TRANSMISSION METHOD AND TRANSMISSION APPARATUS

• US 20120219089A1
• Filed: 02/28/2012
• Published: 08/30/2012
• Est. Priority Date: 02/28/2011
• Status: Active Grant

• Current Assignee: Sun Patent Trust
• Original Assignee: Panasonic Intellectual Property Corporation of America (Panasonic Holdings Corporation)
• Inventors: MURAKAMI, Yutaka, KIMURA, Tomohiro, OUCHI, Mikihiro
• Granted Patent: US 8,638,879 B2
• Time in Patent Office: Days
• US Class Current: 375/296
• CPC Class Codes: H04B 7/0456 Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
• CPC Class Codes: H04L 1/005 Iterative decoding, including iteration between signal detection and decoding operation
• CPC Class Codes: H04L 1/0643 block codes
• CPC Class Codes: H04L 25/0204 of multiple channels
• CPC Class Codes: H04L 25/0222 Estimation of channel variability, e.g. coherence bandwidth, coherence time, fading frequency
• CPC Class Codes: H04L 25/0242 using matrix methods
• CPC Class Codes: H04L 25/03942 switching between different codebooks
• 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 27/2604 Multiresolution systems by means of multiresolution subcarriers H04L27/183, H04L27/3488
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver

Abstract

All data symbols used in data transmission of a modulated signal are precoded by switching between precoding matrices so that the precoding matrix used to precode each data symbol and the precoding matrices used to precode data symbols that are adjacent to the data symbol along the frequency axis and the time axis all differ. A modulated signal with such data symbols arranged therein is transmitted.

Claims

1. A transmission method for generating, from a plurality of baseband signals, a plurality of precoded signals to be transmitted over the same frequency bandwidth at the same time and transmitting the generated precoded signals, comprising the steps of:

selecting a matrix F[i] from among N matrices while switching between the N matrices, the N matrices defining precoding performed on the plurality of baseband signals, i being an integer from 0 to N−

1; and

generating a first precoded signal z1 and a second precoded signal z2 by precoding, in accordance with the selected matrix F[i], a first baseband signal s1 generated from a first plurality of bits and a second baseband signal s2 generated from a second plurality of bits, a first encoded block and a second encoded block being generated respectively as the first plurality of bits and the second plurality of bits using a predetermined error correction block encoding method, the first baseband signal s1 and the second baseband signal s2 being generated respectively from the first encoded block and the second encoded block to have M symbols each, the first precoded signal z1 and the second precoded signal z2 being generated to have M slots each by precoding a combination of the first baseband signal s1 and the second baseband signal s2, wherein

in each of the first precoded signal z1 and the second precoded signal z2, the M slots are arranged such that at least one of the following conditions is met;

(i) the M slots are at different frequencies from one another, and (ii) the M slots are at different times from one another,

the first precoded signal z1 is transmitted from a first antenna,

the second precoded signal z2 is transmitted from a second antenna,

the first precoded signal z1 and the second precoded signal z2 satisfy the equation (z1, z2)^T=F[i](s1, s2)^T, and

in each of the first precoded signal z1 and the second precoded signal z2,

the M slots include a first slot, a second slot, a third slot, a fourth slot, and a fifth slot,

the first slot is at a first frequency and a first time, two frequencies that are adjacent to the first frequency in a frequency domain are respectively a second frequency and a third frequency, and two times that are adjacent to the first time in a time domain are respectively a second time and a third time,

the second slot is at the first time and the second frequency, the third slot is at the first time and the third frequency, the fourth slot is at the second time and the first frequency, and the fifth slot is at the third time and the first frequency, and

each of the second to fifth slots is precoded by using one of the N matrices that is different from a matrix F[i] used in precoding the first slot.

2. A transmission apparatus for generating, from a plurality of baseband signals, a plurality of precoded signals to be transmitted over the same frequency bandwidth at the same time and transmitting the generated precoded signals, comprising:

a weighting information generation unit configured to select a matrix F[i] from among N matrices while switching between the N matrices, the N matrices defining precoding performed on the plurality of baseband signals, i being an integer from 0 to N−

1;

a weighting unit configured to generate a first precoded signal z1 and a second precoded signal z2 by precoding, in accordance with the selected matrix F[i], a first baseband signal s1 generated from a first plurality of bits and a second baseband signal s2 generated from a second plurality of bits;

an error correction coding unit configured to generate a first encoded block as the first plurality of bits and a second encoded block as the second plurality of bits using a predetermined error correction block encoding method;

a mapping unit configured to generate the first baseband signal s1 and the second baseband signal s2 respectively from the first encoded block and the second encoded block, the first baseband signal s1 and the second baseband signal s2 having M symbols each;

a first antenna from which the first precoded signal z1 is transmitted; and

a second antenna from which the second precoded signal z2 is transmitted, wherein

the first precoded signal z1 and the second precoded signal z2 satisfy the equation (z1, z2)^T=F[i](s1, s2)^T,

the weighting unit generates the first precoded signal z1 and the second precoded signal z2 having M slots each, by precoding a combination of the first baseband signal s1 generated from the first encoded block and the second baseband signal s2 generated from the second encoded block, and

in each of the first precoded signal z1 and the second precoded signal z2,

the M slots are arranged such that at least one of the following conditions is met;

(i) the M slots are at different frequencies from one another, and (ii) the M slots are at different times from one another,

the M slots include a first slot, a second slot, a third slot, a fourth slot, and a fifth slot,

the first slot is at a first frequency and a first time, two frequencies that are adjacent to the first frequency along in a frequency domain are respectively a second frequency and a third frequency, and two times that are adjacent to the first time along in a time domain are respectively a second time and a third time,

the second slot is at the first time and the second frequency, the third slot is at the first time and the third frequency, the fourth slot is at the second time and the first frequency, and the fifth slot is at the third time and the first frequency, and

each of the second to fifth slots is precoded by using one of the N matrices that is different from a matrix F[i] used in precoding the first slot.