Signal generation method and signal generation device

• US 9,461,725 B2
• Filed: 01/21/2016
• Issued: 10/04/2016
• Est. Priority Date: 12/10/2010
• Status: Active Grant

• Current Assignee: Sun Patent Trust
• Original Assignee: Sun Patent Trust
• Inventors: Murakami, Yutaka, Kimura, Tomohiro, Ouchi, Mikihiro
• Primary Examiner(s): Huynh, Dung B
• Application Number:
  US15/003,419
• Publication Number:
  US 20160142118A1
• Time in Patent Office: 257 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G06F 11/10 Adding special bits or symbols to the coded information, e.g. parity check, casting out 9's or 11's
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/0456 Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
• CPC Class Codes: H04B 7/0482 Adaptive codebooks
• CPC Class Codes: H04B 7/0669 using different channel coding between antennas space-time coding H04L1/0618
• CPC Class Codes: H04B 7/0682 using phase diversity (e.g. phase sweeping)
• CPC Class Codes: H04B 7/0697 using spatial multiplexing
• CPC Class Codes: H04L 1/0058 Block-coded modulation
• CPC Class Codes: H04L 25/0224 using sounding signals
• CPC Class Codes: H04L 25/03898 codebook-based design selection of codebook or precoding matrix for MIMO diversity systems H04B7/0456
• CPC Class Codes: H04L 25/067 providing soft decisions, i.e. decisions together with an estimate of reliability H04L25/068 and H04L25/069 take precedence; sequence estimation techniques H04L25/03178
• CPC Class Codes: H04L 27/2627 Modulators
• CPC Class Codes: H04L 5/005 of common pilots, i.e. pilots destined for multiple users or terminals
• CPC Class Codes: H04W 72/044 based on the type of the allocated resource

Abstract

A transmission method simultaneously transmitting a first modulated signal and a second modulated signal at a common frequency performs precoding on both signals using a fixed precoding matrix and regularly changes the phase of at least one of the signals, thereby improving received data signal quality for a reception device.

Claims

1. An OFDM signal generation method of a transmission system, the transmission system having a first transmitter and a second transmitter, the OFDM signal generation method comprising:

encoding input data to coded blocks each made up of a plurality of bits by using a predetermined error correction block coding scheme;

modulating each of the coded blocks to a first modulated signal s1 and a second modulated signal s2, data included in the first modulated signal s1 being same as data included in the second modulated signal s2;

applying precoding by a fixed matrix F to the first modulated signal s1 and the second modulated signal s2 to obtain a first pre-coded signal z1′ and

a second pre-coded signal z2′

, wherein

the matrix F is expressed as;

2. An OFDM signals generation system comprising:

a first OFDM signal generator; and

a second OFDM signal generator,

wherein both the first OFDM signal generator and the second OFDM signal generator are operable to;

encode input data to coded blocks each made up of a plurality of bits by using a predetermined error correction block coding scheme;

modulate each of the coded blocks to a first modulated signal s1 and a second modulated signal s2, data included in the first modulated signal s1 being same as data included in the second modulated signal s2;

apply precoding by a fixed matrix F to the first modulated signal s1 and the second modulated signal s2 to obtain a first pre-coded signal z1′ and

a second pre-coded signal z2′

, wherein

the matrix F is expressed as;

3. A reception data generation method of a reception apparatus, the method comprising:

acquiring a reception signal obtained by converting a first OFDM signal transmitted from a first antenna of a first transmitter at a first period at a first frequency and a second OFDM signal transmitted from a second antenna of a second transmitter at the first period at the first frequency, the first OFDM signal and the second OFDM signal having been generated through a predetermined generation process; and

demodulating the reception signal to reception data, through a demodulation process corresponding to the predetermined generation process, wherein

at least one of the acquiring and the demodulating is performed by the reception apparatus, and

the predetermined generation process is a process of;

encoding input data to coded blocks each made up of a plurality of bits by using a predetermined error correction block coding scheme;

modulating each of the coded blocks to a first modulated signal s1 and a second modulated signal s2, data included in the first modulated signal s1 being same as data included in the second modulated signal s2;

applying precoding by a fixed matrix F to the first modulated signal s1 and the second modulated signal s2 to obtain a first pre-coded signal z1′ and

a second pre-coded signal z2′

, wherein

the matrix F is expressed as;

4. A reception data generation apparatus comprising:

a memory; and

control circuitry,

wherein the control circuitry is operable to perform the steps of;

acquiring a reception signal obtained by converting a first OFDM signal transmitted from a first antenna of a first transmitter at a first period at a first frequency and a second OFDM signal transmitted from a second antenna of a second transmitter at the first period at the first frequency, the first OFDM signal and the second OFDM signal having been generated through a predetermined generation process; and

demodulating the reception signal to reception data, through a demodulation process corresponding to the predetermined generation process, wherein

at least one of the acquiring and the demodulating is performed by the control circuitry, and

the predetermined generation process is a process of;

encoding input data to coded blocks each made up of a plurality of bits by using a predetermined error correction block coding scheme;

modulating each of the coded blocks to a first modulated signal s1 and a second modulated signal s2, data included in the first modulated signal s1 being same as data included in the second modulated signal s2;

applying precoding by a fixed matrix F to the first modulated signal s1 and the second modulated signal s2 to obtain a first pre-coded signal z1′ and

a second pre-coded signal z2′

, wherein

the matrix F is expressed as;