Method and device for data compression, transmission, and decompression

Patent metadata

Field	Value
Publication number	US-9515737-B2
Application number	US-201314422896-A
Country	US
Kind code	B2
Filing date	Jul 30, 2013
Priority date	Aug 21, 2012
Publication date	Dec 6, 2016
Grant date	Dec 6, 2016

Abstract

Disclosed are a method and device for data compression, transmission, and decompression. In the present method, data-to-be-transmitted is grouped by a transmitting terminal, and for each group: a shift factor is determined based on the most significant bit of sample data of the greatest value in the group when a sign bit is removed, data bits of the sample data in the group are left shifted by the shift factor; the left shifted sample data respectively are quantified, thus making the bit number of the quantified sample data to be equal to a predefined bit number; the shift factor and the quantified sample data are transmitted to a receiving terminal. Employment of the present application optimizes data compression performance.

First claim

The invention claimed is:

1. A method for compressing and transmitting data, the method comprising:
grouping, by a transmitting terminal, the data to be transmitted into a plurality of groups so that each of the groups comprises at least one data sample, each of the at least one data sample comprises a sign bit, a plurality of data bits representing plural real data components, and a plurality of data bits representing plural imaginary data components; and
for each of the groups, determining, by the transmitting terminal, a shift factor according to a most significant bit of one of the at least one data sample, which has a largest value excluding a sign bit; left-shifting the data bits of the at least one data sample by the shift factor to produce at least one left-shifted data sample; quantizing the at least one left-shifted data sample to produce at least one quantized data sample including a plural number of bits so that the number of the bits of each of the at least one quantized data sample is equal to a predefined bit number; and transmitting the shift factor and the at least one quantized data sample to a receiving terminal.

2. The method according to claim 1 , wherein when the data to be transmitted consists of a real component (I data) and an imaginary component (Q data) of data (IQ data) to be transmitted on a plurality of antennas, the grouping the data to be transmitted comprises:
grouping the IQ data to be transmitted on each of the plurality of antennas separately, and grouping the I data and the Q data separately so that at least one consecutive I data to be transmitted on one of the antennas are grouped together or at least one consecutive Q data to be transmitted on one of the antennas are grouped together; or
grouping the IQ data to be transmitted on each of the plurality of antennas separately; and grouping the l data and the Q data jointly so that at least one consecutive data and at least one consecutive Q data to be transmitted on one of the antennas are grouped together; or
grouping the IQ data to be transmitted on the plurality of antennas jointly, and grouping the I data and the Q data separately so that the I data to be transmitted on the antennas at same time locations are grouped together or the Q data to be transmitted on the antennas at the same time locations are grouped together; or
grouping the IQ data to be transmitted on the plurality of antennas jointly, and grouping the I data and the Q data jointly so that the I data and the Q data to be transmitted on the antennas at the same time locations are grouped together; or
grouping the IQ data to be transmitted on the plurality of antennas jointly, and grouping the I data and the Q data separately so that at least one consecutive I data to be transmitted on the antennas at the same time locations are grouped together or at least one consecutive Q data to be transmitted on the antennas at the same time locations are grouped together; or
grouping the IQ data to be transmitted on the plurality of antennas jointly, and grouping the I data and the Q data jointly so that at least one consecutive I data and Q data to be transmitted on the antennas at the same time locations are grouped together.

3. The method according to claim 1 , wherein the determining the shift factor according to the most significant bit of one of the at least one data sample which has the largest value excluding the sign bit comprises:
determining a largest number of shift bits which can be represented by the shift factor;
determining the one of the at least one data sample, which has the largest value excluding the sign bit, and a bit index of the most significant bit of the one of the at least data sample excluding the sign bit; and
if A is no larger than the largest number of shift bits, then determining the shift factor to be equal to A; otherwise, determining the shift factor to be equal to the largest number of shift bits, wherein A=W−1−H, W represents the number of bits of the one of the at least one data sample excluding the sign bit, and H represents the bit index of the most significant bit.

4. The method according to claim 3 , wherein the largest number C of shift bits which can be represented by the shift factor is determined in the equation of:
C= 2^( n*k/ 2)−1,

wherein ^ represents the power, n represents the number of the at least one data sample, and k represents the number of control bits in which the shift factor is transmitted.

5. The method according to claim 3 , wherein after the step of determining the largest number of shift bits which can be represented by the shift factor, and before the step of determining the one of the at least one data sample, which has the largest value excluding the sign bit and the bit index of the most significant bit of the one of the at least one data sample excluding the sign bit, the method further comprises:
if the bit index of the most significant bit of the one of the at least one data sample, which has the largest value excluding the sign bit, is E, or there are more than a preset proportion of the data sample among the at least one data samples, of which the bit index of the most significant bit with the sign bit being excluded is smaller than or equal to E, then limiting each of the at least one data samples into E bits, wherein E represents an integer larger than 0.

6. The method according to claim 1 , wherein the quantizing the at least one left-shifted data samples to produce at least one quantized data sample comprises:
for each of the at least one left-shifted data sample, maintaining the sign bit, capturing (V−1) hits of data starting from the most significant bit to least significant hit among the data bits, and forming the quantized data sample from the sign bit and the captured bits of data, wherein V represents the redefined bit number.

7. The method according to claim 1 , wherein the transmitting terminal is a Radio Remote Unit (RRU), and the receiving terminal is a Base Band Unit (BBU); or
the transmitting terminal is a BBU, and the receiving terminal is an RRU.

8. A method for decompressing data, the method comprising:
receiving, by a receiving terminal, a shift factor, and at least one data sample quantized by a transmitting terminal, each of the at least one data sample comprising a sign bit, a plurality of data bits representing plural real data components, and a plurality of data bits representing plural imaginary data components;
de-quantizing, by the receiving terminal, the at least one data sample to produce at least one de-quantized data sample, so that a number of bits of each of the at least one de-quantized data sample is equal to a number of the bits of the at least one data sample without being quantized by the transmitting terminal, wherein each of the at least one data sample without being quantized by the transmitting terminal comprises a sign bit and a plurality of data bits; and
right-shifting, by the receiving terminal, data bits of the at least one de-quantized data sample by the shift factor to obtain at least one decompressed data sample.

9. The method according to claim 8 , wherein the de-quantizing, by the receiving terminal, the at least one data sample comprises:
padding B zeros to a right side of each of the at least one data sample to obtain the at least one de-quantized data sample, wherein B=W−V, W represents a number of the bits of each of the at least one data sample without being quantized excluding the sign bit, and V represents a number of the bits of each of the at least one data sample quantized.

10. The method according to claim 9 , wherein after the step of de-quantizing, and before the step of right-shifting, the method further compri

Assignees

• China Academy Telecommunications Technology

Inventors

• Luo Feiqiong
• Ren Bin
• Li Qiong

Classifications

• H04L69/04

  Protocols for data compression, e.g. ROHC · CPC title

• H04L27/366

  Arrangements for compensating undesirable properties of the transmission path between the modulator and the demodulator · CPC title

• H03M7/14

  Conversion to or from non-weighted codes · CPC title

• H04B10/25753 Primary

  Distribution optical network, e.g. between a base station and a plurality of remote units · CPC title

• H04L5/0023

  Time-frequency-space · CPC title