Method and apparatus for generating complex four-phase sequences for a CDMA communication system
AssigneeInterDigital Technology Corporation
InventorFatih M. Ozluturk
Life of this patent
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Abstract
An improved sequence design for code-division multiple access (CDMA) communications generating complex four-phase pseudo-random code sequences which may be directly mapped to a quadrature phase shift keying (QPSK) signal constellation.
Claims25
A transmission apparatus for generating a complex four-phase pseudo-random sequence having I and Q portions used for spreading voice or data signals comprising:
- a shift register having a plurality of positions;
- an accumulator having a first input for receiving an output from said shift register and a second input for receiving a predetermined value, said accumulator combining data received via said first and second inputs and outputting the combined data to said shift register;
- whereby bits from a first predetermined position within said shift register are used to generate said I portion and bits from a second predetermined position within said shift register are used to generate said Q portion;
- and
- whereby said predetermined value is a quotient of a parameter M divided by a parameter N, wherein M and N are integers and wherein M is relatively prime to N.
A transmitter, including an apparatus for generating complex four-phase pseudo-random sequences for code division multiple access (CDMA) communication comprising:
- means for outputting a series of values;
- means for outputting an incremental value related to said series of values;
- a first mixing means having a first input for receiving said series of values, a second input for receiving said incremental value and a first output;
- and a second mixing means having a first input receiving the output of said first mixing means, a second input receiving a value M/N, a first output and a second output;
- whereby said first output of said second mixer generates said I code and said second output of said second mixer generates said Q code, said I and Q codes being used for said sequences.
A transmitter, including an apparatus for generating four-phase pseudo-random sequences used for spreading a voice or data signal for code division multiple access (CDMA) communication, said apparatus comprising:
- means for selecting a parameter M and a processing gain N wherein M and N are integers and M is relatively prime to N;
- means for dividing the parameter M by the processing gain N to provide a quotient;
- means for mixing the quotient with an arithmetic progression of values and an incremental value of said arithmetic progression of values to provide a result;
- means for extracting a first bit and a second bit from the result;
- means for generating I and Q data from the extracted first and second bits;
- and means for utilizing said I and Q data to spread said voice or data signals and generate said pseudo-random sequence for CDMA communication.
An apparatus in a code division multiple access (CDMA) transmitter for generating complex four-phase codes, comprising:
- a plurality of flip flops, which are initially set to zero;
- an accumulator having a first input for receiving an output from said plurality of flip flops and a second input for receiving a quotient of a parameter M divided by a parameter N, wherein M and N are integers and wherein M is relatively prime to N;
- said accumulator combining data received via said first and second inputs and outputting the combined data to said flip flops;
- an extractor extracting a first bit and a second bit from the flip flops;
- and means for converting the extracted first and second bits to generate I and Q codes respectively.
A transmitter which generates and transits pseudo-random codes, comprising:
- means for outputting an arithmetic progression of values;
- means for outputting an incremental value of said arithmetic progression of values;
- a first mixer having a first input for receiving said arithmetic progression of values and a second input for receiving said incremental value;
- a second mixer having a first input receiving an output of said first mixer and a second input receiving the quotient of a parameter M divided by a parameter N, wherein M and N are integers and wherein M is relatively prime to N;
- an extractor associated with the output of said second mixer for extracting a first bit and a second bit from the second mixer;
- and
- means for converting the extracted first and second bits to I and Q codes.
A code division multiple access (CDMA) transmitter, including an apparatus for generating complex four-phase pseudo-random spreading sequences comprising:
- a plurality of flip flops, which are initially set to zero, and which represent progressively more significant bits;
- an accumulator having a first input for receiving an output from said divided by a parameter N, wherein M and N are integers and wherein M is relatively prime to N;
- said accumulator combining data received via said first and second inputs and outputting the combined data to said flip flops;
- means for extracting a first bit and a second bit;
- and
- means for converting said extracted bits into I and Q codes, respectively.
A code division multiple access (CDMA) transmitter including a code generator for generating complex four-phase pseudo-random sequences, comprising:
- means for outputting an arithmetic progression of values;
- means for outputting an incremental value of said arithmetic progression of values;
- a first mixer having a first input for receiving said arithmetic progression of values and a second input for receiving said incremental value;
- a second mixer having a first input for receiving the output of said first mixer and a second input receiving the quotient of a parameter M divided by a parameter N, wherein M and N are integers and wherein M is relatively prime to N;
- and
- an extractor for extracting a first bit and a second bit from the output of the second mixer.
Dependencies are inferred from the claim text.