Multiple users share ONE channel. CRT separates them algebraically. CC0. No patents.
Traditional CDMA: each user gets a Walsh-Hadamard spreading code (NxN matrix). CRT CDMA: the ring Z/970200Z = Z/8 x Z/9 x Z/25 x Z/49 x Z/11 IS the code. ENCODING (transmit): 1. Each user i has a unique spreading key k_i in Z/970200Z 2. User's data symbol d (0-255 byte) is spread: s_i = d * k_i mod N 3. CRT decomposes s_i into 5 channels: (s mod 8, s mod 9, ..., s mod 11) 4. All users' channel signals are SUMMED on the shared medium DECODING (receive): 1. Receiver knows user i's key k_i 2. Compute k_i^(-1) mod N (modular inverse exists when gcd(k_i, N) = 1) 3. Multiply received composite: d_i = S * k_i^(-1) mod N 4. The CRT structure ensures algebraic separation — no interference WHY CRT WINS: - Walsh-Hadamard: O(N^2) matrix operations, fixed code length - CRT: O(1) encode/decode via modular arithmetic, 970200 possible codes - 5 independent channels = 5 independent noise dimensions - L=11 channel = FREE error detection on every transmission - No code assignment authority needed — the algebra IS the protocol
Users:
All users' signals combined on the shared medium:
Noise level: 0%