1. A method for generating preamble sequences in a CDMA system, the method comprising the steps of:
- forming an outer code in a mobile station, wherein the outer code is formed from a generator from the group consisting of a maximum length sequence generator, a Kasami sequence generator, and a Gold sequence generator;
- forming an inner code in the mobile station; and multiplying the outer code by the inner code to generate a preamble sequence.
2. A method for generating preamble sequences in a CDMA system in accordance with claim 1, wherein the period of the outer code comprises k symbols, wherein k is a positive integer.
3. A method for generating preamble sequences in a CDMA system in accordance with claim 1, wherein the inner codes are formed as a series of M orthogonal code words having a length P, wherein M and P are positive integers.
4. A method for generating preamble sequences in a CDMA system in accordance with claim 1, wherein the inner codes comprise a set of Hadamard code words.
5. A method for generating preamble sequences in a CDMA system, the method comprising the steps of:
- forming an outer code in a mobile station;
- forming an inner code in the mobile station utilizing the following equation: ##EQU5##
- where s.sub.j, j=0,1, . . . ,M-1 are a set of orthogonal codewords of length P, where M and P are positive integers; and
- multiplying the outer code by the inner code to generate a preamble sequence.
6. A method for generating preamble sequences in a CDMA system, the method comprising the steps of:
- forming an outer code in a mobile station, the outer code comprising a 3840 symbol segment of an m-sequence of length 33554431;
- forming an inner code in the mobile station, the inner code being of the form: ##EQU6##
- where w.sub.j, j=0,1, . . . ,M-1 are a set of Hadamard codewords of length 16, M=256, and P=16.
7. A method for estimating the difference between the carrier frequency of the received signal and the receiver oscillator frequencies comprising:
- multiplying a received preamble by an outer code;
- correlating the resulting signal with the series of M orthogonal signals;
- multiplying consecutive symbols with the first symbol of each pair being complex conjugated;
- averaging (M-1) results;
- calculating the phase of the resulting complex number;
- multiplying the phase by the symbol period; and
- dividing by (2.pi.) to get the difference between the carrier frequency of the received signal and the receiver oscillator frequency.
8. A method for generating preamble sequences in a CDMA system, the method comprising the steps of:
- forming an outer code in a mobile station, the outer code comprising a 3840 symbol segment of a Gold-sequence of length 33554431;
- forming an inner code in the mobile station, the inner code being of the form: ##EQU7##
- where w.sub.j, j=0,1, . . . ,M-1 are a set of Hadamard codewords of length 16, M=256, and P=16.
