DE-MAPPING METHOD FOR WIRELESS COMMUNICATIONS SYSTEMS

• US 20050111563A1
• Filed: 12/22/2003
• Published: 05/26/2005
• Est. Priority Date: 11/20/2003
• Status: Abandoned Application

• Current Assignee: SYNCOMM Technology Corp.
• Original Assignee: SYNCOMM Technology Corp.
• Inventors: Tseng, Hsu-Hsiang
• Application Number:
  US10/707,586
• Publication Number:
  US 20050111563A1
• Time in Patent Office: Days
• US Class Current: 375/261
• CPC Class Codes: H04L 27/2273 associated with quadrature demodulation, e.g. Costas loop
• CPC Class Codes: H04L 27/2647 Arrangements specific to the receiver only equalisation H04L27/01
• CPC Class Codes: H04L 27/34 Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems

Abstract

A de-mapping method for wireless communications systems transforms an I signal and a Q signal transformed from wireless signals received by a receiver in a wireless communications system into a plurality of sequentially ordered I and Q weighting values respectively. The first I and the first Q weighting values are set to be values of the I and Q signals respectively, and following I and Q weighting values are set to be products of bit signs corresponding to preceding respective I and Q weighting values and differences between the preceding I and Q weighting values and a threshold value corresponding to the preceding I and Q weighting values by determining signs of the preceding I and Q weighting values.

Claims

1. A de-mapping method for a wireless communications system, the communications system comprising a transmitter and a receiver, the transmitter comprising an encoder, a mapping device, a signal modulator and a transmitting module, the receiver comprising a receiving module, a signal demodulator, a de-mapping device and a decoder, and the method comprising the following steps:

(a)encoding at least a bit string with the encoder;

(b)mapping the encoded bit string into a first gray-code-typed I signal and a first gray-code-typed Q signal with the mapping device;

(c)transforming the first gray-code-typed I and Q signals into a first modulated signal with the signal modulator;

(d)transforming the first modulated signal into an RF signal and transmitting the RF signal with the transmitting module;

(e)receiving the RF signal with the receiving module;

(f)transforming the RF signal into a second modulated signal and demodulating the second modulated signal into I signal and a second Q signal with the signal de-modulator;

(g)setting an initial I weighting value to be equal to (the second I signal)*(a first bit sign a first threshold value) with the de-mapping device;

(h)setting a following I weighting value to be a product of a bit sign corresponding to an I weighting value preceding the following I weighting value and a difference between the preceding I weighting value and a threshold value corresponding to the preceding I weighting value according to a sign of the preceding I weighting value with the de-mapping device;

(i)setting an initial Q weighting value to be equal to (the second Q signal)*(a second bit sign a second threshold value) with the de-mapping device;

(j)setting a following Q weighting value to be a product of a bit sign corresponding to a Q weighting value preceding the following Q weighting value and a difference between the preceding Q weighting value and a threshold value corresponding to the preceding Q weighting value according to a sign of the preceding Q weighting value with the de-mapping device; and

(k)quantizing all of the I and Q weighting values and transferring all of the quantized I and Q weighting values to the decoder.

2. The method of claim 1, wherein the first bit sign in step (g) is equal to 1 and the first threshold value is equal to zero.

3. The method of claim 1, wherein the de-mapping device in step (h) determines signs of all I weighting values preceding the following I weighting value and sets the following I weighting value thereafter.

4. The method of claim 1, wherein the second bit sign in step (i) is equal to 1 and the second threshold value is equal to zero.

5. The method of claim 1, wherein the de-mapping device in step (j) determines signs of all Q weighting values preceding the following Q weighting value and sets the following Q weighting value thereafter.