MULTI-VALUE QAM COMMUNICATION SYSTEM

• Main Author: SAITO YOICHI
• Format: Patent
• Language: English
• Published: 08.01.1990
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHICCOMMUNICATION

PURPOSE:To improve the coding efficiency and coding gain by dividing a base band signal into a coding bit and a non-coding bit, using the non-coding bit as a partial set, allocating it at a point where an inter-signal distance is maximized and sending the result and reproducing the signal at the demodulator side by the opposite operation to above. CONSTITUTION:The sender side forms 2 sets of subset signals subject to error correction coding through independent block coding of r-bit (2<=r<m) among m-bit base band signals of multi-value 2 (m is a positive integer). Then the non-coding signal in (m-r) bits not subject to error correction is used as a subset in the r-bit and modulated in a way that the inter-signal distance, of (m-r) bits is maximized in the signal space after modulation and the result is sent. The reception side reproduces the received signal in the opposite operation to that at the sender side. Thus, the bit number possible for error correction is increased by nearly a multiple of m/r and the coding gain of the r-bit series is improved.