US 8,947,996 B2Granted

Offset modulation orthogonal frequency division multiplexing (OFDM) and multi-access transmission method with cyclic prefix (CP)

AssigneeSoutheast University

InventorsXiqi Gao, Wenjin Wang, Xiaohu You, Xianggen Xia, Guochen Ou

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Abstract

The present invention provides an Offset Modulation Orthogonal Frequency Division Multiplexing (OFDM) and multi-access transmission method with a Cyclic Prefix (CP), including a generating method of the sent signal in the sending terminal and a processing method of the received signal in the receiving terminal, the method includes: in the sending terminal, performing generalized discrete Fourier Transform on real-value digital baseband modulated symbols and obtaining the frequency-domain signal; performing conjugate symmetric extension, frequency-domain filtering, sub-carrier mapping on the frequency-domain signal; performing Inverse Fast Fourier Transform on the frequency-domain signal after sub-carrier mapping; inserting a CP and obtaining the time-domain sent signal; in the receiving terminal, including: removing the CP, performing Fast Fourier Transform on CP removed symbols and obtaining the frequency-domain received signal; and based on multiple user joint frequency-domain equalization performing iterative detection decoding on the frequency-domain received signal. The present invention can obtain the low-signal envelope volatility in the condition of remaining spectrum efficiency, and adopting iterative received signal processing method based on multiple user joint frequency-domain equalization ensures the transmission reliability with low-complexity.

Claims7

Dependent claims

An offset modulation-orthogonal frequency division multiplexing (OM-OFDM) transmission method with cyclic prefix, wherein the transmission method includes a method for generating transmitted signals and a method for processing received signals,

wherein, the method for generating transmitted signals includes the following steps:
a. performing channel encoding and symbol mapping for the transmitted information bits, to obtain digital baseband modulation symbols with real values;
b. dividing the digital baseband modulation symbols into K streams, wherein, K is a positive integer;
c. performing serial/parallel conversion in length 2Nd for the digital baseband modulation symbols in stream k, to obtain a transmitted symbol vector dk,l length 2Nd in the stream, wherein, Nd is a positive integer, suffix l represents sequence number of block, dk,l=[dk,l(0), . . . dk,l (2Nd−1)]T, and (•)T represents conjugate transposition operation;
d. performing cyclic convolution for the transmitted symbols in each stream with the coefficient of time domain pulse shaping filter for the stream, and modulating the result in offset quadrature amplitude modulation (OQAM) mode to the frequency band corresponding to the stream, to obtain the digital baseband signals in the stream;
e. combining the digital baseband signals on all streams by summing, to obtain the transmitted signals, to which a cyclic prefix will be inserted later;
f. inserting a cyclic prefix, to obtain digital baseband transmitted signals;
and wherein, the method for processing received signals includes the following steps:
g. removing the cyclic prefix from the received signals;
h. performing band-pass filtering for the received signals for each stream, and performing combined equalization for multi-streams, perform demodulation and decoding.

7 more elements

A multi access transmission method based on offset modulation-orthogonal frequency division multiplexing (OM-OFDM) with cyclic prefix, including a method for generating transmitted signals and a method for processing received signals, wherein, the method for generating transmitted signals of user u includes the following steps:

4a. performing channel encoding and symbol mapping for the transmitted information bits, to obtain digital baseband modulation symbols with real values;
4b. performing serial/parallel conversion in length 2Nd for the digital baseband modulation symbols, to obtain transmitted symbol vector du,l, wherein N is a positive integer, d is a transmitted symbol vector, suffix u indicates a user, and suffix l represents sequence number of block;
4c. performing cyclic convolution for the transmitted symbols with the coefficient of pulse shaping filter for the user, and modulating the result in offset quadrature amplitude modulation (OQAM) mode to the frequency band corresponding to the user, to obtain the digital baseband signals of the user;
4d. inserting a cyclic prefix, to obtain digital baseband transmitted signals;
wherein, the method for processing received signals includes the following steps:
4e. removing the cyclic prefix from the received signals;
4f. performing band-pass filtering for the received signals for each user, and performing combined frequency domain equalization for multi-user, performing demodulation and decoding.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 13/574,773Filed 31 Dec 2010
Priority: CN 2010 1 001829522 Jan 2010
Published: US 2013/0148488 A113 Jun 2013
Granted: 3 Feb 2015
Term ends: Not estimatedThe source records don’t support an estimate.

Classification4 codes

H04L 27/2697
Multicarrier modulation systems: in combination with other modulation techniques
H04L 27/2698
In combination with other modulation techniques: double density OFDM/OQAM system, e.g. OFDM/OQAM-IOTA system
H04L 27/2607
Symbol extensions, e.g. Zero Tail, Unique Word [UW]: cyclic extensions
H04L
Digital communication