wherein said step of generating a frame comprises the step of time-compressing said transmission data by a factor of N at every time period T where N is an integer greater than one, and T is the length of a frame at said predetermined transmission rate when the transmission rate of said transmission data is 1/N of said predetermined transmission rate, thereby providing said frame with said vacant portion.