Method and apparatus for a demodulator circuit
OwnerMatthew James Collins, Jonathan Parkerinventors
Life of this patent
Estimating the term…
Abstract
A method and apparatus for a demodulator circuit in a communication system is described. The invention relates to a demodulator circuit in a communication system using a multi-carrier modulation scheme. The demodulator makes efficient use of channel state information for respective carriers in the multi-carrier modulation to de-map the received data. An efficient method of calculating channel state information is also disclosed.
Claims36
A demodulator circuit, wherein the demodulator circuit receives and demodulates a multi-carrier modulated (MCM) signal, and wherein the MCM signal comprises a plurality of carriers, comprising:
- (a) a de-mapping device, adapted to receive the MCM signal, wherein the de-mapping device generates decision data, comprising:
- (1) a channel state information (CSI) calculation device adapted to receive the MCM signal, wherein the CSI calculation device determines CSI for each carrier of the plurality of carriers and outputs an information signal comprising information regarding CSI for each carrier;
- and
- (2) a de-mapper adapted to receive the MCM signal and the information signal, operatively connected to the CSI calculation device, wherein the de-mapper uses the information signal to de-map the MCM signal, and wherein the de-mapper generates and outputs a decision data signal comprising decision data, and wherein the decision data can be based on the information signal, and wherein the decision data can be based on the MCM signal;
- and
- (b) a decoder, operatively connected to the de-mapping device, wherein the decoder decodes the decision data signal.
A method of demodulating a multi-carrier modulated (MCM) received signal, the method comprising the acts of:
- (a) calculating channel state information (CSI) for each carrier used in the MCM received signal;
- (b) de-mapping the MCM received signal based on the CSI calculated in act (a);
- (c) generating decision data based on the CSI calculated in act (a);
- and
- (d) decoding the decision data.
A method of demodulating a multi-carrier modulated (MCM) received signal, the method comprising the acts of:
- (a) receiving a MCM received signal;
- (b) calculating channel state information (CSI) for each carrier used in the MCM received signal;
- (c) de-mapping the MCM received signal to a received constellation point;
- (d) determining whether the CSI is less than a first threshold;
- (e) calculating decision data comprising an estimate of a pre-decoded bit and soft decision data based on a displacement between the received constellation point and an expected constellation point and returning to act (a) if the CSI is less than the first threshold;
- (f) determining whether the CSI is less than a second threshold, wherein the second threshold is greater than the first threshold;
- (g) calculating decision data comprising an estimate of a pre-decoded bit and soft decision data based on a position within a Gray coding and returning to act (a) if the CSI is less than the second threshold;
- (h) determining whether the CSI is less than a third threshold, wherein the third threshold is greater than the second threshold;
- (i) calculating decision data comprising an estimate of a pre-decoded bit and soft decision data indicating a low confidence level if the CSI is less than the third threshold;
- (j) puncturing all bits associated with the MCM received signal if the CSI is greater than or equal to the third threshold;
- and
- (k) returning to act (a).
An apparatus for demodulating a multi-carrier modulated (MCM) received signal, the apparatus comprising:
- (a) means for calculating channel state information (CSI) for each carrier used in the MCM received signal;
- (b) means, operatively connected to the calculating CSI means, for de-mapping the MCM received signal based on the CSI calculated in act (a) and generating decision data based on the CSI calculated in act (a);
- and
- (c) means, operatively connected to the de-mapping means, for decoding the decision data.
A computer program executable on a general purpose computing device, wherein the program is capable of demodulating a multi-carrier modulated (MCM) received signal, the computer program comprising:
- (a) a first set of instructions for calculating channel state information (CSI) for each carrier used in the MCM received signal;
- (b) a second set of instructions for de-mapping the MCM received signal based on the CSI calculated by the first set of instructions;
- (c) a third set of instructions for generating decision data based on the CSI calculated by the first set of instructions;
- and
- (d) a fourth set of instructions for decoding the decision data.
Dependencies are inferred from the claim text.