Browse Prior Art Database

Coordinated AP/MS MCS Shift For Good Coverage Users

IP.com Disclosure Number: IPCOM000175666D
Original Publication Date: 2008-Oct-17
Included in the Prior Art Database: 2008-Oct-17
Document File: 2 page(s) / 196K

Publishing Venue

Motorola

Related People

John Harris: INVENTOR [+2]

Abstract

We are seeking to maximize mobile battery life while minimizing/avoiding degradation to wireless system performance. This paper addresses this problem, in the context of a mobile station which has 2 receive antennas. The mobile station principally has two options: 1) The first option is that the mobile station can power up 2 separate receivers, where each receiver processes the output from each antenna separately/independently. This option results in more battery drain (because two different receivers are being powered instead of just a single receiver), but it also results in better RF performance because the results from each receiver are largely independent/uncorrelated. 2) The second option is that the mobile simply combines the input from each antenna and uses a single receiver to decode the output from this combined antenna signal. This option results in less battery drain (because only a single receiver needs to be powered), but it also results in worse RF performance because the uncorrelated or independent information from each of the antennas are not considered in isolation. As a result, the mobile station can use the second option above to save battery life. However, this second option may also reduce system capacity. This paper proposes some specific mechanisms to achieve these battery life gains while minimizing the resulting system capacity/performance costs to the wireless link.

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Coordinated AP/MS MCS Shift For Good Coverage Users

John Harris, Aart-Jan Geurtsen

Motorola

I.                   Problem

                  We are seeking to maximize mobile battery life while minimizing/avoiding degradation to wireless system performance. This paper addresses this problem, in the context of a mobile station which has 2 receive antennas. The mobile station principally has two options:

1)      The first option is that the mobile station can power up 2 separate receivers, where each receiver processes the output from each antenna separately/independently.  This option results in more battery drain (because two different receivers are being powered instead of just a single receiver), but it also results in better RF performance because the results from each receiver are largely independent/uncorrelated.

2)      The second option is that the mobile simply combines the input from each antenna and uses a single receiver to decode the output from this combined antenna signal.  This option results in less battery drain (because only a single receiver needs to be powered), but it also results in worse RF performance because the uncorrelated or independent information from each of the antennas are not considered in isolation.

As a result, the mobile station can use the second option above to save battery life.  However, this second option may also reduce system capacity.  This paper proposes some specific mechanisms to achieve these battery life gains while minimizing the resulting system capacity/performance costs to the wireless link.

II.                Solution Proposed

The mobile station may base its decision as to whether to use option 1 or 2 (as defined in the introduction) based on at least one of:

n      battery life

n      loading

n      signal strength.

One solution for achieving this is to have the cellular infrastructure advertise when the mobile station is allowed to report its signal strength based on a one or two stage receiver.  In this case, the infrastructure would advertise that a two-stage receiver must be used when the system is overloaded, and/or the mobile station has poor signal strength, and/or the mobile station has more than a threshold amount of battery life remaining (or is connected to a fixed power source).  If a mobile station satisfies these criteria for reporting signal strength based on a one stage receiver, then it would base its CQI report on a single stage receiver.

Under this approach, the infrastructure does not need to know if the MS is transmitting signal strength based on a single receiver or two receivers.  The infrastructure will simply schedule the mobile based on whatever signal strength the m...