Signal generation method and signal generation device

• US 10,644,768 B2
• Filed: 04/02/2019
• Issued: 05/05/2020
• 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:
  US16/373,119
• Publication Number:
  US 20190229782A1
• Time in Patent Office: 399 Days
• 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 generating method comprising:

mapping, by the first transmitter, one or more coded blocks to a first mapped signal s1, the one or more coded blocks generated by using a determined error correction block coding scheme;

mapping, by the second transmitter, the one or more coded blocks to a second mapped signal s2, data included in the first mapped signal s1 being same as data included in the second mapped signal s2;

inserting, by the first transmitter, one or more pilots to the first mapped signal s1 to obtain a first pilot-inserted signal sp1;

inserting, by the second transmitter, the one or more pilots to the second mapped signal s2 to obtain a second pilot-inserted signal sp2;

phase-changing, by the first transmitter, the first pilot-inserted signal sp1 for each of a plurality of slots to obtain a first transmission signal z1 by using a first scheme of a regularly varying phase change process;

phase-changing, by the second transmitter, the second pilot-inserted signal sp2 for each of the plurality of slots to obtain a second transmission signal z2 by using a second scheme of the regularly varying phase change process;

converting, by the first transmitter, the first transmission signal z1 for each of the plurality of slots to a first OFDM signal for each of a plurality of subcarriers;

converting, by the second transmitter, the second transmission signal z2 for each of the plurality of slots to a second OFDM signal for each of the plurality of subcarriers;

inserting, by the first transmitter, one or more first symbols to enable synchronization to the first OFDM signal to be transmitted from a first antenna at a first period at a first frequency; and

inserting, by the second transmitter, one or more second symbols to enable synchronization to the second OFDM signal to be transmitted from a second antenna at the first period at the first frequency.

2. An OFDM signal generation system comprising:

a first OFDM signal generating circuit; and

a second OFDM signal generating circuit,

wherein the first OFDM signal generating circuit, in operation,

maps one or more coded blocks to a first mapped signal s1, the one or more coded blocks generated by using a determined error correction block coding scheme;

inserts one or more pilots to the first mapped signal s1 to obtain a first pilot-inserted signal sp1;

phase-changes, while regularly varying a first scheme of phase change for each of a plurality of slots, the first pilot-inserted signal sp1 for each of the plurality of slots to obtain a first transmission signal z1;

converts the first transmission signal z1 for each of the plurality of slots to a first OFDM signal for each of a plurality of subcarriers;

inserts one or more first symbols to enable synchronization to the first OFDM signal to be transmitted from a first antenna at a first period at a first frequency; and

wherein the second OFDM signal generating circuit, in operation,

maps the one or more coded blocks to a second mapped signal s2, data included in the first mapped signal s1 being same as data included in the second mapped signal s2;

inserts the one or more pilots to the second mapped signal s2 to obtain a second pilot-inserted signal sp2;

phase-changes the second pilot-inserted signal sp2 for each of the plurality of slots to obtain a second transmission signal z2 by using a second scheme of the regularly varying phase change process;

converts the second transmission signal z2 for each of the plurality of slots to a second OFDM signal for each of the plurality of subcarriers; and

inserts one or more second symbols to enable synchronization to the second OFDM signal to be transmitted from a second antenna at the first period at the first frequency.

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 by using one or more first symbols to enable synchronization and one or more second symbols to enable synchronization, the first OFDM signal and the second OFDM signal having been generated through a determined generation process; and

de-mapping the reception signal to reception data, through a de-map process corresponding to the determined generation process, wherein

the determined generation process is a process of;

mapping, by the first transmitter, one or more coded blocks to a first mapped signal s1, the one or more coded blocks generated by using a determined error correction block coding scheme;

mapping, by the second transmitter, the one or more coded blocks to a second mapped signal s2, data included in the first mapped signal s1 being same as data included in the second mapped signal s2;

inserting, by the first transmitter, one or more pilots to the first mapped signal s1 to obtain a first pilot-inserted signal sp1;

inserting, by the second transmitter, the one or more pilots to the second mapped signal s2 to obtain a second pilot-inserted signal sp2;

phase-changing, by the first transmitter, the first pilot-inserted signal sp1 for each of the plurality of slots to obtain a first transmission signal z1 by using a first scheme of a regularly varying phase change process;

phase-changing, by the second transmitter, the second pilot-inserted signal sp2 for each of the plurality of slots to obtain a second transmission signal z2 by using a first scheme of the regularly varying phase change process;

converting, by the first transmitter, the first transmission signal z1 for each of the plurality of slots to the first OFDM signal for each of a plurality of subcarriers;

converting, by the second transmitter, the second transmission signal z2 for each of the plurality of slots to the second OFDM signal for each of the plurality of subcarriers;

inserting, by the first transmitter, the one or more first symbols to enable synchronization to the first OFDM signal to be transmitted from the first antenna at the first period at the first frequency; and

inserting, by the second transmitter, the one or more second symbols to enable synchronization to the second OFDM signal to be transmitted from the second antenna at the first period at the first frequency.

4. A reception data generation apparatus comprising:

a memory; and

control circuitry,

wherein the control circuitry, in operation, performs 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 by using one or more first symbols to enable synchronization and one or more second symbols to enable synchronization, the first OFDM signal and the second OFDM signal having been generated through a determined generation process; and

de-mapping the reception signal to reception data, through a de-map process corresponding to the determined generation process, wherein

the determined generation process is a process of;

mapping, by the first transmitter, one or more coded blocks to a first mapped signal s1, the one or more coded blocks generated by using a determined error correction block coding scheme;

mapping, by the second transmitter, the one or more coded blocks to a second mapped signal s2, data included in the first mapped signal s1 being same as data included in the second mapped signal s2;

inserting, by the first transmitter, one or more pilots to the first mapped signal s1 to obtain a first pilot-inserted signal sp1;

inserting, by the second transmitter, the one or more pilots to the second mapped signal s2 to obtain a second pilot-inserted signal sp2;

phase-changing, by the first transmitter, the first pilot-inserted signal sp1 for each of the plurality of slots to obtain a first transmission signal z1 by using a first scheme of a regularly varying phase change process;

regularly phase-changing, by the second transmitter, the second pilot-inserted signal sp2 for each of the plurality of slots to obtain a second transmission signal z2 by using a second scheme of the regularly varying phase change process;

converting, by the first transmitter, the first transmission signal z1 for each of the plurality of slots to the first OFDM signal for each of a plurality of subcarriers;

converting, by the second transmitter, the second transmission signal z2 for each of the plurality of slots to the second OFDM signal for each of the plurality of subcarriers;

inserting, by the first transmitter, the one or more first symbols to enable synchronization to the first OFDM signal to be transmitted from the first antenna at the first period at the first frequency; and

inserting, by the second transmitter, the one or more second symbols to enable synchronization to the second OFDM signal to be transmitted from the second antenna at the first period at the first frequency.