초록 ▼

In a radio communication system operating according to spread-spectrum techniques, data sequences of a number of communication channels are respectively spread with different orthogonal code sequences and are subsequently multiplied by a pseudo-random noise sequence. The parallel bit streams produce

In a radio communication system operating according to spread-spectrum techniques, data sequences of a number of communication channels are respectively spread with different orthogonal code sequences and are subsequently multiplied by a pseudo-random noise sequence. The parallel bit streams produced by this multiplication are supplied to a mapping memory in which an allocation rule--defined by the type of modulation being employed--is stored. This mapping memory produces respectively allocated I and Q values into the mapping memory from the bits read synchronously. These I and Q values are read from the mapping memory and are filtered in respective FIR filters and are then supplied to a quadrature modulator as baseband signals. Since the mapping memory emits only two sets of values (the I values and the Q values), only two FIR filters are needed.

대표청구항 ▼

[ I claim as my invention:] [1.] A radio communication system comprising:a plurality of communication channels;means for employing a spread-spectrum technique for spreading data sequences among said communication channels with different orthogonal code sequences, to obtain spread sequences;means for

[ I claim as my invention:] [1.] A radio communication system comprising:a plurality of communication channels;means for employing a spread-spectrum technique for spreading data sequences among said communication channels with different orthogonal code sequences, to obtain spread sequences;means for multiplying the data sequence in each communication channel by a pseudo-random noise sequence and thereby obtaining a plurality of I value bit streams and a plurality of Q value bit streams;a mapping memory having a plurality of inputs, to which said plurality of I value bit streams and said plurality of Q value bit streams are respectively supplied in parallel, and having first and second outputs, and comprising means for storing an allocation rule, defined by a type of modulation employed in said communication channels, for respectively allocating said inputs to said first and second outputs, for producing a single I value bit stream at said first output and a single Q value bit stream at said second output;a first FIR filter, supplied with said single I value bit stream, for producing a first FIR filter output;a second FIR filter, supplied with said single Q value bit stream, for producing a second FIR filter output; anda quadrature modulator supplied with said first and second FIR filter outputs as base band signals.