A method and apparatus for electrically generating sets of binary spreading-code sequences for use in a multi-node communication network. Also, a method for assigning disjoint sets of binary spreading-code sequences to different nodes of such a network. Each set of binary spreading-code sequences consists of multiple sequences, which are generated using two binary shift registers. The sequences can be generated simultaneously, or sequence segments can be generated sequentially. To generate sequences simultaneously, the contents of multiple pairs of stages of two linear-feedback binary shift registers are combined by modulo-2 addition, where each pair of stages consists of one stage from each of the two binary shift registers. To generate sequence segments sequentially, the contents of a single stage of a first binary shift register are combined by modulo-2 addition with the contents of a single stage of a second binary shift register, where new fills are switched into each of the registers at the beginning of each period. To assign disjoint sets of binary spreading-code sequences to different nodes of the network, the initial fill of the first binary shift register is fixed and different initial fills are specified for the second binary shift register.
This is a divisional application of U.S. patent application Ser. No. 08/456,077 filed May 31, 1995, now U.S. Pat. No. 5,815,526 issued Sep. 29, 1998, which was filed as a divisional application of U.S. patent application Ser. No. 08/100,334 filed Jul. 30, 1993 (now U.S. Pat. No. 5,452,328), which application was filed as a continuation of U.S. patent application Ser. No. 07/917,873 filed Jul. 23, 1992, now abandoned, which application was a divisional application of U.S. patent application Ser. No. 07/766,372 filed Sep. 27, 1991 (now U.S. Pat. No. 5,210,770).
An n-bit binary value corresponding to an amount of phase shift d is assigned to an SREG, and a shift operation is performed. An n-bit vector value corresponding to a decimal value "1" is assigned to an LAT as an initial value. Thereafter, the input from an SW is sequentially stored. An MUL performs a square operation within a Galois field GF (2.sup.n) for the output of the LAT. A DBL performs a double operation within the Galois field GF (2.sup.n) for the output of the MUL. The SW selects either of the outputs of the MUL and the DBL according to the output value from the MSB side of the SREG. After the shift operation and the latch operation are performed a number of times n, the n-bit output of the LAT is output as respective phase shift coefficients b.sub.0 through b.sub.n-1.
A method for allocating signature sequence used to distinguish my own signal from the other user's signals in a code division multiple access system comprising the steps of obtaining and selecting a Park-Song sequence based upon a specific equations; allocating the selected Park-Song sequence as the signature sequence to the pertinent user; performing communications using the allocated signature sequence; and generating the signature sequence as the Park-Song sequence added to the beginning and ending `patches` of itself at both ends.
A transmission method in a communications system has an orthogonal vector and a quasi orthogonal masking function for obtaining a quasi orthogonal vector from the orthogonal vector. Message signals are transmitted according to the quasi orthogonal vector. The method includes receiving the quasi orthogonal masking function and permuting the quasi orthogonal masking function to provide a further quasi orthogonal masking function. The further quasi orthogonal masking function is applied to the orthogonal vector to provide a further quasi orthogonal vector. The further quasi orthogonal vector is applied to the message signal to provide an encoded message signal for transmitting the encoded message signal within the communications system.
Encoding bits includes receiving a bit set to encode. An encoding lookup table associates correlithm objects of a space with bit sets. The space refers to an N-dimensional space, a correlithm object refers to a point of the space. The correlithm object corresponding to the received bit set is identified. The received bit set is encoded as the identified correlithm object. The identified correlithm object is imposed to encode the received bit set and subsequently decoded with table lookup using the reverse process.
A training sequence for a radio communications system is provided. According to one aspect of the present invention, the invention includes a core sequence of symbols, a successive repetition of the core sequence, and a marker sequence having a sequence of symbols different from the core sequence.
