CDMA transmission system
AssigneeU.S. Philips Corporation
InventorHerbert Panzer
Life of this patent
Estimating the term…
Abstract
A CDMA transmission system wherein a data sequence which is to be transmitted is frequency band spread by multiplying the data words therein by selected code words. In order to minimize the necessary bandwidth, a frame structure is established and the spread spectrum data words are compressed into data bursts each of which is included in one or more time slots of a data frame. Within a frame a data burst is located at a particular time delay t.sub.0 following commencement of the frame and has a duration t.sub.d corresponding to the bit rate of the data burst.
Claims6
A CDMA transmission system comprising a plurality of stations each having a transmitter and a receiver, each transmitter being for converting an original sequence of data words which have various bit rates into a sequence of spread spectrum data words by encoding the original data words in accordance with selected code words and transmitting the spread spectrum data words;
- each receiver being for receiving transmitted spread spectrum data words and decoding them in accordance with the selected code words by which they were encoded, so as to recover the original sequence of data words;
- characterized in that said transmitter comprises:
- frame generating means for compressing the data words in the original sequence into data bursts having higher bit rates and shorter durations, and including the data bursts in time slots of a sequence of data frames;
- frequency spreading means coupled to the frame generating means for spreading the frequency spectrum of the data bursts by encoding them in accordance with said selected code words, the frequency spectrum of a data burst being spread, as a function of the bit rate thereof;
- power control means coupled to said frequency spreading means for setting transmit power levels of the spread spectrum data bursts as a function of the bit rates thereof, higher transmit power levels being provided for data bursts which have higher bit rates;
- and
- transmission control means for controlling the compression provided by said frame generating means for each of said data words and the positioning of said data bursts in said frames, in order to substantially uniformly fill the bandwidth of each of said frames.
A transmitter for use in a CDMA transmission system wherein said transmitter is for converting an original sequence of data words which may have various bit rates into a sequence of spread spectrum data words by encoding the original data words in accordance with selected code words, and transmittiting the spread spectrum data words;
- characterized in that said transmitter comprises:
- frame generating means for compressing the data words in the original sequence into data bursts having higher bit rates and shorter durations, and including the data bursts in time slots of a sequence of data frames;
- frequency spreading means coupled to the frame generating means for spreading the frequency spectrum of the data bursts by encoding them in accordance with said selected code words, the frequency spectrum of a data burst being spread as a function of the bit rate thereof;
- power control means coupled to said frequency spreading means for setting transmit power levels of the spread spectrum data bursts as a function of the bit rates thereof, higher transmit power levels being provided for data bursts which have higher bit rates;
- and
- transmission control means for controlling the compression provided by said frame generating means for each of said data words and the positioning of said data bursts in said frames, in order to substantially uniformly fill the bandwidth of each of said frames.
Dependencies are inferred from the claim text.